Answer:
There are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.
Explanation:
We can calculate the number of moles (η) of BeO as follows:
[tex] \eta = \frac{m}{M} [/tex]
Where:
m: is the mass = 250 g
M: is the molar mass = 25.0116 g/mol
Hence, the number of moles is:
[tex] \eta = \frac{250 g}{25.0116 g/mol} = 10.0 moles [/tex]
Therefore, there are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.
I hope it helps you!
Show the starting diene and dienophile you could use to prepare the following molecule: CO2CH3 Diene + Dienophile- O Use the wedge/hash bond tools to indicate stereochemistry where it exists.
O If a group is achiral, do not use wedged or hashed bonds on it. O Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. O Separate multiple reactants using the + sign from the drop-down menu. ору 88te
Diene: These compounds have a double bond that is conjugated. Dienophile: At least one pi bond exists in these compounds. And occasionally, these pi bonds joined together after some electron withdrawal.
Examples of stereochemistry and what it is:The field of chemistry known as stereochemistry is concerned with "the study of the various spatial configurations of atoms in molecules." The methodical presentation of a particular area of science and technology, known as stereochemistry, typically necessitates a little detour into the past.
How would you define stereochemistry?a discipline of chemistry that examines the spatial configuration of atoms and groups in molecules, as well as how that configuration relates to the attributes of a substance.
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The dipole moment of BrCl is 0.518 D and the distance between atoms is 213.9 pm.
Part A
What is the percent ionic character of the BrCl bond?
The percent ionic character of the BrCl bond is 0.0505%.
How to calculate the percent ionic character?One way to calculate the percent ionic character is to multiply the measured dipole moment by the value of eR, then multiply that result by 100. When one charge is totally transferred during the creation of the bond and the subsequent ions are spherical, the value of eR is the value of the dipole moment.We must understand that a difference in electronegativity leads to an increase in the polarity of the connection and the ionic nature. By computing the charge on each atom, we can get the % ionic character. The ionic character percent is determined by dividing the original charge by the charge that is present on a single electron.Here I attached the calculation
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design a synthesis of 2-methyl-2-propanol from 2-methylpropane.
Synthesis is an analysis method that includes the steps of comparing and contrasting, categorising, and dividing.
What is the meaning of synthesis?
Comparing and contrasting, categorising, and dividing are all aspects of the analysis technique known as synthesis. Synthesis, at its most fundamental level, is the combination of two or more sources while searching for common themes. Finding connections between disparate materials to support your argument is the goal of synthesis.
2-Methylpropene must be changed into 2-Methyl-2-Propanol using a. H2 O/H+. Using an addition reaction, the alkene will be transformed into the necessary alcohol.
Alkene and water react with an acidic medium to produce alcohols in a process known as acid catalysed hydration. As dictated by Markovnikov's rule, this reaction occurs. An acid catalyst and water combine to generate 2-methylpropan-2-ol from 2-methylpropene.
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After the rising phase, which ion channel is responsible for action potential returning to its
resting Vm and why?
A. Na+ channels, because positive Na* ions are at higher concentration outside the axon than inside, and so they enter the axon and raise Vm
B. Na+ channels, because positive Na+ ions are at higher concentration inside the axon than outside, and so they leave the axon and raise Vm
C. K* channels, because positive K+ ions are at higher concentration outside the axon than inside, and so they enter the axon and raise Vm
D. K channels, because positive K* ions are at higher concentration inside the axon than outside, and so they leave the axon and lower V m
Na+ channels enter the neuron and increase Vm because the positive Na+ ions are more abundant concentration outside the cell than inside.
The ratio of a constituent's abundance to the total volume of the mixture is its concentration. Mass concentration, molar concentration, number concentration, and volume concentration are a few of the various categories of mathematical description. Information is sent via neurons. Electrical impulses and chemical signals are used to transport information inside different brain areas as well as between the brain and the rest of the nervous system. The two primary subtypes of brain cells are neurons and glial cells. Although they play a supporting role in the brain, glial cells predominate over neurons in numerous areas of the organ.
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What is the major product obtained from the addition of HBr to the following compound?
1-Bromo-4-methylpentane is the main byproduct of the addition reaction of HBr to 4-methylpent-1-ene in the presence of peroxide.
What is methyl pentane?A branched-chain alkane with the chemical formula C₆H₁₄ is 2-methylpentane, also known as is hexane. A methyl group is attached to the second carbon atom in a pentane chain to form this structural isomer of hexane. A methyl group is substituted at position 3 of the alkane 3-methylpentane, which is pentane. It serves as a lubricant, a solvent in chemical synthesis, and a starting point for making carbon black. It functions as an allelochemical, a human metabolite, and a non-polar solvent. To make the secondary alcohol 3-methyl-2-pentanol, a hydroxy group is added to position 2 of 3-methylpentane. It performs three different roles: biomarker, human xenobiotic metabolite, and plant metabolite.The complete question is:
The major product obtained by the addition reaction of HBr to 4-methylpent-1-ene in the presence of peroxide is:
A) 1-Bromo-4-methylpentane
B) 4-bromo-2-methylpentane
C) 2-bromo-4-methylpentane
D) 3-bromo-2-methylpentane
E) 2-bromo-2-methylpentane
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5. Give two examples of native Hawaiian living matter.
Which of the following choices is an example of an acquired trait?
a human is born with brown eyes
a dog’s ears are bandaged so that they stand upright and her tail is docked short
a horse is born with a light-colored mane
a cat is born with black and white fur
Answer:
a dog’s ears are bandaged so that they stand upright and her tail is docked short
Explanation:
The dog is not born with ears that stand up or a short tail, therefore they are acquired traits.
design a synthesis of 2-bromo-1-butyl-4-nitrobenzene from benzene.
A synthesis of 2-bromo-1-butyl-4-nitrobenzene from benzene is Benzene → Nitration → 2-Nitrobenzene → Bromination → 2-Bromo-nitrobenzene → Alkylation → 2-bromo-1-butyl-4-nitrobenzene. The figure is attached below.
The synthesis of 2-bromo-1-butyl-4-nitrobenzene from benzene can be achieved in several steps.
1. Nitration of benzene: Benzene is nitrated by treating it with a mixture of concentrated nitric acid and sulfuric acid, known as fuming nitric acid. This reaction produces nitrobenzene as the main product.
2. Bromination of the Nitrobenzene: Nitrobenzene is then brominated using bromine in the presence of a Lewis acid such as aluminum bromide. This reaction produces 2-bromo-nitrobenzene as the main product.
3. Alkylation of 2-bromo-nitrobenzene: The 2-bromo-nitrobenzene is then alkylated with 1-butyl lithium to give 2-bromo-1-butyl-4-nitrobenzene as the final product.
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Predict the major organic product that results from hydrogenation of the given alkene as specified. * Use the wedge hash bond tools to indicate stereochemistry where it exists. * You do not have to explicitly draw H atoms.
* If a group is achiral, do not use wedged or hashed bonds on it.
* In cases where there is more than one answer, just draw one.
In order to give shortenings a hard firmness and plasticity and allow for the manufacturing of solid and semi-solid fats, hydrogenation is the process of saturating some double bonds and converting others to trans configuration.
In the food industry, hydrogen is added to oils (in a procedure called hydrogenation) to make them more solid or "spreadable." In addition to being utilized in the production of numerous meals, including biscuits and cakes, hydrogenated oils can also be sold directly as "spreads" in the food industry. By converting all of the double bonds in the fat to single bonds during full hydrogenation, all unsaturated fats are converted into saturated fats. By substituting a portion of the double bonds with hydrogen, partial hydrogenation decreases some of the double bonds but not all of them.
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When the supplied alkene is hydrogenated, the primary organic molecule that results is a hydrocarbon. Hydrocarbons are found in natural gas, coal, and gasoline.
A hydrocarbon is an elemental chemical compound composed only of the atoms of hydrogen and carbon. Hydrocarbons, which are naturally occurring compounds, are the building blocks of crude oil, natural gas, coal, and other key energy sources. The four categories of hydrocarbons are alkanes, alkenes, alkynes, and aromatic hydrocarbons. The simplest explanation is that chemicals known as hydrocarbons are made up of both hydrogen and carbon, as well as their derivatives (alcohols,aldehydes..etc). The hierarchical series of hydrocarbons has the formula CnH2n+2 for alkanes, CnH2n for alkenes, and CnH2n-2 for alkynes. The term "hydrocarbons" refers to the most basic category of organic substances. As hinted by their name, they are made exclusively of the elements hydrogen and carbon.
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how many moles are contained in 4.131 x 10^24 particles?
To find the number of moles contained in 4.131 x 10^24 particles, we need to use Avogadro's number. Avogadro's number, denoted by N, is the number of atoms, molecules, or other entities in one mole of a substance. It is approximately equal to 6.022 x 10^23.
So, we can use this formula to find the number of moles:
moles = (number of particles) / N
Where N = 6.022 x 10^23
Substituting the given value of particles:
moles = (4.131 x 10^24 particles) / (6.022 x 10^23)
moles = (4.131 x 10^24) / (6.022 x 10^23)
moles = 0.6869
So, 4.131 x 10^24 particles contains approximately 0.6869 moles.
Calculate the pH and [S2− ] in a 0.24 M H2S solution. Assume Ka1 = 1.0 ✕ 10−7; Ka2 = 1.0 ✕ 10−19.
pH _________
[S2− ] __________ M
The supplied statement states that the pH and S²⁻ in a 0.24M H₂S solution are 3.81 & 3.92 * 10⁻¹², respectively.
What does chemistry mean by defining a solution?A continuous variation of a continuous phase of two and more chemicals in relative proportions up the point that is known as the boundary of solubility. Although concentrations of gases other solids are possible, the term "solution" is most frequently used to refer to the liquid condition of matter. There are many different types of solutions, such as soda water, salt-and-sugar solutions, and others. In a solution, each component resembles a single phase.
Firstly, we have
[tex]$$\begin{aligned}& \mathrm{K} a_1=1.0 \times 10^{-7}=\frac{\left[\mathrm{H}^{+}\right]\left[\mathrm{HS}^{-}\right]}{\left[\mathrm{H}_2 \mathrm{~S}\right]}=\frac{\times_1^2}{0.24} \\& \text { or, } x_1^2=0.24 \times 1.0 \times 10^{-7}=2.4 \times 10^{-8} \\& \text { or, } x_1=1.54 \times 10^{-4} \mathrm{M} \\& \text { i.e, }\left[\mathrm{H}^{+}\right]=\left[\mathrm{HS}^{-}\right]=1.54 \times 10^{-4} \mathrm{~m}\end{aligned}$$[/tex]
Again,
[tex]$$\begin{aligned}& \begin{aligned}k_{a_2}=1.0 \times 10^{-19}= & \frac{\left[\mathrm{H}^{+}\right]\left[\mathrm{S}^{2-}\right]}{\left[\mathrm{HS}^{-}\right]}=\frac{x_2^2}{1.54 \times 10^{-4}} \\\text { or, } x_2^2 & =1.54 \times 10^{-4} \times 1.0 \times 10^{-19} \\& =1.54 \times 10^{-23}=15.4 \times 10^{-24} \\\text { or, } \quad x_2 & =3.92 \times 10^{-12} \\\text { i.e., }\left[\mathrm{H}^{+}\right] & =\left[\mathrm{S}^{2-}\right]=3.92 \times 10^{-12} \mathrm{M}\end{aligned}\end{aligned}$$[/tex]
[tex]$$\text { Total } \begin{aligned}{\left[H^{+}\right] } & =1.54 \times 10^{-4}+3.92 \times 10^{-12} \\& =1.54 \times 10^{-4} \mathrm{~m} \text { (approximated) }\end{aligned}$$[/tex]
Thus, [tex]$p^H=-\log \left(1.54 \times 10^{-4}\right)=3.81$[/tex]
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Chemists have determined that elements with atomic numbers greater than 92 are all
radioactive. In general, their half-lives are much shorter than the age of the universe. This
means that they no longer exist in nature and have all been artificially produced by
scientists in nuclear reactions.
Elements 93 through 105 in the periodic table have been created and named, and
scientists have claimed discovery of elements 106 and 107. The transuranium elements,
as they are called, become less stable as the atomic number and mass increase. For
example, element number 93, neptunium, has a half-life of two million years, while
element number 104, kurchatovium, has a half-life of 70 seconds.
The transuranium elements are the heaviest elements that exist and are readily
fissionable when subjected to nuclear bombardment. Chemists studying these elements
and the periodic table predict that stable elements may be found around atomic numbers
114 or 126.
Based on the information in the passage, which of the following relationships appears to
be true for those elements 93 through 105?
A. The greater the half-life, the greater the radioactivity.
B. The greater the atomic number, the greater the element stability.
C. The greater the radioactivity, the greater the half-life.
OD. The greater the atomic number, the lower the half-life.
OE. The greater the atomic number, the higher the half-life.
Answer:
The correct relationship is D. The greater the atomic number, the lower the half-life.
The passage states that the transuranium elements, elements with atomic numbers greater than 92, have short half-lives and become less stable as the atomic number and mass increase. It also gives specific examples of the half-lives of neptunium (element 93) and kurchatovium (element 104) to support this claim. Thus, as the atomic number increases, the half-life of the element decreases.
what is the use of hexane in contact cement?
The main use of hexane is as a solvent to extract edible oils from seed and vegetable crops. Hexane are used as solvents for contact cement, varnishes, and inks.
What is hexane used for ?Hexanes are mostly used as a solvent. It is used to extract edible oils from seeds and vegetables and as a cleaning agent. The high levels of hexane causes mild central nervous system effects it includes dizziness, slight nausea, and headache etc.
In the construction industry, the hexane is an effective chemical which is use as the strongest organic solvents. It dissolves chemical material which allows the objects to bind together to form a strong force.
Thus, Hexane are used as solvents for contact cement, varnishes, and inks.
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Which can conduct heat faster metal or air ( gas)? Explain your answer.
Metals conduct heat faster than air. Air or gas heats up by way of convection, whereas metals are closely packed with one another.
Which can conduct heat faster metal or air gas?substances that are poor conductors of thermal energy are called thermal insulators. Gases such as air and matter such as plastic Metal and wood are thermal insulators.
Metals and stones are examined as good conductors since they can rapidly transfer heat, whereas materials like wood, paper, air, and cloth are the poor maestros of heat. In particular, metals conduct heat better than non-metals, and solids conduct heat better than gases.
So we can conclude that All metals 'can' flatter a gas. If you heat them in a vacuum, all elemental metals can become a gas
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A 25.0 g block of copper (specific heat capacity 0.380 J/g･ °C) at 57.8 °C is placed into 500.0 g of water initially at 20.0 °C. What is the change in temperature (in °C) of the copper block? (The specific heat capacity of water is 4.184 J/g･ °C).
In order to make the heat values obtained from the equation q=mCsT equal to one another, we set them to that value. (Specific heat capacity: 0.380 J/g) 57.8 block of copper
How do you define "at capacity"?Your capacity or the quantity something can hold are both described by the word capacity. You cannot squeeze another feathery companion into a cage that is already overcrowded without risking the claustrophobia of the birds.
How come capacity is so crucial?Capacity, particularly corporate expansion, unquestionably has a quantifiable impact on every firm. Because it directly affects a company's capacity to expand, compete, and create and maintain a pleasant customer experience, capacity planning is extremely important to business success.
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Nitrogen fixation requires the hydrolysis of 8 ATPs to produce 2 NH3 molecules from 1N2.
True or False?
Nitrogen fixation does result in the release of energy, but the activation of this reaction takes energy in the form of ATP hydrolysis.
Does nitrogen fixation require ATP hydrolysis?Energy is released during the nitrogen fixation process, although ATP hydrolysis is required to start the reaction. Metallocenzymes, or proteins with metallic molecules as subunits, include nitrogenases.
This type of reaction is known as a reduction reaction because it causes N2 to gain electrons (see equation above). Due to technological challenges biochemists face in actually viewing this reaction in vitro, the precise mechanism of catalysis is unknown, and the precise order of the steps of this reaction is not fully understood.
Despite this, a lot is understood about the process. The equilibrium synthesis of ammonia from molecules of hydrogen and nitrogen has a negative enthalpy of reaction overall, which means it releases energy, but the energy barrier.
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Total cations =
Total anions =
There are eight cations (A and B) and four anions in the unit cell as shown here.
What is the unit cell?A unit cell is the smallest repeating unit in a crystal lattice structure. It is defined by the repeating pattern of atoms, ions, or molecules that make up a crystal. The unit cell can be visualized as a small box that is repeated over and over again to form the entire crystal.
The shape and size of the unit cell are unique to each type of crystal and are determined by the arrangement of atoms within the crystal. The study of unit cells is important in understanding the properties and behavior of materials at the atomic scale.
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How can kinetic energy of motion be transformed into other kinds of energy thermal energy
Answer:
Answer Below ↓
Explanation:
If the moving sand hits an obstacle, it stops due to the friction created by the contact and its kinetic energy is then transformed into thermal energy, or heat.
Maria is studying fungi in a forest. She makes some observations and takes some notes on a variety of fungi found on the forest floor. If Maria returned to the forest a year later and discovered that all the fungi were gone, what would she most likely observe as a result of this?
Answer:
Without fungi in the forest, dead and rotting materials would not be broken down, which would cause dead plants and animals to pile up in the forest.
Without fungi in the forest, dead and rotting materials would not be broken down. Fungi breaks down materials, and if fungi was not in the forest, the forest would have dead and rotting, plants and animals piled up everywhere.
Explanation: My frog taught me
Doing the test rn and says its right btw!
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A 100.-milliliter sample of helium gas is placed in a sealed container of fixed volume. As the temp of the confined gas increases from 10°c to 30°c, the internal pressure
The internal pressure of the container will increase, given that the temperature of the confined gas increases from 10 °C to 30 °C (Option B)
How do I know if the pressure will decrease, increase or remain the same?To determine if the pressure will decrease, increase or remain the same, we shall obtain the new pressure of the container. Details below
The following data were obtained from the question:
Volume = 100 mL = ConstantInitial temperature (T₁) = 10 °C = 10 + 273 = 283 K New temperature (T₂) = 30 °C = 30 + 273 = 202 KInitial pressure (P₁) = PNew pressure (P₂) = ?P₁V₁ / T₁ = P₂V₂ / T₂
Volume = contant
P₁ / T₁ = P₂ / T₂
P / 283 = P₂ / 303
Cross multiply
P₂ × 283 = P × 303
Divide both sides by 283
P₂ = (P × 303) / 283
P₂ = 1.07 × P
From the above calculation, we can see that the new pressure is 1.07 times the initial pressure.
Thus, we can conclude that the internal pressure will increase (Option B)
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Complete question:
A 100.-milliliter sample of helium gas is placed in a sealed container of fixed volume. As the temp of the confined gas increases from 10°c to 30°c, the internal pressure
A. Decreases
B. Increases
C. Remain the same
Does anyone know these answers?
Correct me if I'm wrong but from my knowledge:
5, 6, 10, 11, 12, 15, 16, 17, 18, 19, and 20 would be a covalent bond
7, and 8 would be a metallic bond
9, 13, and 14 would be an ionic bond
which amino acid has the greatest amount of negative charge at ph = 6.20?
Answer:
Amino acid alanine
Explanation:
because it is.
Draw the two enantiomers that are obtained upon bromination of (S)-3-methylhexane.
Radical bromination of (S)-3-methylhexane results in 3-bromo-3-methylhexane as the main byproduct, which is optically inactive. The branching hydrocarbon 3-methylhexane has two enantiomers. It belongs to the family of heptane isomers.
One of heptane's two structural isomers, 2,3-dimethylpentane, and this particular molecule both possess the chirality property. They are (R)-3 methylhexane and (S)-3 methylhexane, respectively. Bromomethane is the natural product. This is a substitution process because one of the hydrogen atoms in the methane has been swapped out for a bromine atom. Enantiomers are stereoisomers that cannot be superimposed mirror images of one another. Depending on how each stereocenter is set up, enantiomers are different. In terms of handedness, they can be compared to gloves for the right or left hand.
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An absorption measurement with a 1 cm path length yields a reading of 0.002 absorbance units with a noise of 0.0005 absorbance units and a mean noise reading of 0 for 5 scans averaged together. Assuming the noise for a single scan does not change if the path length is increased to 5 cm and the number of scans is increase to 65, what is the signal to noise of the new measurement. Remember signal averaging
Answer:
Assuming the noise remains constant, the total noise for the longer path length, 65 scans should be 0.0005 x 65 = 0.0325 absorbance units. The new reading should be 0.01 absorbance units. The signal to noise ratio (SNR) of the new measurement will be 0.01/0.0325 = 3.08.
Signal averaging decreases the magnitude of the residual noise and increases the SNR. The total noise decreases by the square root of the number of scans, in this case √65 = 8, so for 65 scans, the noise level is 8 times lower than for a single scan.
An experiment is performed to determine to determine the molar mass of a solid unknown monoprotic acid (HA) by titration with a standardized NaOH solution. A) What measurements must be made to determine the number of moles of NaOH used in the titration? B) Write a mathematical expression to be used in determining the number of moles used to reach the endpoint of the titration. C) How can you use the information in B) to determine the moles of acid, HA? D) To determine the molar mass of the acid what should be measured about the acid before the titration? E) Write the mathematical expression to calculate the molar mass of the acid. F) Draw the apparatus to be used in this titration indicating what is going to be in each part of the apparatus. G) If the original solid acid was not completely dry before the experiment, would the results be different? In which way? Explain. H) If the original procedure called for dissolving the acid in 25.0 mL , but 35.0 mL were accidentally used, how would the results be affected? Explain.
The number of moles of NaOH is calculated by multiplying the moles of KHP by the mole ratio of NaOH to KHP, which is found by the balanced chemical reaction previously discussed.
Why is it called titration?A titration is described as "the process of determining the amount of a substance A by adding calibrated increments of substance B, the titrant, with which it reacts until exact chemical equivalency is obtained (the equivalence point)" (Oxford Dictionary of Chemical Terms).
The moles of KHP are multiplied by the mole ratio of NaOH to KHP, which is determined by the balanced chemical reaction mentioned above, to determine the number of moles of NaOH. 3. To determine the molarity of the NaOH solution, divide the moles of NaOH by the amount of NaOH solution needed to reach the titration's endpoint, in this case, litres.
The formula is molarity (M) of the acid x volume (V) of the acid = molarity (M) of the base x volume (V) of the base when the titrant and analyte have a mole ratio of 1:1. The concentration of a solution, measured in moles of solute per litre of solution, is known as its molarity.
Ha has a 268-gram mass per mole in its molar form. Ha is not a recognised chemical symbol for an element.
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sample multiple choice question on quantum mechanical atomic model under analysis
sample questions on how ions are formed
Ions are formed by chemical interactions of accepting or loosing electrons.
What are ions?An ion is defined as an atom or a molecule which has a net electrical charge. There are 2 types of ions :1) cation 2) anion . The cation is the positively charged ion and anion is the negatively charged ion . As they are oppositely charged they attract each resulting in the formation of ionic bond.
Ions consisting of single atom are mono-atomic ions while which consists of two or more ions are called as poly-atomic ions . They are created by chemical interactions . They are very reactive in their gaseous state and rapidly react with oppositely charged ions resulting in neutral molecules.
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Predict the normal boiling point of hydrogen peroxide (H2O2) from the following data: ΔHºf, kJ/mol Sº, J/(mol • K) H2O2(ℓ) –187.8 110 H2O2(g) –136.3 233 Tb = Based on the estimated boiling point, is H2O2 a liquid or a gas at room temperature (25°C)? Why?
Choose one:
A liquid, because its estimated boiling point is less than 25°C.
A gas, because its estimated boiling point is less than 25°C.
A liquid, because its estimated boiling point is greater than 25°C.
A gas, because its estimated boiling point is greater than 25°C.
The correct option is: A liquid, because its estimated boiling point is greater than 25°C
What is boiling point?A liquid's boiling point is determined by the temperature at which its vapour pressure equals that of the gas above it. The temperature at which a liquid's vapour pressure equals one atmosphere is known as the normal boiling point of that liquid (760 torr).
When a substance's vapour pressure reaches parity with outside pressure, that point is known as its boiling point.
H₂O₂(l) ↔ H₂O₂(g)
ΔH⁰rxn = (ΔH⁰f, H₂O₂(g) - ΔH⁰f, H₂O₂(l))
or, ΔH⁰rxn = (-136.3-(-187.8))
or, ΔH⁰rxn = 51.5 KJ/mol
or, ΔH⁰rxn = (Δs⁰f, H₂O₂(g) - Δs⁰f, H₂O₂(l))
or, ΔH⁰rxn = (233 - 110)
or, ΔH⁰rxn = 123 J/mol.k
at the boiling point (Tb), ΔG⁰ = 0 (due to equilibrium)
As we know,
ΔG⁰ = ΔH⁰- TΔs⁰
or, 0 = 51.5*10^3 - (T*123)
or, T = boiling point of H₂O₂
or, T = 418.7 K
or, T = 418.7 - 273.15 K
or, T = 145.55 °C
As, boiling point of H₂O₂ is higher than room temperature (25°c). it is liquid.
Thus, a liquid, because its estimated boiling point is greater than 25°C.
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which of the following has two equatorial alkyl substituents in its most stable conformation?
A.) 1,1-dimethylcyclohexane
B.) cis-1,2-dimethylcylcohexane
C.) cis-1,3-diethylcylcohexane
D.) cis-1,4-diethylcylcohexane
E.) trans-1,3-diethylcylcohexane
B.) cis-1,2-dimethylcylcohexane has two equatorial alkyl substituents in its most stable conformation
In cyclohexane ring, the most stable conformation is the one that has the lowest energy. The ring can adopt different conformations, such as the chair or the boat, depending on the position of the substituents. The most stable conformation of cyclohexane ring is the one that has maximum number of Substituents in equatorial position and minimum number of substituents in axial positions. The equatorial positions are more stable than the axial positions because they are farther apart and less crowded.In option B, cis-1,2-dimethylcylcohexane, the methyl groups are in equatorial positions, which makes it the most stable conformation among the options given.
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The "alum" used in cooking is potassium aluminum sulfate hydrate, KAl(SO4)2·x H2O. To find the value of x, you can heat a sample of the compound to drive off all of the water and leave only KAl(SO4)2. Assume you heat 4.74 g of the hydrated compound and that the sample loses 2.16 g of water. What is the value of x?
The "alum" used in cooking is potassium aluminum sulfate hydrate, KAl(SO4)2·x H2O and the value of x calculated is 12.
What is meant by alum?Alum is a type of chemical compound, usually hydrated double sulfate salt of aluminum having general formula X Al ₂·12 H ₂O, where X is monovalent cation such as potassium or ammonium.
Given mass of KAl(SO₄)₂.XH₂O = 4.74 g
and mass of water = 2.16 g
So, mass of KAl(SO₄)₂ = 4.74 – 2.16 = 2.58 g
Molar mass of KAl(SO₄)₂ ;
= 39 + 27 + 2[32 + (4×26)]
Now, molar mass of KAl(SO₄)₂ = 258 g/mol
Molar mass of H₂O ;
= (2×1) + 16
Now, molar mass of H₂O = 18 g/mol
Hence, KAl(SO₄)₂ = 2.58 / 258 = 0.01
and H₂O = 2.16 / 18 = 0.12
KAl(SO₄)₂ = 0.01 / 0.01 = 1
H₂O = 0.12 / 0.01 = 12
The formula of the compound is obtained as KAl(SO₄)₂.12H₂O
Comparing KAl(SO₄)₂.12H₂O with KAl(SO₄)₂.XH₂O, value of X is 12.
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for the following reaction sequence, which molecule is expected as the major product?
The first reaction is an oxidation reaction, which converts molecule A to molecule C using hydrogen peroxide (H2O2) and hydroxide (OH-) as the oxidizing agents.
The second reaction is a further oxidation reaction, which converts molecule C to molecule D using H2O2 and OH- as the oxidizing agents. Therefore, molecule D is expected as the major product of the reaction sequence.
The oxidation of A to C involves the addition of oxygen atoms to the molecule. This process is catalyzed by the presence of hydrogen peroxide (H2O2) and hydroxide (OH-) ions, which act as the oxidizing agents. In the second reaction, the oxidation of C to D involves the further addition of oxygen atoms to the molecule. This process is also catalyzed by H2O2 and OH- ions, resulting in the formation of molecule D as the major product of the overall reaction sequence.
the complete question is : For the following reaction sequence, which molecule is expected as the major product?
[tex]$\ce{A + B - > [\ce{H2O2/OH-}] C - > [\ce{H2O2/OH-}] D}$[/tex]
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