Solution :
The reasons for the melting point determines :
the assignment of the sample's purityidentification of the unknown samplethe conversion of solid sample to the liquid completelyIn order to prepare the sample in the capillary tube for determining its melting point, we tap the tube gently into the sample with the open end of tube down. We then continue tapping the tube till the sample is couple of millimeters high.
Then the other close end of tube down, we tap the sample down again slowly or then dropping the tube into a longer tube so as to move down the sample faster.
adaptive features of aquatic plants
what changes chemical energy to something you can use
based on the law of conservation of energy its it atoms hold by strong chemical bonds
Determine if the following two structures are
identical, isomers, or unrelated?
A
B
С
identical
isomers
unrelated
Answer:
its C
Explanation:
The skeletal structure shows the outline of the compound with lines and bonds. Both the structures are unrelated. Thus, option C is correct.
What are isomers?Isomers are structures with identical molecular structures but differ in the skeletal or molecular representation. They also have varied properties as compared to the parent structure.
Identical compounds are structures that have the same atoms and are arranged with the same spatial design and orientation. The number of atoms and the spatial arrangement of the two compounds is different.
Therefore, the two compounds are unrelated.
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What does synthesis gas (water gas) consist of?
Answer:
ch4+h2o----725°-->co+2h2
The nucleus of an atom stays together only because the repulsive forces, called
forces, are overcome by
even stronger attractive forces.
fusion
nuclear
electrostatic
Answer:
Electrostatic
Explanation:
The forces that are overcome are the repulsive electrostatic forces between the protons (all charged positively).
If you began a reaction with the following ions in solution, what would be the net ionic equation?
Na+, PO43–, Fe2+, and NO3–
Answer:
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
Explanation:
Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).
Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
A triangle has one angle that measures 81° and one that measures 37° what is the measure of a third angle
2KCIO3 -2KCL + 302
Use the balanced chemical equation to solve the following problems. Show all work and answer with the correct units and significant figures.
a. How many moles of oxygen are produced if 4 moles of potassium chlorate decomposes?
b. If 4.5 moles of potassium chloride are produced, how many molecules of oxygen gas are also produced?
c. If 5.0 g of potassium chlorate decomposes, how many grams of potassium chloride are produced?
Answer:
a. 6 moles of O₂
b. 4.06×10²⁴ molecules of O₂
c. 3.04 g of KCl
Explanation:
Reaction of decomposition is:
2KClO₃ → 2KCl + 3O₂
a. See stoichiometry value
2 moles of potassium chlorate can decompose to 2 moles of potassium chloride and 3 moles of oxygen. Ratio is 2:3
If 2 moles of KClO₃ can decompose to 3 moles of O₂
Then 4 moles, may decompose to (4 . 3)/2 = 6 moles of O₂
b. In this case, the stoichiometry is the same.
Per 2 moles of KClO₃, I produce 2 moles of KCl
Then, 4.5 moles of KCl, were produced by 4.5 moles of KClO₃
We apply, the last relation:
(4.5 . 3) /2 = 6.75 moles of O₂ are also produced.
How many molecules are in 6.75 moles?
6.75 mol . 6.02×10²³ molecules/mol = 4.06×10²⁴ molecules of O₂
c. First of all, we convert the mass to moles:
5g . 1mol /122.55g = 0.0408 moles of salt
As ratio is 2:2, 0.0408 moles of salt, decompose to 0.0408 moles of KCl
We convert the moles to mass: 0.0408 mol . 74.55g /mol = 3.04g
The equation below illustrates the process of
Pb2+ (aq) + 11- (aq) → Pblu (s)
a) dissolution
b) precipitation
c) decomposition
Answer:
The correct answer is - b) precipitation.
Explanation:
In the given question the lead ion in an aqueous solution is mixed with the Leutium ion in an aqueous solution and forms an insoluble or solid salt. This type of reaction is referred to as precipitation reactions in chemistry.
Such reactions are helpful in determining if a particular ion is present in the solution or not.
Pb2+ (aq) + lu- (aq) → Pblu (s)
State the coefficient required to correctly balance the following chemical equation:
__KCI + __Fe —-> __FeCI2+ __K
Answer:
2KCl+Fe---->FeCl2+2K
Explanation:
You can observe that the no.of atoms in reactant side is equal to that of products side of each element.
Please help me, I can't figure this out. You have a 450.0 mL balloon filled with 0.0184 moles of Helium gas. The volume of the balloon will change, but the pressure of the gas inside will always match the 1.00 atm pressure outside. If the balloon is kept at a constant 25oC, how many moles of gas must you remove to shrink the balloon down to 200.0 mL?
Answer and Explanation:
V1/n1 = V2/n2
450.0 mL / 0.0184 mol = 200.0 mL / n2
n2 = 8.17X10^-3 mol
moles removed = 0.0184-8.17X10^-3 = 0.0102 mols removed, I think I'm right but I'm not 100% sure..
According to Avogadro's law, 0.008 moles of gas must be removed to shrink balloon to 200 ml.
What is Avogadro's law?Avogadro's law is a gas law which states that the total number of atoms or molecules has a direct proportion to the volume occupied by a gas at a constant temperature and pressure.
It is closely related to ideal gas equation as it links temperature, pressure, volume and the amount of substance.It is given as, V∝n,
The straight line graph of volume versus moles is a straight line passing through the origin which implies that zero moles of gas occupy zero volume.
Here, the number of moles is calculated as, V₁/n₁=V₂/n₂
Therefore on substitution, n₂=0.0184×200/450=0.008 moles.
Thus,0.008 moles are required to shrink the balloon to 200 ml.
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A burning match will burn more vigorously in pure oxygen than in air because _________ . Select one: a. oxygen is a catalyst for combustion b. nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion c. oxygen is a product of combustion d. nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature e. oxygen is a reactant in combustion and pure oxygen increases the reactant concentration
Answer:
e. oxygen is a reactant in combustion and pure oxygen increases the reactant concentration
Explanation:
The reaction of a burning match is combustion. In this combustion, the organic components of the match (such as cellulose, C₆H₁₀O₅) react with oxygen, producing water and carbon dioxide:
C₆H₁₀O₅(s) + 6O₂(g) → 5H₂O(g) + 6CO₂(g)Seeing as oxygen is a reactant and not a catalyst nor product, and that nitrogen plays no part in the reaction, the only correct answer is option e.
What will happen if HI is removed from a reaction vessel containing this
reaction at equilibrium?
H2+ 12 22H1
A. The reaction will slow down.
B. There will be no effect.
C. The rate of the forward reaction will increase.
D. The rate of the backward reaction will increase.
SUBMIT
Answer:
C I think
Explanation:
There will be no effect if HI is removed from a reaction vessel containing this reaction at equilibrium. When HI remove, concentration of all three component is change and reach a new equilibrium stage.
H2 + I2 ⇄ 2HI
So, B is correct option.
What is equilibrium?The stage in reversible reaction at which rate of forward reaction is equal to rate of backward reaction is equal is called an equilibrium.
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What BEST describes the relation of a new population to an increase in the amount of space it occupies? a - The population will die out
b - The population will remain constant
c - The population will grow exponentially
which statement describes the process of budding
Answer:
Budding, in biology, a form of asexual reproduction in which a new individual develops from some generative anatomical point of the parent organism. ... The initial protuberance of proliferating cytoplasm or cells, the bud, eventually develops into an organism duplicating the parent.
Explanation: im not sure if this will help because you didnt give any statements.
Answer: Cell division with mitosis causes new individuals to develop on a parent.
Explanation: did the test A.P.E.X. hope this helps <3
Lewis dot diagram for the Cs1+ ion
Answer:
[tex]Cs^+[/tex]
Explanation:
Cesium Lewis dot structure would look like this:
·Cs, because it only has one valence electron. But, since it has a plus, that means we lost an electron. So, we have to get rid of the dot and you have:
[tex]Cs^+[/tex]
what is Determine the mass of 2.40 moles of CoH12
Answer:
mass of CO 2 = M r x number of moles of CO 2 = 44.0 × 0.010 = 0.44 g
Explanation:
If 7.0 moles of HCl is added to enough iron that the HCl is completely used up, how many
moles of hydrogen gas will be produced?
Answer:
3.5 mol
Explanation:
Step 1: Given data
Moles of HCl: 7.0 mol
Step 2: Write the balanced equation
Fe(s) + 2 HCl(aq) ⇒ FeCl₂(aq) + H₂(g)
Step 3: Calculate the moles of H₂ gas produced from 7.0 moles of HCl
According to the balanced equation, the molar ratio of HCl to H₂ is 2:1.
7.0 mol HCl × 1 mol H₂/2 mol HCl = 3.5 mol H₂
What is the main gas in our atmosphere?
Answer:
Nitrogen
Explanation:
Answer:
Yes, its nitrogen. I wrote my answer earlier in the wrong spot.
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.
One of the following is not a physical property of iron.
Mark only one oval.
malleability
magnetism
rusting
color
Answer:
Rusting
Explanation:
Rusting is oxidizing iron, which would be a chemical property.
I need help plzzzzzz
Answer:
it is 25%
Explanation:
Answering so you can give the other person brainliest :D have a good day
Put the following type of radiations in order of increasing energy: red, radio, UV, infrared, blue, and x-ray
Answer: The order of increasing energy is: radio < infrared < red < blue < UV < x rays
Explanation:
Electromagnetic wave is defined as the wave which is associated with both electrical and magnetic component associated with them.
The electromagnetic radiations consist of gamma rays , X rays , Ultraviolet , Visible , Infra red , microwaves and radio waves arranged in order of decreasing frequency and increasing wavelengths. The visible region consists of violet , indigo , blue , green , yellow, orange and red lights in order of decreasing frequency or increasing wavelength
The relationship between energy and frequency of the wave follows the equation:
[tex]E=h\times \nu[/tex]
where,
[tex]\nu[/tex] = frequency of the wave
E = energy of wave
From the above relation, it is visible that energy and frequency follow direct relation. For increase in value of frequency, energy increases and vice-versa.
Thus the order of increasing energy is: radio < infrared < red < blue < UV < x rays
can someone help me with this will mark brainliest
Answer:
3
Explanation:
4. What is the specific heat of a substance if 5800 joules is
released in a 250 gram sample that will cool the substance from
60 degrees to 45 degrees?
Answer: 23.2
Explanation:
Pls help me over here
Answer:
1 and the element is hydrogen (there is an exception for the octet rule for the element hydrogen) hope this helps
Explanation:
Which is a form of kinetic energy?
A. gravitational energy
B. chemical energy
C. electrical energy
D. sound energy
Ammonia can be made by reaction of water with magnesium nitride as shown by the following unbalanced equation: Mg3N2(s) + H2O(l) Mg(OH)2(s) + NH3(g) If this process is 71% efficient, what mass of ammonia can be prepared from 24.5 kg magnesium nitride?
The mass of ammonia prepared from 24.5 kg magnesium nitride, according to the reaction Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH₃(g), knowing that the process is 71% efficient is 5.87 kg.
The balanced reaction of production of ammonia is:
Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH₃(g) (1)
First, let's find the number of moles of magnesium nitride
[tex] n_{Mg_{3}N_{2}} = \frac{m_{Mg_{3}N_{2}}}{M_{Mg_{3}N_{2}}} [/tex] (2)
Where:
[tex]m_{Mg_{3}N_{2}}[/tex]: is the mass of Mg₃N₂ = 24.5 kg
[tex]M_{Mg_{3}N_{2}}[/tex]: is the molar mass of Mg₃N₂ = 100.9494 g/mol
The number of moles is (eq 2):
[tex] n_{Mg_{3}N_{2}} = \frac{m_{Mg_{3}N_{2}}}{M_{Mg_{3}N_{2}}} = \frac{24500 g}{100.9494 g/mol} = 242.70 \:moles [/tex]
We can calculate the mass of ammonia prepared, knowing that 1 mol of Mg₃N₂ reacts with 6 moles of H₂O to produce 3 moles of Mg(OH)₂ and 2 moles of NH₃ (reaction 1).
[tex]n_{NH_{3}} = \frac{2\: moles\: NH_{3}}{1\: mol\: Mg_{3}N_{2}}*n_{Mg_{3}N_{2} = \frac{2\: moles\: NH_{3}}{1\: mol\: Mg_{3}N_{2}}*242.70 \:moles \:Mg_{3}N_{2} = 485.4 \:moles[/tex]
Then, the mass of NH₃ is:
[tex] m_{NH_{3}} = n_{NH_{3}}*M_{NH_{3}} = 485.4 \:moles*17.031 g/mol = 8266.8 g = 8.27 kg [/tex]
Since the process is 71% efficient, the mass that can be prepared is:
[tex] m = 8.27 kg*0.71 = 5.87 kg [/tex]
Therefore, the mass of ammonia that can be prepared is 5.87 kg.
I hope it helps you!
Answer all the following questions by putting a circle around a letter A.B.C or D
1. Air contains about
A. 3% carbon (IV) oxide.
B. 4%noble gases.
C. 21%oxygen
D. 69% nitrogen
Answer:
C. 21%oxygen
Explanation:
Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.
A student mixes 5.00 mL of 0.0020 M Fe(NO3)3 with 3.00 mL of 0.0020 M KSCN solution and 2.00 mL water at a certain temperature. He places a sample of the resulting solution in a spectrometer, and measures the transmittance as 23% at 447 nm. What are the initial concentrations of [Fe3 ] and [SCN-]
Answer:
[Fe⁺³] = 0.0010 M
[SCN⁻] = 0.0006 M
Explanation:
First we calculate how many moles of Fe⁺³ and SCN⁻ were added, using the given volumes and concentrations:
Fe⁺³ ⇒ 5.00 mL * 0.0020 M = 0.010 mmol Fe⁺³SCN⁻ ⇒ 3.00 mL * 0.0020 M = 0.006 mmol SCN⁻Now we can calculate the initial concentrations, after calculating the new volume of the solution:
New volume = 5.00 mL + 3.00 mL + 2.00 mL = 10.00 mL[Fe⁺³] = 0.010 mmol / 10.00 mL = 0.0010 M[SCN⁻] = 0.006 mmol / 10.00 mL = 0.0006 M3. Define the term zwitterion. Draw the structure of alanine and explain why this molecule is a
zwitterion in certain conditions.
Answer:
A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid.
Explanation:
A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid. The net charge on a zwitterion is zero since it has equal number of positive and negative charges.
Alanine, is a monoamino monocarboxylica acid that is diprotic when fully protonated. The carboxylic acid group, COOH and the amino group, NH₃⁺, are able to produce one proton each. At a pH equal to the isoelectric point of alanine, it exists mainly in the zwitterionic form with the α-amino group protonated as NH₃⁺ and the α-carboxyl group deprotonated as COO⁻ . This is because at the isoelectric point of alanine (6.0), pI is greater than the acid dissociation constant, pKa of the α-carboxyl group whereas, pI is less than the acid dissociation constant, pKa of the α-amino group, so the two groups are negatively and positively charged respectively.