To run a spectrophotometry experiment, begin by _________ the spectrophotometer and preparing the samples. Be sure to select the correct ________, then run a measurement on the _________ solution. Follow up by running measurements on _______solutions. Once data is collected, turn off the instrument, clean the area, and discard the samples.
Answer:
To run a spectrophotometry experiment, begin by warming up the spectrophotometer and preparing the samples. Be sure to select the correct wavelength, then run a measurement on the blank solution. Follow up by running measurements on sample solutions. Once data is collected, turn off the instrument, clean the area, and discard the samples.
Explanation:
The spectrophotometer is a device used in laboratories to carry out analysis in experiments that need to measure and compare the amount of light absorbed or transmitted between samples, regardless of whether the samples are transparent or opaque solid. The spectrophotometer can be single-beam and double-beam. Regardless of the nature of the beam, to perform a spectrophotometry experiment, you must start by heating the spectrophotometer and preparing the samples. Make sure to select the correct wavelength and perform a measurement on the blank solution. Follow up by performing measurements on sample solutions. Once the data is collected, turn off the instrument, clean the area and discard the samples.
Burning plants contributes to global warming because:
a) carbon dioxide is released during combustion
b) there are no trees to provide shade
c) much oxygen is used up during combustion
d) the sun beats on the bare soil.
Answer:carbon dioxide is released during combustion
PLEASE HELP ME ITS DUE IN 25 MINUTES True or false iron and nickel are less dense than silicates ?
hydrogen gas is collected by downward displacement of water why
Explanation:
Hydrogen is collected by downward displacement of water as it is less denser than water. Hence it comes out at the surface of water . It is insoluble in water so it does not dissolve in water. ... So, it is impossible to collect hydrogen gas in air medium.22-O
A flexible container is filled with He(g) to a volume of V1 at a temperature of 150K. The container is then heated at constant pressure to a temperature of 300K. What is the final volume of the container?
a. V1/3b. V1/2c. V1d. 2V1
Answer:
a but it might also be c
Explanation:
i d k what this is
Answer:
2V1
Explanation:
A 1,900-m3 water tower has been cleaned with a chlorine solution. The vapors of chlorine in the tower exceed allowable concentrations for the work crew to enter and finish repairs. If the chlorine concentration is 15 mg/m3 and the allowable concentration is 0.0015 mg/L, how long must the workers vent the tank with clean air flowing at 2.35 m3/s
Answer:
t = 1862 s
Explanation:
To do this, we need first to determine the theorical detention time, which can be determined with the following expression:
t₀ = ∀/Q (1)
Where:
t₀: detention time
∀: Volume of the fluid in the reactor
Q: Flow rate in the reactor
With this time, we must use the following expression to determine the time that the workers will take to vent the tank:
C = C₀ e^(-t/t₀) (2)
From here, we must solve for time t, and the expression will be:
t = ln(C₀/C) * t₀ (3)
Now that we know the expression to use, let's solve for t. Using (1) to determine the detention time, ∀ is 1900 m³, and Q is 2.35 m³/s so:
t₀ = 1900 / 2.35 = 808.51 s
Now, let's solve for the time t. C will be 0.0015 mg/L (or 1.5 mg/m³ cause in 1 m³ we have 1000 L) and C₀ 15 mg/m³:
t = ln(15/1.5) * 808.51
t = 1861.66 s or simply 1862 sHope this helps
Explain how it's possible that warm temperatures can cause more snow to happen.
An ideal gas that is confined in piston-cylinder assembly (i.e., closed system) goes from an initial state of 1 bar at 300 K to a final state of 3 bar at 300 K by the following two-step process.
Process Path.
(Step 1) Heating at constant volume, and then
( Step 2) Cooling by holding the pressure constant.
Required:
a. Determine the initial and final molar mass.
b. Illustrate the two paths on a pressure-volume diagram. Clearly label the initial and final states, process steps and the direction of each step in the diagram.
Answer:
Explanation:
From the given information;
Using ideal gas equation:
pV = nRT
when n = 1 mol
[tex]V = \dfrac{RT}{p}[/tex]
Initial molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{1 \ bar}[/tex]
Initial molar volume = 2494.2 L.mol⁻¹
Final molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{3 \ bar}[/tex]
Final molar volume = 831.4 L.mol⁻¹
1. Fill in the blanks. Example: A nitrogen atom takes on a 3- charge when it forms an anion and becomes nitride. a. A magnesium atom takes on a ___ charge when it forms a(an) ____ion and becomes . b. A chlorine atom takes on a ___ charge when it forms a(an) ____ion and becomes . c. An oxygen atom takes on a ___ charge when it forms a(an) ____ion and becomes . d. A potassium atom takes on a ___ charge when it forms a(an) ____ion and becomes .
Answer: a. +2, cation and magnesium ion .
b. -1, anion, chloride
c. -2, anion, oxide
d. +1. cation , potassium ion
Explanation:
When an atom accepts an electron negative charge is created on atom and is called as anion.
When atom loses an electron positive charge is created on atom and is called as cation.
Magnesium (Mg) with atomic number of 12 has electronic configuration of 2,8,2 and thus it can lose 2 electrons to form [tex]Mg^{2+}[/tex] cation and becomes magnesium ion.
Chlorine (Cl) with atomic number of 17 has electronic configuration of 2,8,7 and thus it can gain 1 electron to form [tex]Cl^{-}[/tex] anion and becomes chloride.
Oxygen (O) with atomic number of 8 has electronic configuration of 2,6 and thus it can gain 2 electrons to form [tex]O^{2-}[/tex] anion and becomes oxide.
Potassium (K) with atomic number of 19 has electronic configuration of 2,8,8,1 and thus it can lose 1 electron to form [tex]K^{+}[/tex] cation and becomes potassium ion.
The chemical equation below shows the reaction of magnesium and oxygen which combine to form magnesium oxide.
Mg + O = MgO
In this equation, magnesium and oxygen are the _____
•reactants
•products
Help plz
Scientists Believe that:
A. The continents are shifting
B. The world was once one big mass
C. The center of the earth is made of iron and nickel
D. All of the above
E. None of the above
Answer: D
Explanation: Today, we know that the continents rest on massive slabs of rock called tectonic plates. They are constantly in movement and they are responsible for several natural disasters. Approximetly 335 million years ago, during the late Paleozoic and early Mesozoic eras, the world was one big mass, called Pangea, which eventually would start to break apart about 175 million years ago. At the center of the Earth is the core, which has two parts. The solid, inner core of iron has a radius of about 760 miles (about 1,220 km), according to NASA. It is surrounded by a liquid, outer core composed of a nickel-iron alloy.
I hope it helps
Answer:
the answer is D
Explanation:
It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). Write an equation that shows the dehydration of manganese(II) sulfate pentahydrate . Use an asterisk to enter the dot.
Answer:
MnSO4.5H2O(s) ---------> MnSO4(s) + 5H2O(g)
Explanation:
The dehydration of a hydrate implies that the water of crystallization is lost. Water of crystallization is included in the crystal structure as it is formed and is incorporated into the structure of the compound.
Now the equation for the dehydration of manganese(II) sulfate pentahydrate is;
MnSO4.5H2O(s) ---------> MnSO4(s) + 5H2O(g)
The MnSO4 is now said to be anhydrous.
PLEASE HELP!!
15POINTS!!! And brainliest
Answer: a. 3.36 L
b. 33.2 g
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Standard condition of temperature (STP) is 273 K and atmospheric pressure is 1 atm respectively.
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of} Fe_2O_3=\frac{16.0g}{159.69g/mol}=0.1mole[/tex]
[tex]3O_2(g)+4Fe(s)\rightarrow 2Fe_2O_3(s)[/tex]
a. 2 moles of [tex]Fe_2O_3[/tex] are produced by = [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex]
Thus 0.1 moles of [tex]Fe_2O_3[tex] are produced by =[tex]\frac{67.2}{2}\times 0.1=3.36L[/tex] of [tex]O_2[/tex]
b. [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex] react with = [tex]4\times 55.8=223.2g[/tex] of iron
Thus 10.0 L of [tex]O_2[/tex] react with = [tex]\frac{223.2}{67.2}\times 10=33.2g[/tex] of iron
A balloon of hydrogen is subjected to vacuum. The initial pressure and volume of hydrogen is 0.95 atm and 0.55 L. Calculate the final pressure if the final volume is 1.22 L?
Answer:
0.43 atm
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 0.95 atm
Initial volume (V₁) = 0.55 L
Final volume (V₂) = 1.22 L
Final pressure (P₂) =?
The final pressure of the gas can be obtained by using the Boyle's law equation as follow:
P₁V₁ = P₂V₂
0.95 × 0.55 = P₂ × 1.22
0.5225 = P₂ × 1.22
Divide both side by 1.22
P₂ = 0.5225 / 1.22
P₂ = 0.43 atm
Therefore, the final pressure of the gas is 0.43 atm
The final pressure of the gas is 0.43 atm.
What is pressure?Pressure is the process of force exerted perpendicular to any surface.
Given, the Initial pressure (P₁) is 0.95 atm
The initial volume (V₁) is 0.55 L
The final volume (V₂) is 1.22 L
To find the final pressure (P₂)
By the Boyle's Law
[tex]\rm P_1V_2= P_2V_2[/tex]
[tex]\rm 0.95\times 0.55 = P_2\times1.22\\\\0.5225 = P_2 \times 1.22\\\\Divided\;both \;side\;by\;1.22\\\\P_2=\dfrac{0.5225}{1.22} = 0.43 atm.[/tex]
Thus, the final pressure of the gas is 0.43 atm.
Learn more about pressure, here:
https://brainly.com/question/356585
In the compound aluminum oxide, which is the cation?
Answer:
-Aluminum Oxide: The cation is Al3+ and the anion is O2-. The sum of the charges for aluminum oxide is 2(3+) + 3(2-) = 0. Thus, the formula is Al2O3. An ionic compound is named using the name of the cation followed by the name of the anion, eliminating the word ion from each.
Explanation:
A 14 year old girl is small in stature and appears younger than her age. She has not started menstruating, and her parents are concerned that she is not growing taller nor entering puberty. She has frequent headaches, and is having difficulty seeing the board at school, even though she sits near the front of the room. She feels cold, even when the room is warm, and she is often constipated. Her parents are concerned. She is in the 30th percentile for height and weight, significantly below her peers.
Required:
What hormones are of LEAST concern in this person?
a. insulin
b. GH
c. GnRH
d. TSH
Answer:
A.
B.
Explanation:
The vapor pressure of liquid pentane, C5H12, is 40.0 mm Hg at 244 K. A sample of C5H12 is placed in a closed, evacuated container of constant volume at a temperature of 409 K. It is found that all of the C5H12 is in the vapor phase and that the pressure is 62.0 mm Hg. If the temperature in the container is reduced to 244 K, which of the following statements are correct?
a. No condensation will occur.
b. The pressure in the container will be 100. mm Hg.
c. Only pentane vapor will be present.
d. Some of the vapor initially present will condense.
e. Liquid pentane will be present.
Answer:
b. The pressure in the container will be 100mm Hg.
d. Some of vapor initially present will condense.
Explanation:
The vapor pressure of liquid Pantene rises when there is container where evacuation of water molecules is restricted. The pressure inside the container rises to 100 mm Hg and then liquid molecules start condensing. These molecule form vapors.
How does fertilizer benefit the daily lives of people?
Answer:
Fertilizers play an important role in providing crops with the nutrients they need to grow and be harvested for nutritious food. Fertilizers help deliver enough food to feed the world's population. ...
For example, micronutrients such as zinc are important to human nutrition, especially children.
Explanation:
Hope it is helpful.....
The bond order for a double bond is
Answer:
B.Two
Explanation:
One mole of hydrogen is equal to____
What is the coefficient of iron(lll) carbonate?
Fe(NO3)3 + (NH4)2CO3
? Fe2(CO3)3 + NH4NO3
Someone please help me I’m so stuck I cannot find the empty ones that were not filled in :(. I’m really confused
Answer:
Positive charges: 2
Negative charges: 1
Overall charge: +1
Explanation:
In Diagram B we have the chemical element Helium (He). You can see in the Periodic Table that He has an atomic number of 2 and an atomic mass of approximately 4.
The atomic number is equal to the number of protons, so He has 2 protons. The protons are the positive charges in the atom, so the number of positive charges is 2. That is invariable, if the number of protons - or the atomic number - of an atom changes, it changes its identity.
In the drawing, we can see that the nucleus is composed of 2 protons (2 'p' particles) and 2 neutrons (2 'n' particles). The atomic mass is calculated as the number of protons and neutrons, so 2 protons+ 2 neutrons = 4.
The surrounding particle with an 'e' is an electron. So, we have 1 electron. Electrons are negative charges, so the number of negative charges is 1.
Now, we can calculate the overall charge. We add the positive charges (protons) and negative charges (electrons). Each proton has a +1 charge, whereas each electron has a -1 charge. Finally, we perform the addition:
Overall charge= (number of protons x charge) + (number of electrons x charge) = (2 x (+1)) + (1 x (-1)) = (+2) + (-1) = +1
How many zinc atoms are contained in 3.75 moles of zinc?
2.26 × 10²⁴ atoms Zn
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.75 mol Zn (Zinc)
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 3.75 \ mol \ Zn(\frac{6.022 \cdot 10^{23} \ atoms \ Zn}{1 \ mol \ Zn})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 2.25825 \cdot 10^{24} \ atoms \ Zn[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.25825 × 10²⁴ atoms Zn ≈ 2.26 × 10²⁴ atoms Zn
Why are there elements on the bottom of the periodic table? What’s the name of this group of elements?
Answer
The lanthanides and actinides are separated from the rest of the periodic table, usually appearing as separate rows at the bottom. The reason for this placement has to do with the electron configurations of these elements
Explanation:
IUPAC name for c2h2cl2?
Answer:
okay that is cool
Explanation:
Answer:
I hope it helps u! :)
Explanation:
A metal ion (X) with a charge of 4+ is attracted to non metal ion (Z) with a charge of 3-. Which of these formulas represents the resulting compound? I need answers asap please
Answer: [tex]X_3Z_4[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here metal X is having an oxidation state of +4 called as [tex]X^{4+}[/tex] cation and [tex]Z^{3-}[/tex] is an anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]X_3Z_4[/tex]
[tex]X_3Z_4[/tex] is the formula of the resulting compound.
A 75.0 sample of a natural product isolated from alfalfa hay was dissolved in water to make 100.0 mL of solution. The solution did not conduct electricity and has an osmotic pressure of 0.246 atm at 27.0c. What is the molar mass of this compound
Answer:
Sorry i dont know
Answer:
What is the vapor pressure of an aqueous solution that has a solute mol fraction of c = 0.100? The vapor pressure of water is 25.756 mm Hg at 25°C.
12) The vapor pressure of an aqueous solution is found to be 24.9 mm Hg at 25°C. What is the mole fraction of solute in this solution? The vapor pressure of water is 25.756 mm Hg at 25°C.
9) Determine the molarity of an aspirin solution that produces an osmotic pressure of 0.0555 atm at 25°C (i = 1).
10) A saline solution is administered intravenously to patients who cannot take fluid orally and are in danger of dehydration. The osmotic pressure of this solution must match that of blood to prevent hemolysis or crenation of blood cells. What mass of sodium chloride (58.44 g/mol) is needed to produce 100.0 mL of saline solution with an osmotic pressure of 7.83 atm at a body temper
Explanation:
A compound is 22.5% nitrogen and 77.5% oxygen, What is the empirical formula of
this compound?
Answer:
[tex]NO_3[/tex]
Explanation:
Hello!
In this case, since percent compositions are used to set up empirical formulas when assuming those percentages are masses, we can fist compute the moles of nitrogen and oxygen in the compound as shown below:
[tex]n_N=22.5g/14.01g/mol=1.61mol\\\\n_O=77.5g/16.00g/mol=4.84mol[/tex]
Now, we divide by the fewest moles to compute the subscripts:
[tex]N=\frac{1.61}{1.61} =1\\\\O=\frac{4.84}{1.61} =3[/tex]
Thus, the empirical formula turns out:
[tex]NO_3[/tex]
Best regards!
Scientist use capital letters (H) and lowercase letters (h) to represent genes. What type
of gene is represented by a capital letter?
Expressive
O Regressive
O Dominant
Recessive
Previous
Next >
Dividend
Divisor
Quotient/ Remainder
SAGOT
75
21
16.) 54
17.) 108
18.) 380
19.) 633
20.) 648
27
76
57
32
Solo
nihanda ni:
NNA MARIE S. CARAIT
borrinoloticon
Answer:
Dividend Divisor Quotient/ Remainder SAGOT 75 21 16.) 54 17.) 108 18.) 380 19.) 633 20.) 648 27 76 57 32. Solo nihanda ni: NNA MARIE S.
Explanation: