Answer:
Mass ratio:
a. Approximately [tex]51.2\%[/tex].
b. Approximately [tex]35.3\%[/tex].
c. Approximately [tex]43.2\%[/tex].
Explanation:
Look up the relative atomic mass of each element on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm S[/tex]: [tex]32.06[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm Li[/tex]: [tex]6.94[/tex].[tex]\rm C[/tex]: [tex]12.011[/tex].[tex]\rm Al[/tex]: [tex]26.982[/tex].[tex]\rm N[/tex]: [tex]14.007[/tex].For example, the relative atomic mass of [tex]\rm Al[/tex] is [tex]26.982[/tex]. Hence, the mass of one mole of [tex]\rm Al\![/tex] atoms would be (approximately) [tex]26.982\; \rm g[/tex].
Calculate the formula mass of [tex]\rm H_2O[/tex]:
[tex]\begin{aligned} & M({\rm H_2O}) \\ &= 2 \times 1.008 + 15.999 \\ &= 18.015\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
Calculate the formula mass for each of the hydrates:
[tex]\begin{aligned}& M({\rm MgSO_4 \cdot {7\, H_2O}}) \\ &= 24.305 + 32.06 + 4 \times 15.999 \\ & \quad\quad + 7 \times (2 \times 1.008 + 15.999) \\ &= 246.466\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
[tex]\begin{aligned}& M({\rm LiC_2H_3O_2 \cdot {2\, H_2O}}) \\ &= 6.94 + 2 \times 12.011 + 3 \times 1.008 + 2 \times 15.999 \\ & \quad\quad + 2 \times (2 \times 1.008 + 15.999) \\ &= 102.014\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
[tex]\begin{aligned}& M({\rm Al(NO_3)_3 \cdot {9\, H_2O}}) \\ &= 26.982 + 3 \times (14.007 + 3 \time 15.999) \\ &\quad \quad + 9 \times (2 \times 1.008 + 15.999) \\ &= 375.129\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
The mass of [tex]1\; \rm mol[/tex] of [tex]{\rm MgSO_4 \cdot {7\, H_2O}}[/tex] formula units is [tex]246.466\; \rm g[/tex].
There are seven mole of [tex]\rm H_2O[/tex] formula units in that many [tex]{\rm MgSO_4 \cdot {7\, H_2O}}[/tex] formula units. The mass of that [tex]7\; \rm mol[/tex] of [tex]\rm H_2O\![/tex] formula units would be [tex]7 \; \rm mol \times 18.015\; \rm g \cdot mol^{-1} = 127.105\; \rm g[/tex].
Hence, the percentage mass of [tex]\rm H_2O[/tex] in [tex]{\rm MgSO_4 \cdot {7\, H_2O}}[/tex] would be:
[tex]\begin{aligned}\frac{127.015\; \rm g}{246.466\; \rm g} \approx 51.2\%\end{aligned}[/tex].
Similarly:
Mass of [tex]1\;\rm mol[/tex] of [tex]\rm LiC_2H_3O_2 \cdot {2\, H_2O}[/tex] formula units: [tex]102.014\; \rm g[/tex].Mass of the [tex]2\; \rm mol[/tex] of [tex]\rm H_2O[/tex] in that [tex]1\;\rm mol[/tex] of [tex]\rm LiC_2H_3O_2 \cdot {2\, H_2O}[/tex] formula units: [tex]2 \; \rm mol \times 18.015\; \rm g \cdot mol^{-1} = 36.030\; \rm g[/tex].Percentage mass of [tex]\rm H_2O[/tex] in [tex]\rm LiC_2H_3O_2 \cdot {2\, H_2O}[/tex]: [tex]\begin{aligned}\frac{36.030\; \rm g}{102.014\; \rm g} \approx 35.3\%\end{aligned}[/tex].Mass of [tex]1\;\rm mol[/tex] of [tex]\rm Al(NO_3)_3 \cdot {9\, H_2O}[/tex] formula units: [tex]375.129\; \rm g[/tex].Mass of the [tex]9\; \rm mol[/tex] of [tex]\rm H_2O[/tex] in that [tex]1\;\rm mol[/tex] of [tex]\rm Al(NO_3)_3 \cdot {9\, H_2O}[/tex] formula units: [tex]9 \; \rm mol \times 18.015\; \rm g \cdot mol^{-1} = 162.135\; \rm g[/tex].Percentage mass of [tex]\rm H_2O[/tex] in [tex]\rm Al(NO_3)_3 \cdot {9\, H_2O}[/tex]: [tex]\begin{aligned}\frac{162.135\; \rm g}{375.129\; \rm g} \approx 43.2\%\end{aligned}[/tex].what is the wave speed if the wave length is 8 and the frequency is 20
Answer:
160m/s
Explanation:
To find V Use the following formula V= F*W
V= Velocity F= Frequency W= Wavelength
V=20*8
=160m/s
Gases Test
Chemistry
Answer:
6.64 l is the answer.......
PLSSSSSSSS ANSWERRRRR
How would you prepare a 1 L solution of 3 M MgO?
Answer: 175.35g
Explanation: A 3 M solution has 3 moles of solute per litre.
The mass of one mole of NaCl equals the MW of NaCl MW = 35.45 + 23 =58.45 g/mol
The mass of 3 moles is 58.45 g/mol ×3 mol=175.35 g NaCl or 200 g rounded to one sigfig.
Mikala pours a tablespoon of salt into a beaker of water. Diffusion will cause the salt molecules to dissolve in the molecules of water. How could Mikala increase the diffusion rate of the salt molecules?
A. Mikala could remove all sources of light from the beaker.
B. Mikala could slowly pour more water into the beaker.
C. Mikala could decrease the temperature of the solution.
D. Mikala could increase the temperature of the solution.
Iron + --> iron sulphate + copper What is missing ? Iron sulphate Copper sulphate Copper oxideIron oxide
Answer:
Copper Sulphate is missing
true or false. a short circuit cannot cause a fire
Answer:
false
Explanation:
Answer:
FalseExplanation:
A short circuit can cause a spark or fire.
what is the name of the part of a cell that allows molecules in in, such as glucose and oxygen?
Answer:
A plasma membrane is permeable to specific molecules that a cell needs. Transport proteins in the cell membrane allow for selective passage of specific molecules from the external environment. Each transport protein is specific to a certian molecule (indicated by matching colors).
3 – Simple Diffusion Across the Cell (Plasma) Membrane: The structure of the lipid bilayer allows small, uncharged substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass through the cell membrane, down their concentration gradient, by simple diffusion.
Or Cell Membrane
Explanation:
Hope This HElp??
Please MArk Me Brainly!!
PLEASE WILL MARK BRAINLYIST
Answer:
3 i am pretty sure make me brainy i gust
Explanation:
Sea water contains 2% salt (NaCl) by weight. Given that water has a
density of 1g/mL. Determine the concentration of salt in:
(a) mg/L , (b) ppm.
Answer:
a) Concentration of salt in mg/L = 2g/100mL
b) concentration in ppm = 20000 ppm
Explanation:
Percentage composition of salt by weight in water = 2%
Density of water = 1 g/mL
100 mL of water will has a mass of 100 g
Mass of salt in 100 g of water = 2% ×100 g = 2 g
Therefore, 2 g of salt is dissolved in 100 mL of solution
Concentration of salt in 100 mL of solution = 2g/100mL
a) Concentration in mg/L
Mass of salt = 2 g = 2000 mg
Volume of solution = 100 mL = 0.1 L
Concentration in mg/L = 2000 mg/0.1 L
Concentration in mg/L = 20000 mg/L
b) Concentration in ppm
1 ppm = 1mg/L
Therefore, concentration in ppm = 20000 ppm
Sodium chloride is a ____ substance because the atoms within are arranged in repeating patterns.
work bank
- crystalline
- hydrogen bonds
- hydrophilic
- hydrophobic
- polar molecule
- solvent
The orbits of the planets in our solar system are
not
a Elliptical, circular
b Circular, elliptical
C Circular, oval
d None of the above
Answer:
A
Explanation:
I don't know how to say how I got it.
Answer:
d
Explanation:
the orbits of the planets in our circular elliptical and circular
PLEASE HELP!! Answer whatever ones you can please and thank you!!!!
1. A gas with a volume of 4.0 L at a pressure of 2.03 atm is allowed to expand to a volume of 12.0 L. What is the pressure in atm in the container if the temperature remains constant. Please show work (including the equation you used).
2.The volume of a gas is 200 mL at 350.0 kPa pressure. What will the volume be when the pressure is reduced to 120.0 kPa, assuming the temperature remains constant. Please show all work for full credit. Please show work (including the equation you used).
3.What is the original pressure of a bike tire if the current pressure is 150 atm and the volume changed from 1000 mL to 700 mL. Please show work (including the equation you used).
These problems can be solved using the gas laws. The combined gas law states that PV/T = k, where P is the pressure, V is the volume, T is the temperature (in Kelvin), and k is a constant. From this relationship, you can figure out the change in pressure, volume, or temperature of a gas provided that one of those three parameters remains unchanged. This will be shown in the problems given.
1. Here, the pressure and volume of a gas change while the temperature remains constant. Since PV/T = k, if T is also constant, then the relationship becomes PV = k. In other words, the pressure and volume of a gas at a constant temperature are inversely proportional to each other. This can be expressed mathematically as [tex]P_1V_1=P_2V_2[/tex] (also called Boyle's Law), where P₁ and V₁ denote the initial pressure and volume, and P₂ and V₂ denote the final (or changed) pressure and volume, respectively.
We are given a gas with an initial pressure, P₁, of 2.03 atm and an initial volume, V₁, of 4.0 L. We are also told that the gas expands to a final volume, V₂, of 12.0 L. So, we are looking for P₂: The pressure of the gas when the volume has expanded from 4.0 to 12.0 L. From Boyle's Law,
[tex]P_2=\frac{P_1V_1}{V_2}[/tex].
Thus,
[tex]\[P_2=\frac{\left ( 2.03 \text{ atm} \right )\left ( 4.0 \text{ L} \right )}{\left ( 12.0 \text{ L} \right )}\] = 0.67 atm.[/tex]
Since the pressure and volume of a gas are inversely proportional, as one increases, the other decreases, and vice versa.
2. This is another Boyle's Law problem, but this time, we have to figure out what the final volume will be when the pressure of a gas is changed. Since the pressure is reduced, we can deduce that the volume must increase (notice the parallel with the previous question). We again turn to Boyle's Law, and this time we solve for V₂:
[tex]V_2=\frac{P_1V_1}{P_2}[/tex]
from which we obtain
[tex]\[V_2=\frac{\left ( 350.0 \text{ kPa} \right )\left ( 200 \text{ mL} \right )}{\left ( 120.0 \text{ kPa} \right )}\] = 583 mL.[/tex]
It's not clear whether 200 mL (V₁) should be assigned three significant figures or one. I gave the answer to three significant figures; the answer to one significant figure would be 600 mL.
3. We use Boyle's Law once more here, but our word problem has us working backwards (it's also not explicitly mentioned that temperature remains constant, but it should be reasonable to assume so). The current pressure of the gas inside the bike tire is 150 atm at a volume of 700 mL . But we want to know what the initial pressure of the gas was at a volume of 1000 mL. In other words, we want to solve for the P₁ in Boyle's Law:
[tex]P_1=\frac{P_2V_2}{V_1}.[/tex]
Since the volume of the gas had decreased from 1000 mL (V₁) to 700 mL (V₂), and the pressure and volume of a gas at a constant temperature are inversely proportional, we would expect the pressure of the gas to have increased; that is, our P₁ should be less than 150 atm.
[tex]\[P_1=\frac{\left ( 150 \text{ atm} \right )\left ( 700 \text{ mL} \right )}{\left ( 1000 \text{ mL} \right )}\] = 105 atm.[/tex]
will mark BRAINLYIST
please help
1.00mol is the correct answer
Acidified water is electrolysed by using carbon electrodes. What is produced
at Negative carbon electrode
Answer:
Hydrogen gas
Explanation:
During electrolysis of acidified water, H+ ions are reduced to H2 gas at the negative carbon electrode (cathode) and hence hydrogen gas is liberated at cathode.
How many moles are there in 4.7 x 10^24 molecules of water?
Answer:
7.81 moles
Explanation:
(4.7×10^24 )×1 moles divided by 6.02×10^23 molecules
What is a catalyst and why is it used in chemical reactions?
Answer:
A catalyst is a substance that can be added to a reaction to speed up the process without being absorbed by it. Catalysts usually work by lowering the activation energy or modifying the mechanism of a reaction. Proteins that act as catalysts in biochemical reactions are known as enzymes.
Explanation:
Propane, C3H8, a fuel used in many outdoor grills, burns in oxygen to produce carbon dioxide gas, CO2, and water vapor, H2O, as shown in the reaction below. If 2.0 mol of propane are burned (reacted with oxygen), how many moles of carbon dioxide will be produced?
Answer:
6 moles of CO₂
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O
From the balanced equation above,
1 mole of C₃H₈ reacted to produce 3 moles CO₂.
Finally, we shall determine the number of mole of CO₂ produced by the reaction of 2 moles of C₃H₈. This can be obtained as follow:
From the balanced equation above,
1 mole of C₃H₈ reacted to produce 3 moles CO₂.
Therefore, 2 moles of C₃H₈ will react to produce = 2 × 3 = 6 moles of CO₂.
Thus, 6 moles of CO₂ were obtained from the reaction.
Но Water Lewis steucture
what are asking commet it and I might be able to help
It’s cold outside and you decide to cook some pasta. As you boil the noodles, the kitchen window begins to fog up. Which processes are at work here?
boiling and freezing
vaporization and condensation
evaporation and thawing
condensation and evaporation
Answer:
condensation and evaporation
Explanation:
condensation forms when warm humid air contacts cold surface. during cold months.
What element should I do a project on?
Answer:
Project scope statement?
Explanation:
it's good one just do research on it
why is it necessary to specify temperature when giving Ka value
Answer:
Because the equilibrium constant is only at constant at temperature. Changing the temperature changes the Ka.
Matching
Enter the letter of the box whose contents best match the description.
8
8
8
a
b
с
e
f
v a mixture of molecules
atoms of a pure elementa metal
molecules of an element
va solid compound
a mixture of elements
a. box a
b. box e
c. box b
d. box f
e. box d
f. box c
QUESTION 10
Answer:
a mixture of molecules - Box f
atoms of a pure elementa metal - Box D
a solid compound - Box C
a mixture of elements - Box A
Explanation:
Box a has mixture of elements which forms a solid like shape but there are different elements present in the box. The box f has mixture of molecules in which many atoms are combined together. Box c has solid compound with single element.
3NaHCO, +CHO - CH. Na 0, +300, +3H, 0.
Name one reactant and one product
What would be the volume, in liters, of 85.5 grams of carbon monoxide at STP?
Which of the following is a characteristic of a scientific theory
1. It explains how nature works.
2. It is based on a single experiment.
3. It should not be possible to replicate its results.
4. It should not be possible to replicate its observations.
NEED URGENT!!!!!
Answer:
number one
Explanation:
hope I helped
In an isolated system, mass can neither be
created or destroyed.
ube
FALSE
TRUE
Answer:
True
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
Hope it helps
someone help ,, I'll give brainliest lolll .
Answer:
the correct answer is c, how easily something catches flames
2.00 L of a gas is collected at 25.0°C and 745.0 mmHg. What is the volume at 760.0 mmHg
and 273K?*
1.7960L
Explanation:
the mass of the gas is constant in both instances
pv/T=constant(according to pv=nRT)
745mmHg*2L/298K=760mmHg*v/273K
v=1.7960L
A gas tank contains 2.5 moles of oxygen, 7.0 moles of nitrogen and 0.5 mole of water vapor. The total pressure of the mixture is 852 torr. Calculate the partial pressure of each gas. Show work.
Answer:
The partial pressure of each gas is:
Oxygen= 213 torrNitrogen= 596.4 torrWater Vapor= 42.6 torrExplanation:
The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:
PT = PA + PB
This relationship is due to the assumption that there are no attractive forces between the gases.
Dalton's partial pressure law can also be expressed in terms of the mole fraction of the gas in the mixture. The mole fraction is a dimensionless quantity that expresses the ratio of the number of moles of a component to the number of moles of all the components present.
The mole fraction of a gas in a gas mixture is given by:
XA = nA / nT
This fraction will always be less than 1.
So in a mixture of two or more gases, the partial pressure of gas A can be expressed as:
PA = XA * PT
In this case, you know:
number of moles of oxygen= 2.5 molesnumber of moles of nitrogen= 7.0 molesnumber of moles of water vapor= 0.5 molesSo, the number of total moles nT is calculated as:
nT= number of moles of oxygen + number of moles of nitrogen +number of moles of water vapor
Then:
nT= 2.5 moles + 7.0 moles + 0.5 moles
nT= 10
So, the mole fraction of the gas in the mixture is:
mole fraction of oxygen = [tex]\frac{2.5 moles}{10 moles}[/tex] = 0.25mole fraction of nitrogen = [tex]\frac{7 moles}{10 moles}[/tex] = 0.7mole fraction of water vapor = [tex]\frac{0.5 moles}{10 moles}[/tex] = 0.05Being the total presurre (PT) equal to 852 torr, then:
Poxygen= 0.25*852 torr= 213 torrPnitrogen= 0.7*852 torr= 596.4 torrPwater vapor= 0.05*852 torr= 42.6 torrThe partial pressure of each gas is:
Oxygen= 213 torrNitrogen= 596.4 torrWater Vapor= 42.6 torr