##### Print Instructions

NOTE: Only your test content will print.
To preview this answer key, click on the File menu and select Print Preview.

See our guide on How To Change Browser Print Settings to customize headers and footers before printing.

# Stoichiometry

Print Answer Key (Only the test content will print)

## Stoichiometry Answer Key

1.
If $W_2$ is the weight of solute in grams or Kgs and $W_1$ is the weight of solvent in grams or kgs, then what is the concentration of such a solution in parts per million (ppm)?
1. Parts per million (ppm) = $(W_2)/(W_1 + W_2) xx 10^6$
2. Parts per million (ppm) = $[(W_1 + W_2)/W_1] xx 10^-3$
3. Parts per million (ppm) = $(W_1)/(W_1+W_2) + 10^2$
4. parts per million (ppm) = $(W_2)/ (W_1 -W_2) xx 10^5$

2.
A sample of KCl weighing 10 g is dissolved in 200 mL of water. What is the weight percent of KCl in the solution (density of water = 1 g/mL)?
1. 4.76%
2. 4.53%
3. 4.95%
4. 4.85%
3.
Calculate the mass of sodium in kilograms present in 95 kilograms of a crude sample of sodium nitrate, whose percentage purity is 70%.
1. 17.99 Kg
2. 16.56 Kg
3. 18.35 Kg
4. 11.25 Kg

4.
What do you term the ratio of the mass of the solution to the mass of an equal volume of water at a specified temperature?
1. Specific gravity
2. Density
3. Molarity
4. Molality
5.
If W grams of solute, having an equivalent weight E, is dissolved in V liters of the solution, what is the expression of normality (N) in this case?
1. $N = (W/E) (1/V)$
2. $N = (WE)/V$
3. $N = (WV)/E$
4. $N = (EV)/W$

6.
The concentration expressed in terms of mole fraction and molality is independent of temperature.
1. True
2. False
7.
How many grams of NaOH are present in 1 mole of NaOH?
1. 40 grams
2. 50 grams
3. 60 grams
4. 70 grams

8.
The mole is based on
1. speed of light.
2. Planck's constant.
3. pi.
4. Avogadro's number.
9.
The sum of the mole fractions of all the components in a given solution is equal to unity.

10.
Determine the number of moles present in 0.0632 g of sulfur.
• Award credit for any one of the following answers:
• 0.002 mol
• 0.00197 mol
• 0.0020 mol
You need to be a HelpTeaching.com member to access free printables.
Already a member? Log in for access.    |    Go Back To Previous Page