Q: A sample of gas occupies 2.0 L at 1.0 atm. If the pressure is increased to 4.0 atm at constant temperature, what will be the new volume according to Boyle's Law?

$$V_2$$ = \frac{$$P_1$$ $$V_1$$}{$$P_2$$} = \frac{1.0 \times 2.0}{4.0} = 0.5\ \text{L}$$

Q: A solution contains 5.0 g of NaCl dissolved in 100 g of water. What is the percent mass/mass of NaCl in the solution?

$$\frac{5.0}{100.0} \times 100 = 5.0\%$$

Q: Which of the following is the correct formula for calculating molarity?

$$\text{Molarity} = \frac{\text{moles of solute}}{\text{liters of solution}}$$

Q: A solution contains 0.25 mol of KOH in 500 mL of solution. What is the molarity of the solution?

$$\frac{0.25}{0.5} = 0.50\ \text{M}$$

Q: A solution is prepared by dissolving 10 g of solute in enough water to make 250 mL of solution. What is the percent mass/volume of the solution?

$$\frac{10}{250} \times 100 = 4.0\%$$

Q: Which of the following is the correct conversion between pressure units?

$$1\ \text{atm} = 760\ \text{mmHg} = 14.7\ \text{psi}$$

Q: A patient receives an intravenous solution containing 0.9% NaCl (mass/volume). How many grams of NaCl are present in 500 mL of this solution?

$$0.9\% = \frac{\text{grams}}{500\ \text{mL}} \times 100 \Rightarrow \text{grams} = \frac{0.9 \times 500}{100} = 4.5\ \text{g}$$

Q: Which of the following is the correct formula for calculating parts per million (ppm)?

$$\text{ppm} = \frac{\text{mass of solute}}{\text{mass of solution}} \times 10^6$

Q: A solution contains 0.002 g of lead in 1.0 L of water. What is the concentration in ppm?

$$\text{ppm} = \frac{0.002}{1000} \times 10^6$ = 2\ \text{ppm}$$

Question 1

Which of the following is a strong acid commonly encountered in laboratory settings?

Accepted Answer

HClO\_4

Question 2

A sample of gas occupies 2.0 L at 1.0 atm. If the pressure is increased to 4.0 atm at constant temperature, what will be the new volume according to Boyle's Law?

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$}{$$P_2$$} = \frac{1.0 	imes 2.0}{4.0} = 0.5\ 	ext{L}$$

Question 3

Which of the following is NOT a strong base?

Accepted Answer

NH\_3

Question 4

A solution contains 5.0 g of NaCl dissolved in 100 g of water. What is the percent mass/mass of NaCl in the solution?

Accepted Answer

$$\frac{5.0}{100.0} 	imes 100 = 5.0\%$$

Question 5

Which of the following polyatomic ions has a -2 charge?

Accepted Answer

SO\_4$$^{2-}$$

Question 6

A gas sample at 300 K and 2.0 atm occupies 3.0 L. What will be its volume at 600 K and 1.0 atm? (Use the Combined Gas Law)

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$ $$T_2$$}{$$P_2$$ $$T_1$$} = \frac{2.0 	imes 3.0 	imes 600}{1.0 	imes 300} = 12.0\ 	ext{L}$$

Question 7

Which of the following is the correct formula for calculating molarity?

Accepted Answer

$$	ext{Molarity} = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 8

A solution contains 0.25 mol of KOH in 500 mL of solution. What is the molarity of the solution?

Accepted Answer

$$\frac{0.25}{0.5} = 0.50\ 	ext{M}$$

Question 9

Which of the following ions is commonly found in household bleach?

Accepted Answer

ClO$$^{-}$$

Question 10

A solution is prepared by dissolving 10 g of solute in enough water to make 250 mL of solution. What is the percent mass/volume of the solution?

Accepted Answer

$$\frac{10}{250} 	imes 100 = 4.0\%$$

Question 11

Which of the following is the correct conversion between pressure units?

Accepted Answer

$$1\ 	ext{atm} = 760\ 	ext{mmHg} = 14.7\ 	ext{psi}$$

Question 12

A patient receives an intravenous solution containing 0.9% NaCl (mass/volume). How many grams of NaCl are present in 500 mL of this solution?

Accepted Answer

$$0.9\% = \frac{	ext{grams}}{500\ 	ext{mL}} 	imes 100 \Rightarrow 	ext{grams} = \frac{0.9 	imes 500}{100} = 4.5\ 	ext{g}$$

Question 13

Which of the following ions is responsible for the hardness of water?

Accepted Answer

Ca$$^{2+}$$

Question 14

A gas at 25°C is heated to 75°C. What is the temperature in Kelvin after heating?

Accepted Answer

$$75 + 273 = 348\ 	ext{K}$$

Question 15

Which of the following is the correct formula for calculating parts per million (ppm)?

Accepted Answer

$$	ext{ppm} = \frac{	ext{mass of solute}}{	ext{mass of solution}} 	imes 10^6$

Question 16

A solution contains 0.002 g of lead in 1.0 L of water. What is the concentration in ppm?

Accepted Answer

$$	ext{ppm} = \frac{0.002}{1000} 	imes 10^6$ = 2\ 	ext{ppm}$$

Question 17

Which of the following polyatomic ions is found in fertilizers and is essential for plant growth?

Accepted Answer

PO\_4$$^{3-}$$

Question 18

A 1.0 L solution contains 0.1 mol of HCl. What is the molarity of the solution, and is HCl a strong acid?

Accepted Answer

Molarity = $$\frac{0.1}{1.0} = 0.1\ 	ext{M}$$; HCl is a strong acid.

GOB Chemistry Study Notes: Acids, Bases, Gas Laws, and Solution Chemistry

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