Complete Test Bank Moles, Concentration, Dilutions Chapter 5

Chapter 5: Moles, concentrations, and dilutions: making sense of chemical numbers

Test Bank

Type: multiple response question

Title: Chapter 05 - Question 01

1) You can have a mole of which of the following? Select any that apply.

a. Atoms

b. Ions

c. Molecules

d. Electrons

e. Protons

Type: multiple choice question

Title: Chapter 05 - Question 02

2) Which of the following numbers represents the Avogadro constant?

a. 6 × 10²³

b. 1 × 10²³

c. 6 × 10²

d. 23

e. 6²³

Type: multiple choice question

Title: Chapter 05 - Question 03

3) Which of the following is the correct mass of one mole of ¹²C?

a. 1 g

b. 12.5 g

c. 6 × 10²³ g

d. 72 g

e. 12 g

Type: multiple choice question

Title: Chapter 05 - Question 04

4) The molar mass of a compound has which of the following units?

a. mol

b. g mol^-1

c. G

d. amu

e. mol g^-1

Type: multiple choice question

Title: Chapter 05 - Question 05

5) Which of the following has the greatest mass, noting that the molar mass of carbon is 12; the molar mass of oxygen is 16; the molar mass of hydrogen is 1; and the molar mass of nitrogen is 15?

a. 10 mol H₂

b. 2 mol CH₄

c. 5 mol H₂O

d. 3 mol NH₃

e. 5 mol O₂

Type: multiple choice question

Title: Chapter 05 - Question 06

6) How many moles are there in 30 g of C?

a. 360 mol

b. 30 mol

c. 2.5 mol

d. 0.4 mol

e. 12 mol

Type: multiple choice question

Title: Chapter 05 - Question 07

7) What is the mass of 1.5 mol CH₃OH?

a. 48 g

b. 21.333 g

c. 32 g

d. 0.05 g

e. 1.5 g

Type: multiple choice question

Title: Chapter 05 - Question 08

8) 2 moles of the amino acid glycine have a mass of 152 g. What is the molar mass of glycine?

a. 152 g mol^-1

b. 0.013 g mol^-1

c. 2 g mol^-1

d. 304 g mol^-1

e. 76 g mol^-1

Type: multiple choice question

Title: Chapter 05 - Question 09

9) How many moles are there in 121.6 g of glycine?

a. 1.6 mol

b. 0.625 mol

c. 121.6 mol

d. 8.76 × 10³ mol

e. 76 mol

Type: multiple response question

Title: Chapter 05 - Question 10

10) Which of the following two quantities are identical?

a. 1 dm³

b. 1 m³

c. 1 L

d. 100 mL

e. 1 cm³

Type: multiple choice question

Title: Chapter 05 - Question 11

11) The concentration of a substance is defined as the number of moles in what volume?

a. 1 mL

b. 1 cm³

c. 1 L

d. 1 m³

e. 1 μL

Type: multiple choice question

Title: Chapter 05 - Question 12

12) What amount of hydrogen chloride is present in 500 mL of a solution with a concentration of 0.5 mol L^-1?

a. 0.5 mol

b. 250 mol

c. 1000 mol

d. 0.001 mol

e. 0.25 mol

Type: multiple choice question

Title: Chapter 05 - Question 13

13) How many moles are present in 10 mL of a sodium chloride (salt) solution, with a concentration of 2 mol L^-1?

a. 0.02 mol

b. 20 mol

c. 0.2 mol

d. 5 mol

e. 0.1 mol

Type: multiple choice question

Title: Chapter 05 - Question 14

14) What is the concentration of 100 mL of a solution containing 2.5 moles of glucose?

a. 40 mol L^-1

b. 0.025 mol L^-1

c. 25 mol L^-1

d. 250 mol L^-1

e. 0.25 mol L^-1

Type: multiple choice question

Title: Chapter 05 - Question 15

15) How many moles of NaOH do we need to prepare 250 mL of a 2M solution?

a. 0.5 mol

b. 500 mol

c. 0.008 mol

d. 8 mol

e. 2 mol

Type: multiple choice question

Title: Chapter 05 - Question 16

16) How many moles of NH₃ do we need to prepare 100 mL of a 0.5M solution?

a. 0.5 mol

b. 0.2 mol

c. 200 mol

d. 0.05 mol

e. 50 mol

Type: multiple choice question

Title: Chapter 05 - Question 17

17) We have 100 mL of a solution of NaCl with a concentration of 0.5 mol L^-1 and want to dilute it to a concentration of 0.1 mol L^-1. How much water would we need to add to achieve this?

a. 0.5 L

b. 0.4 L

c. 500 L

d. 0.005 L

e. 0.1 L

Type: multiple choice question

Title: Chapter 05 - Question 18

18) A sample of a solution with concentration of 0.005 mol L^-1 has a molar absorptivity of 150 L mol^-1 cm^-1 at 350 nm. What absorbance will be measured by a UV-visible spectrophotometer when the sample is measured in a cuvette with a path length of 1 cm at 350 nm?

a. 3.3 × 10^-3

b. 0.75

c. 30 000

d. 75

e. 0.075

Type: multiple choice question

Title: Chapter 05 - Question 19

19) A substance, X, has a molar absorptivity of 1250 L mol^-1 cm^-1 at 325 nm. A sample of X gives an absorbance of 0.8 when measured in a UV-visible spectrophotometer at 325 nm with a path length of 1 cm. What is the concentration of the sample of X?

a. 1000 mol L^-1

b. 1 mol L^-1

c. 1563 mol L^-1

d. 6.4 × 10^-4 mol L^-1

e. 1.56 mol L^-1

Type: multiple choice question

Title: Chapter 05 - Question 20

20) Two compounds, A and B, react with the stoichiometry 1:3, i.e. A + 3B. If there are 0.1 moles of A present in a sample initially, how many moles of B must be added for A to be completely consumed?

a. 0.1 mol

b. 0.3 mol

c. 0.0333 mol

d. 3 mol

e. 1 mol

Type: multiple choice question

Title: Chapter 05 - Question 21

21) A solution containing red blood cells at a concentration of 2000 cells per mL undergoes three serial dilution steps, whereby 1 mL of starting solution is diluted with 9 mL of solvent at each step. What is the concentration of red blood cells after the final dilution step?

a. 666 cells mL^-1

b. 2.47 cells mL^-1

c. 2 cells mL^-1

d. 20 cells mL^-1

e. 74.1 cells mL^-1

Type: multiple choice question

Title: Chapter 05 - Question 22

22) 25 mL of a growth medium containing bacteria at a concentration of 3 × 10⁵ cells per litre is diluted to a volume of 0.05 L. What is the concentration of bacteria after dilution?

a. 1.5 × 10⁶ cells L^-1

b. 1.75 × 10⁸ cells L^-1

c. 6.7 × 10^-6 cells L^-1

d. 6 × 10⁵ cells L^-1

e. 1.5 × 10⁵ cells L^-1