Q: Which of the following best describes a mole in chemistry?

A unit that represents 6.02 \times $$10^{23}$$ particles (atoms, molecules, or ions)

Q: How many molecules are present in 3.0 moles of H$$_2O$$?

$$1.81 \times 10$$^{24}$$ molecules

Q: How many atoms are in 2.5 moles of aluminum (Al)?

$$1.51 \times 10$$^{24}$$ atoms

Q: A patient receives 0.500 moles of vitamin C (C$$_6H$_8O$_6) in an IV. $$How many molecules of vitamin C did they receive?

$$3.01 \times 10$$^{23}$$ molecules

Q: Which conversion factor would you use to convert from grams of Ag to moles of Ag?

$$\frac{1\ \text{mol Ag}}{107.9\ \text{g Ag}}$$

Q: If you have 0.100 moles of C$$_2H$_6O$$, how many hydrogen atoms do you have?

$$4.82 \times 10$$^{23}$$ atoms

Q: A sample contains 18.0 g of water (H$$_2O). $$How many molecules of water are present? (Molar mass of H$$_2O = 18.02 g/$$mol)

$$6.02 \times 10$$^{23}$$ molecules

Question 1

Which of the following best describes a mole in chemistry?

Accepted Answer

A unit that represents 6.02 	imes $$10^{23}$$ particles (atoms, molecules, or ions)

Question 2

How many molecules are present in 3.0 moles of H$$_2O$$?

Accepted Answer

$$1.81 	imes 10$$^{24}$$ molecules

Question 3

A sample contains $$1.2 	imes 10$$^{24}$$ atoms of sulfur (S). How many moles of sulfur are present?

Accepted Answer

$$0.50$$ moles

Question 4

What is the molar mass of C$$_2H$_6O ($$ethanol)?

Accepted Answer

$$46.08 g/$$mol

Question 5

How many moles of hydrogen atoms are in 0.250 moles of C$$_6H$_{14}O$$?

Accepted Answer

$$1.75$$ moles

Question 6

A chemist needs 36.0 g of carbon (C) for an experiment. How many moles of carbon does this represent? (Atomic mass of C = 12.01 g/mol)

Accepted Answer

$$3.00$$ moles

Question 7

How many atoms are in 2.5 moles of aluminum (Al)?

Accepted Answer

$$1.51 	imes 10$$^{24}$$ atoms

Question 8

Calculate the mass in grams of 0.75 moles of NaCl. (Na = 22.99 g/mol, Cl = 35.45 g/mol)

Accepted Answer

$$43.98 g$$

Question 9

A bottle contains 59.8 g of water (H$$_2O). $$How many moles of water are present? (Molar mass of H$$_2O = 18.02 g/$$mol)

Accepted Answer

$$3.32$$ moles

Question 10

Which of the following statements about Avogadro’s number is TRUE?

Accepted Answer

It is the number of particles in one mole of any substance.

Question 11

How many moles of oxygen atoms are in 2.0 moles of C$$_9H$_8O$_4 ($$aspirin)?

Accepted Answer

$$8.0$$ moles

Question 12

A patient receives 0.500 moles of vitamin C (C$$_6H$_8O$_6) in an IV. $$How many molecules of vitamin C did they receive?

Accepted Answer

$$3.01 	imes 10$$^{23}$$ molecules

Question 13

Which conversion factor would you use to convert from grams of Ag to moles of Ag?

Accepted Answer

$$\frac{1\ 	ext{mol Ag}}{107.9\ 	ext{g Ag}}$$

Question 14

If you have 0.100 moles of C$$_2H$_6O$$, how many hydrogen atoms do you have?

Accepted Answer

$$4.82 	imes 10$$^{23}$$ atoms

Question 15

Which of the following is the correct sequence for converting grams of a compound to number of molecules?

Accepted Answer

Grams $$ \rightarrow $$ Moles $$ \rightarrow $$ Molecules

Question 16

A laboratory procedure requires 0.200 moles of NaCl. What mass of NaCl should be weighed out? (Na = 22.99 g/mol, Cl = 35.45 g/mol)

Accepted Answer

$$11.7 g$$

Question 17

Which of the following best explains why the mole is a useful unit in chemistry?

Accepted Answer

It allows chemists to count and relate measurable masses to numbers of atoms, molecules, or ions.

Question 18

How many moles of oxygen atoms are in 0.500 moles of H$$_2SO$_4$$?

Accepted Answer

$$2.00$$ moles

Question 19

A sample contains 18.0 g of water (H$$_2O). $$How many molecules of water are present? (Molar mass of H$$_2O = 18.02 g/$$mol)

Accepted Answer

$$6.02 	imes 10$$^{23}$$ molecules

The Mole and Calculating Molar Mass: Study Notes for GOB Chemistry

Study Guide - Practice Questions

Study Guide - Flashcards