A unit that contains $$6.02 \times 10$$^{23}$$ particles of a substance.

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

$$1 \text{ mol} = 6.02 \times 10$$^{23}$$ molecules

$$1.8 \times 10$$^{24}$$ molecules

Question 1

Which of the following best describes a mole in chemistry?

Accepted Answer

A unit that contains $$6.02 	imes 10$$^{23}$$ particles of a substance.

Question 2

How many molecules are present in 2.5 moles of carbon dioxide ($$CO_2$$)?

Accepted Answer

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

Question 3

A sample contains $$1.204 	imes 10$$^{24}$$ atoms of silver (Ag$). How many moles of silver are present?

Accepted Answer

2.00 moles

Question 4

What is the chemical formula for a compound formed between an unknown metal X and fluorine, given the formula $$XF_3$$?

Accepted Answer

The metal X is most likely in Group 3A.

Question 5

Calculate the molar mass of ammonium chloride ($$NH_4Cl).$$

Accepted Answer

53.50 g/mol

Question 6

How many hydrogen atoms are present in one formula unit of $$(NH_4$)_2SO_4$$?

Accepted Answer

8

Question 7

Which of the following is the correct molar mass for calcium chloride ($$CaCl_2$$)?

Accepted Answer

110.98 g/mol

Question 8

If you have 7.0 moles of sulfur ($$S$$), how many atoms of sulfur do you have?

Accepted Answer

$$4.2 	imes 10$$^{24}$$ atoms

Question 9

Which of the following best describes the relationship between atomic mass unit (amu) and molar mass?

Accepted Answer

The value of the molar mass in grams per mole is numerically equal to the formula mass in amu.

Question 10

How many moles are in $$2.11 	imes 10$$^{24}$$ atoms of H_2$?

Accepted Answer

3.50 mol

Question 11

Which of the following is the correct formula for dihydrogen sulfide?

Accepted Answer

$$H_2S$$

Question 12

A box of donuts contains 12 donuts. This is an example of which type of counting unit in chemistry?

Accepted Answer

A dozen

Question 13

Which of the following is the correct formula mass for $$MgSO_4$$?

Accepted Answer

120.37 amu

Question 14

What is the molar mass of water ($$H_2O$$)?

Accepted Answer

18.02 g/mol

Question 15

Which of the following best describes Avogadro’s number?

Accepted Answer

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

Question 16

Which of the following is a correct conversion factor for converting moles to molecules?

Accepted Answer

$$1 	ext{ mol} = 6.02 	imes 10$$^{23}$$ molecules

Question 17

Which of the following compounds contains the greatest number of atoms per formula unit?

Accepted Answer

$$(NH_4$)_2SO_4$$

Question 18

If you have 3.0 moles of sodium fluoride ($$NaF$$), how many molecules do you have?

Accepted Answer

$$1.8 	imes 10$$^{24}$$ molecules

Question 19

Which of the following best describes the process of balancing a chemical equation?

Accepted Answer

Ensuring the same number of each type of atom appears on both sides of the equation.

Chemical Quantities, The Mole, and Molar Mass – Study Notes

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