Q: Which of the following is the correct setup to convert $75.0\ \mathrm{g}$ of Ag to moles? (Molar mass of Ag = $107.87\ \mathrm{g/mol}$)

$75.0\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{107.87\ \mathrm{g}}$

Question 1

Which of the following best describes the purpose of molar mass in chemical calculations?

Accepted Answer

It is used to convert between the mass of a substance and the number of moles.

Question 2

Given that the molar mass of magnesium (Mg) is $24.31\ \mathrm{g/mol}$, how many grams are in $2.50$ moles of Mg?

Accepted Answer

$60.8\ \mathrm{g}$

Question 3

A jeweler needs $0.750$ mole of silver (Ag) for a design. If the molar mass of Ag is $107.87\ \mathrm{g/mol}$, how many grams of silver are required?

Accepted Answer

$80.9\ \mathrm{g}$

Question 4

A box of salt contains $737\ \mathrm{g}$ of NaCl. If the molar mass of NaCl is $58.44\ \mathrm{g/mol}$, how many moles of NaCl are present?

Accepted Answer

$12.6\ \mathrm{mol}$

Question 5

Which of the following conversion factors would you use to convert grams of Mg to moles of Mg?

Accepted Answer

$\frac{1\ \mathrm{mol\ Mg}}{24.31\ \mathrm{g\ Mg}}$

Question 6

If you have $50.0\ \mathrm{g}$ of NaCl, how many moles do you have? (Molar mass of NaCl = $58.44\ \mathrm{g/mol}$)

Accepted Answer

$0.856\ \mathrm{mol}$

Question 7

A chemist needs $15.0\ \mathrm{g}$ of magnesium for a reaction. How many moles of magnesium does this represent? (Molar mass of Mg = $24.31\ \mathrm{g/mol}$)

Accepted Answer

$0.617\ \mathrm{mol}$

Question 8

Which of the following statements is TRUE about molar mass?

Accepted Answer

Molar mass is the mass of one mole of a substance, expressed in grams per mole.

Question 9

A patient is prescribed a medication that requires $0.200\ \mathrm{mol}$ of NaCl. How many grams of NaCl should be administered? (Molar mass of NaCl = $58.44\ \mathrm{g/mol}$)

Accepted Answer

$11.7\ \mathrm{g}$

Question 10

If you have $5.00\ \mathrm{mol}$ of Mg, what is the total mass in grams? (Molar mass of Mg = $24.31\ \mathrm{g/mol}$)

Accepted Answer

$121.6\ \mathrm{g}$

Question 11

A laboratory experiment requires $0.500\ \mathrm{mol}$ of NaCl. What mass of NaCl should be weighed out? (Molar mass of NaCl = $58.44\ \mathrm{g/mol}$)

Accepted Answer

$29.2\ \mathrm{g}$

Question 12

Which calculation correctly converts $100.0\ \mathrm{g}$ of Mg to moles? (Molar mass of Mg = $24.31\ \mathrm{g/mol}$)

Accepted Answer

$\frac{100.0\ \mathrm{g}}{24.31\ \mathrm{g/mol}}$

Question 13

A nutrition label states that a serving contains $0.250\ \mathrm{mol}$ of NaCl. What is the mass of NaCl in this serving? (Molar mass of NaCl = $58.44\ \mathrm{g/mol}$)

Accepted Answer

$14.6\ \mathrm{g}$

Question 14

Which of the following is the correct setup to convert $75.0\ \mathrm{g}$ of Ag to moles? (Molar mass of Ag = $107.87\ \mathrm{g/mol}$)

Accepted Answer

$75.0\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{107.87\ \mathrm{g}}$

Question 15

A chemical reaction requires $3.00\ \mathrm{mol}$ of NaCl. What is the mass in grams needed? (Molar mass of NaCl = $58.44\ \mathrm{g/mol}$)

Accepted Answer

$175.3\ \mathrm{g}$

Question 16

If a sample contains $0.250\ \mathrm{mol}$ of Mg, what is its mass in grams? (Molar mass of Mg = $24.31\ \mathrm{g/mol}$)

Accepted Answer

$6.08\ \mathrm{g}$

Calculations Involving Molar Mass: Converting Between Mass and Moles

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