Matter Module 7: The Mole Concept

Which is the correct formula unit for sodium chloride?

• A. NaCl

• B. Na2Cl

• C. Na3Cl2

• D. Na2Cl5

Caffeine is a natural compound commonly found in coffee, tea, chocolate, and softdrinks. What is the molar mass of caffeine (C8H10N4O2)?

• A. 171.1 g/mol

• B. 189.4 g/mol

• C. 194.2 g/mol

• D. 199.8 g/mol

The pain reliever mefenamic acid contains an active ingredient called Ibuprofen C13H18O2. What is the molecular mass for this compound?

• A. 200.1 g/mol

• B. 206.3 g/mol

• C. 222.3 g/mol

• D. 240.54 g/mol

Amedeo Avogadro is an Italian scientist who used a constant number to represent the mole of a substance. Which of these represents the number of units in one mole of any substance?

• A. 3.01 x 1023

• B. 3.01 x 1024

• C. 6.02 x 1023

• D. 6.02 x 1024

Which represents a mole?

• A. 6 g of NaCl

• B. 3.01 x 1023 CH4 molecules

• C. 6.02 x 1023 F atoms

• D. 25 g graphite, C-atom

Tags

NGSS.HS-PS1-7

How is molar mass of a substance calculated? .

• A. Atomic mass of an element minus the number of atoms as indicated by chemical formula

• B. Number of atoms as indicated by chemical formula divided by atomic weight.

• C. Atomic mass of an element multiplied by the number of each atom of each element as indicated by chemical formula then add all the products of all the elements.

• D. . Number of atoms as indicated by chemical formula divided by atomic mass of an element.

If one mole of Aluminum weighs 26.98 grams, what is the mass in grams of 4.30 moles of Aluminum?

• A. 22.68 g Al

• B. 6.27 g Al

• C. 27.28 g Al

• D. 116 g Al

Which is the correct way of converting moles to mass?

• A. number of moles multiplied by molar mass

• B. number of moles divided by the molar mass

• C. number of moles divided by the Avogadro’s number

• D. number of moles multiplied by Avogadro’s number

How many moles are contained in 34g of NH3?

• A. 1 mol

• B. 2 mol

• C. 17 mol

• D. 34 mol

What is the mass of 4.39 mol Na?

• A. 191 g

• B. 252 g

• C. 120 g

• D. 101 g