Mole Concept

How many atoms of copper in 65.0 g of copper(II) chloride?

•  $2.91\ \times10^{23}\ atoms$  

•  $3.95\ \times10^{23}\ atoms$  

•   $5.81\times10^{23}\ atoms$  

•   $7.90\times10^{23}\ atoms$  

How many atoms of chlorine in 65.0 g of copper(II) chloride?

• $2.91\ \times10^{23}\ atoms$

• $3.95\ \times10^{23}\ atoms$

• $5.81\times10^{23}\ atoms$

• $7.90\times10^{23}\ atoms$

If the molecular formula for compound Z is C₈H₁₈. What is the empirical formula?

• C₈H₁₈

• C₄H₈

• CH₉

• C₄H₉

If one Monster energy drink contains 0.16 g of caffeine, how many moles of caffeine do we consume when we drink 1 can? The chemical formula for caffeine is C₈H₁₀N₄O₂.

• 194 mol

• $1.57\ \times10^{-3}\ mol$

• 
  

  $8.2474\times10^{-4}\ mol$

• $3.14\ \times10^{-3\ }mol$

Caffeine has formula unit C₈H₁₀N₄O₂. Calculate the molar mass of caffeine.

• 102

• 24

• 194

• 124

Acetone, C₃H₆O, is the main component of nail polish remover. Calculate the molar mass of acetone.

• 42 g/mol

• 10 g/mol

• 32 g/mol

• 58 g/mol

Chalk is mostly made of calcium carbonate, CaCO₃. If it took 48.6 g of chalk to write your name on the sidewalk, how many moles of calcium carbonate does your name contain?

• 0.49 mol

• 0.97 mol

• 1.03 mol

• 2.06 mol

How many atoms are contained in 25 g of NaBr?

• 6.54 x 10²³ atoms

• 3.27 x 10²³ atoms

• 2.93 x 10²³ atoms

• 1.46 x 10²³ atoms

How many molecules are in 2.00 moles of H₂O?

• 1.81x10²⁴ molecules

• 3.61x10²⁴ molecules

• 1.20x10²⁴ molecules

• 6.02x10²³ molecules

How many atoms are in 1.50 moles of Hg?

• 9.03x10²³ atoms

• 6.02x10²³ atoms

• 4.82x10²⁵ atoms

• 1.21x10²⁶ atoms