Mole Calculations Practice

How many grams are in 7.8 moles of NaCl?

• 476 grams

• 456 grams

• 452 grams

• 462 grams

N₂ + 3H₂ → 2NH₃

How many moles of hydrogen are needed to react with 2 moles of nitrogen?

• 1

• 2

• 3

• 6

Calculate the number of particles (atoms) in 0.250 moles of silver.

• 1.62 x 10²⁵ atoms Ag

• 4.15 x 10^-25 atoms Ag

• 1.51 x10²³ atoms Ag

• 27.0 atoms Ag

Tags

NGSS.HS-PS1-7

What is the percent composition of C in C₄H₁₀?

• 48.0%

• 58.0%

• 17.2%

• 82.8%

4NH₃(g) + 6NO(g) --> 5N₂(g) + 6H₂O(g)

How many moles of ammonia are needed to form 0.65 moles of nitrogen with excess quantities of nitrogen monoxide?

• 0.65 moles of NH₃

• 4.0 moles of NH₃

• 2.6 moles of NH₃

• 0.52 moles of NH₃

Tags

NGSS.HS-PS1-7

2Na(s) + Cl₂(g) --> 2NaCl(s)

3.0 moles of chlorine are reacted with 3.0 sodium, what was the theoretical yield (how much NaCl should have been produced)?

• 6.0 mol NaCl

• 3.0 mol NaCl

• 9.0 mol NaCl

• 1.5 mol NaCl

Tags

NGSS.HS-PS1-7

If the theoretical yield is 18 moles and the actual yield is 14 moles, what is the percent yield?

• 128.6%

• 32.0%

• 77.8%

• 92.4%

What percentage of the total atomic mass of carbon monoxide (CO) is composed of oxygen?

• 29%

• 43%

• 57%

• 73%

What percentage of the total atomic mass of lithium phosphide (Li₃P) is composed of phosphorus?

• 13%

• 29%

• 40%

• 60%

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%
• 27%
• 46%
• 53%