Stoichiometry Practice

Which formula is an empirical formula?

• N₂O₄

• NH₃

• C₃H₆

• P₄O₁₀

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram-formula mass = 120. grams per mole)?

• 20%

• 27%

• 46%

• 53%

Which represents the greatest mass of chlorine?

• 1 mole of chlorine

• 1 atom of chlorine

• 1 gram of chlorine

• 1 molecule of chlorine

Which sample contains a total of 9.0 x 10²³ atoms?

• 0.50 mole of HCl

• 0.75 mole of H₂O

• 1.5 moles of Cu

• 1.5 moles of H₂

Tags

NGSS.HS-PS1-7

A compound contains 46.7% nitrogen and 53.3% oxygen by mass. What is the empirical formula of the compound?

• NO

• N₂O

• N₂O₃

• N₂O₅

Given the balanced equation: 2C + 3H₂ → C₂H₆ What is the total number of moles of C that must completely react to produce 2.0 moles of C₂H₆?

• 1.0 mol

• 2.0 mol

• 3.0 mol

• 4.0 mol

Tags

NGSS.HS-PS1-7

Which compound has the greatest percent composition by mass of sulfur?

• BaS

• CaS

• MgS

• SrS

Which sample contains a total of 6.0 x 10²³ atoms?

• 23 g Na

• 24 g C

• 42 g Kr

• 78 g K

Given the reaction: N₂(g) + 3 H₂(g) ↔ 2 NH₃(g) What is the mole-to-mole ratio between nitrogen gas and hydrogen gas?

• 1:2

• 1:3

• 2:2

• 2:3

What is the formula mass of Al₂(SO₄)₃?

• 123

• 150

• 214

• 342