Class Test

Theoretical yield = 73g

Actual yield = 62g

Calculate the percent yield.

• 1.16%

• 116%

• 85%

• 76%

P₄ + 3O₂ --> P₄O₆

What is the limiting reactant is 12 moles of P₄ react with 15 moles of O₂?

• P₄

• O₂

• P₄O₆

• None of the above

Complete the equation for the percent yield of a chemical reaction:

Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield

• theoretical yield; actual yield

• mass of the substance and molar mass

• mass of pure substance and mass of impure subsatance

P₄ + 6Cl₂ --> 4PCl3 The reaction of 75.0g P₄ with excess chlorine gas produces 110g PCl₃ in lab. Find the theoretical yield and calculate percent yield for the reaction.

• 78%

• 64%

• 27%

• 33%

Find the percent composition of N₂S₂.

• N: 69.6% S: 30.4%

• N:36% S: 75.6%

• N: 96.6% S: 3.4%

• N: 30.4% S: 69.6%

Whats the empirical formula of a molecule containing 40.0 % C, 6.7% H, and 53.3% oxygen?

• CHO

• CH₂O

• CH₃0

• C₂HO₂

What is the molecular formula of a compound with an empirical formula of C₂OH₄and a molecular mass of 88 grams per mole?

• C₂O₄H₈

• C₈O₂H₄

• C₄O₂H₈

• C₄O₈H₂

An empirical formula:

• is a formula that calculates the coefficients of a compound in a balanced equation.

• is the simplest whole-number ratio of moles of elements in the compound.

• is the largest whole-number ratio of moles of elements in the compound.

What is the percent composition of hydrogen in ammonium sulfide?

• 11.8%

• 8%

• 6.1%

• 3.5%

All of the following are empirical formulas except

• H₂O

• N₂O₅

• C₁₀H₂₃

• P₄H₁₀