Copy of Percent Comp, Empirical Formula, and Molecular Formula (5/28/2026)

What is the percent composition of NH₃?

a.) N %

b.) H %

What is the percent composition of Na₂S₂O₃?

a.) Na %

b.) S %

c.) O %

What is the percent composition of Ca₃(PO₄)₂?

a) Ca %

b.) P %

c.) O %

What is the empirical formula for a compound comprising 43.6% phosphorus (P) and 56.4% oxygen (O)?

a.) Molar composition (step 1 - pay attention to Sigfigs):

P mol

O mol

b.) Molar ratios (step 2 - round to nearest whole number):

P

O

c.) Empirical formula:

What is its molecular formula if the compound from question 4 has a molecular mass of 283.88 g/mol?

a.) Empirical Mass

b.) Formula Units

c.) Molecular Formula

What is the empirical formula for a compound comprising 40.0% carbon (C), 6.7% hydrogen (H), and 53.3% oxygen (O)?

a.) Molar composition (step 1 - pay attention to Sigfigs):

C mol

H mol

O mol

b.) Molar ratios (step 2 - round to nearest whole number):

C

H

O

c.) Empirical Formula:

What is its molecular formula if the compound from question 6 has a molecular mass of 360.36 g/mol?

a.) Empirical mass?

b.) Formula Units?

c.) Molecular Mass?

A compound is comprised of 1.61% H, 22.23% N, and 76.16% O. If it has a molecular mass of 63.01 g/mol, what is the molecular formula?

a.) Empirical formula

b.) Empirical Mass

c.) Formula Units

d.) Molecular Formula

A compound has an empirical formula of C₃O and a molecular mass of 104.06 g/mol. What is the molecular formula?

Molecular formula