Empirical and Molecular Formula

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

Tags

NGSS.HS-PS1-7

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

• 20%
• 27%
• 46%
• 53%

Tags

NGSS.HS-PS1-7

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

• ionic formula
• covalent formula
• empirical formula
• molecular formula

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.

What is the empirical formula of a substance with the molecular formula C₂H₄?

• C₂H₂

• C₂H₂

• C₁H₁

• CH₂

Tags

NGSS.MS-PS1-1

What is the empirical formula of a substance with the molecular formula X₂₀Y₁₅?

• X₁₀Y₁₅

• X₅Y₃

• X₄Y₃

• X₂₀Y₁₅

Tags

NGSS.MS-PS1-1

What is the empirical formula of a substance with the molecular formula Se₈F₁₂?

• Se₈F₁₂

• Se₂F₃

• Se₄F₃

• SeF

What is the empirical formula for hydrogen peroxide (H₂O₂)?

• H₂O

• H₂O₂

• HO

• HO₂