Mathematics of Molecules Assessment

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

• Molecular Formula

• Chemical Formula

• Empirical Formula 

• Distance Formula

How many molecules are in 2.5 mol of NaCl?

• 1.5 x 10²⁴ molecules

• 1.5 molecules

• 4.15 molecules

• 1.5 x 10²³ molecules

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇

• C₂H₄O₂ and C₆H₁₂O₆

• C₃H₆O₃ and C₂H₆O₂

• CH₄ and C₂H₆

diphosphorus pentoxide

• P₂O₅

• PO₅

• P₅O₂

• P₂O₆

T/F
If 2 compounds have the same empirical formula, they are the same (same properties, structure, etc.)

• True

• False

What is the empirical formula for the following molecular formula: C₅H₁₂

• C₅H₁₂

• CH₃

• CH₂

• C_2.5H₆

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

• C₂H₂

• C₂H₂

• C₁H₁

• CH₂

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

• Na₂Cl

• NaCl₂

• NaCl

• Na₂Cl₂

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

• H₂O

• H₂O₂

• HO

• HO₂

What is the percent by mass of magnesium in MgO?

• 20%

• 40%

• 50%

• 60%