Empirical Formulas Lesson

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

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

Which of the following is considered an empirical formula?

• CH₃COOH
• C₆H₁₂O₆
• H₂O
• H₂O₂

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇
• C₂H₄O₂ and C₆H₁₂O₆
• C₃H₆O₃ and C₂H₆O₂
• CH₄ and C₂H₆

How many sodium ions are there in 2.5 mol of NaCl?

• 1.5 x 10²⁴ ions

• 1.5 molecules

• 6.022 x 10²³ ions

• 3.0 x 10²⁴ molecules

Answer explanation

2.5 mol of NaCl contains 2.5 mol of sodium ions and 2.5 mol of chloride ions.

If making 5 mol out of 2.5 mol here doesn't make sense to you, please inform your teacher.

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen (N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Answer explanation

1.00 grams of a compound containing copper and chlorine was found to contain 0.524 grams of copper. Determine the empirical formula.

• CuCl

• CuCl₂

• CuCl_1.97

• Cu₂Cl

Answer explanation

Tags

NGSS.HS-PS1-7