Chemical Quantities

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

• 20%
• 27%
• 46%
• 53%

In which compound is the percent composition by mass of Cl equal to 42%?

• HClO (gram formula mass = 52 g/mol)
• HClO₂ (gram formula mass = 68 g/mol)
• HClO₃ (gram formula mass = 84 g/mol)
• HClO₄ (gram formula mass = 100 g/mol)

What is the percent by mass of N in (NH₄)₂S?

• 47.1%

• 68.1%

• 44.1%

• 41.1%

Which pair has the same empirical formula?

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

Find the percentage composition of Mg in Mg₃(PO₄)₂.

• 27.48% Mg

• 43.11% Mg

• 16.00% Mg

• 12.63% Mg

Which list of number of atoms in MgF₂ is right?

• Mg : 1--  F :  1
  
• Mg : 1 -- F :  2
  
• Mg :  2 --  F :   1
  
• Mg : 0 --   F :  1
  

Tags

NGSS.MS-PS1-1

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

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

What molecular formula would match with the empirical formula is CH₂O

• CH₂O₄

• C₂H₄O

• C₄H₈O₈

• C₆H₁₂O₆

What is the equation for calculating percent composition?

• mass of element/mass of compound = x 100
• mass of compound/mass of element = x 100 
• total mass/molar mass = x 100 
• molar mass/molar mass = x 100 

What is the molarity of 1 mole of Ba⁺ in 2 L of water

• 1 M

• 2 M

• .5 M

• .25 M