Empirical formula and percent composition review

The molar mass of an element is equal to its...

• Atomic mass
• Atomic number
• Oxidation number
• Valence electrons

Tags

NGSS.HS-PS1-7

What is the molar mass of sodium?

• 11
• 23
• 45.98
• 3

What is the mass of one mole of aluminum?

• 27 g
• 13 g
• 54 g
• 14 g

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol
• 35.453 g/mol
• 22.990 g/mol
• 58.443 g/mol

What is the mass of one mole of aluminum chloride (remember to determine the correct formula first)?

• 62.435g
• 116.399g
• 133.341g
• 97.888g

What percentage of the total atomic mass of carbon monoxide (CO) is composed of carbon?

• 29%

• 43%

• 57%

• 73%

What percentage of the total atomic mass of magnesium bromide (MgBr₂) is composed of magnesium?

• 13%

• 43%

• 63%

• 87%

Tags

NGSS.MS-PS1-1

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013
• %Cu= 79.854   %S= 20.145
• %Cu= 35.946   %S= 64.054

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

• 27.48% Mg

• 43.11% Mg

• 16.00% Mg

• 12.63% Mg

What is the empirical formula for C₃H₈

• CH
• C₃H₈
• C₆H₁₆
• CH_2.7