Molar mass and % composition

What is the molar mass of CO₂?

• 12 g/mol

• 16 g/mol

• 32 g/mol

• 44 g/mol

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

• 27.7% Mg

• 23.6% Mg

• 16.00% Mg

• 24.3% Mg

What is the mass percentage of Carbon in Carbon dioxide (CO₂)?

• 27.3%

• 42.9%

• 72.7%

• 58.1%

What are the units in molar mass?

• grams
• moles
• moles/gram
• grams/mole

Which list of number of atoms in Mg(NO₃)₂ is right?

• Mg - 1 NO - 6

• Mg-1 N- 6 O-6

• Mg -1 N-1 O-5

• Mg-1 N-2 O-6

Tags

NGSS.MS-PS1-1

What is the percent by mass of sodium in NaCl?

• 39.3%

• 61.7%

• 35.2%

• 64.8%

Which list of number of atoms in K₃PO₄ is right?

• K-3 PO-4

• K -3 P-1 O-4

• K -3 P-4 O-4

• K -3 P-5 O-4

Tags

NGSS.MS-PS1-1

The chemical formula of magnesium phosphide is

• MgP
• Mg₂P₃
• Mg₃P₂
• Mg₃(PO₄)₂

The mass % of H in methane (CH₄) is:

• 74.9%

• 92%

• 25.1%

• 4%

Tags

NGSS.HS-PS1-7

Calculate the molar mass of KOH.

• 28.2 g/mol

• 56.1 g/mol

• 84.5 g/mol

• 112.1 g/mol