Mole Concept

What is the molar mass of NaCl?

• 58.45g/mol

• 28g/mol

• 12g/mol

• 6.02 x 10²³

Calculate the % composition by mass of oxygen present in H₂SO₄.

• 16.3%

• 65.25%

• 32.6%

• 57.14%

Tags

NGSS.HS-PS1-7

How many moles are 98.3 grams of aluminum hydroxide, Al(OH)₃?

• 1.26 moles
• 0.8 moles
• 7,673.4 moles
• 150 moles

Tags

NGSS.HS-PS1-7

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

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Convert 25 g of NaBr to molecules

• 102.96 molecules

• 0.24 molecules

• 1.45x10²³ molecules

• 2.34 x 10²⁰molecules

Tags

NGSS.HS-PS1-7

What is the empirical formula for thr compound, C_xH_yO_z , if the ratio C: H: O equal to 2: 2.5 : 1

• C₂H₂O₁

• C₂H₅O₁

• C₄H₅O₂

• C₃H₂O₂

The empirical formula for hydrocarbon A is C₂H₇O. If the molar mass of the hydrocarbon is 141 g/mol, determine the molecular formula for this hydrocarbon.

• C₂H₇O

• C₄H₁₄O₂

• C₆H₂₁O₃

• C₈H₂₈O₄

Calculate the percentage of composition by mass of oxygen in Al(HCO₃)₃.

• 22.86 %

• 68.57 %

• 78.26 %

• 40.50 %

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

• NaPO₂

• Na₂PO₃

• Na₃PO₄

• NaPO₄

Which of the following statement are true about the formula of dinitrogen monoxide, N₂O?

• The relative molecular mass is 28.

• One molecule of N₂O consists of one nitrogen atom and one oxygen atom.

• One mole of N₂O contains 6.02 x 10²³ atoms of nitrogen.

• One mole of N₂O consists of two mole of nitrogen atom and one mole of oxygen atom.

Tags

NGSS.MS-PS1-1