VHCC CHM 111 Chapter 3 Quiz

One mole of sulfur (S) is equal to home many atoms?

• 32 x10²³ atoms

• 1.6x10²³ atoms

• 1.20 x 10²³ atoms

• 6.02 x 10²³ atoms

5.11 x 10²³ atoms of lithium (Li) is equal to how many moles?

• 1.18 moles

• 0.351 moles

• 1.34 moles

• 0.849 moles

Tags

NGSS.HS-PS1-7

How many atoms would be contained in 454 grams of iron (Fe)?

• 6.02 x 10²³ atoms

• 8.14x10²³ atoms

• 4.90 x 10²⁴ atoms

• 55.85 x 10²³ atoms

What is the percent by mass of fluorine in CaF₂ ?

• 24%

• 49%

• 51%

• 65%

What is the percent composition by mass of oxygen in the compound magnesium sulfate?

• 20%

• 27%

• 46%

• 53%

Which pair has the same empirical formula?

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

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

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

Tags

NGSS.MS-PS1-1

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.1 % C, 8.7% H, and 52.2% O. What is the molecular formula for glycerol?

• C₄H₁₂O₂

• CH₂O

• C₂H₄O₄

• C₃H₈O₃

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation? P₄O₁₀ + H₂O --> H₃PO₄

• 6:4

• 4:6

• 1:1

• 3:1