Practice Molar Mass, Mole Conversion and Percent Composition

How many molecules are in 2.5 mol of NaCl?

• 1.50 x10²⁴ molecules

• 1.50 molecules

• 4.15 molecules

• 1.51 x10²⁴ molecules

How many moles are in 19.82 g Mg?

• 1.23 mol Mg

• 481.70 mol Mg

• 1.00 mol Mg

• 0.82 mol Mg

How many moles are in 3.01 x 10²² atoms of magnesium?

• 0.05 moles

• 1.81 x 10⁴⁶ moles

• 5.00 x 10²¹ moles

• 5.00 moles

Tags

NGSS.HS-PS1-7

How many grams are in 1.2 x 10²⁴ atoms of C?

• 29.34 grams

• 23.94 grams

• 6.02 grams

• 1.21 grams

Tags

NGSS.HS-PS1-7

What is the percent composition by mass of sulfur (S) in the compound MgSO₄?

• 20.22%

• 19.85%

• 26.64%

• 28.64%

Calculate the number of atoms in 0.0340 g Zn.

• 5.200 x 10^-4 atoms Zn
• 3.130 x 10²³ atoms Zn
• 3.130 x 10²⁰ atoms Zn
• 1 atom Zn

Tags

NGSS.HS-PS1-7

Determine the mass of 4.20 moles of C₆H₁₂

• 354 g

• 84 g

• 337 g

• 421 g

Which pair has the same empirical formula?

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

What is the molar mass of PbSO₄

• 303.3 g/mol
• 294.7g/mol
• 163.8g/mol
• 372g/mol

How many grams are in 1.2 moles of Neon?

• 0.05 grams

• 16.6 grams

• 21.2 grams

• 24 grams