Chemical Composition Unit

Which pair has the same empirical formula?

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

Which formula is an empirical formula?

• H₂O₂

• C₂H₆O₁₂

• CaCl₂

• N₂O₈

N₃O₃ can be classified as which type of formula?

• Empirical

• Molecular

• Both

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

What are the units for molar mass?

• grams
• amu
• grams/mole
• liters

Tags

NGSS.HS-PS1-7

Fluorine is diatomic.  What is the molar mass of fluorine gas?

• 18.998 g/mol
• 37.996 g/mol
• 9 g/mol
• 18 g/mol

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

• 28 grams

• 24 grams

• 6.02 grams

• 1.2 grams

*How many atoms are in a 3.56 g sample of Cu?

• 3.37 x 10²² Cu atoms

• 6.02 x 10²³ Cu atoms

• 0.056 Cu atoms

• 1 Cu atom

*What is the molar mass of B₂(CO₃)₃?

• 81.6 g/mol

• 94.8 g/mol

• 38.8 g/mol

• 201.6 g/mol

*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