Chem Unit 4 Quiz 5

What is Avogadro's Number? 

• 6.02 x 10²³
• - 6.02 10²³
• 6.02 x 10²²
• 6,020,000,000,000

Tags

NGSS.HS-PS1-7

How many atoms are in 1 mole of NaCl? 

• 6.02 x 10²³
• 58 
• 11
• 17

Tags

NGSS.HS-PS1-7

Which has more molecules?

• 1 mole H₂O
• 1 mole Al(OH)₃
• 1 mole NaCl
• There are all the same

What is the mass of one mole of aluminum?

• 26.982 g
• 13 g
• 53.985 g
• 14 g

Molar mass is in units of ________.

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

Tags

NGSS.HS-PS1-7

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

Which pair has the same empirical formula?

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

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013
• %Cu= 79.854   %S= 20.145
• %Cu= 35.946   %S= 64.054

What is the percentage of oxygen in carbon dioxide? (CO2)

• 27.3%
• 72.7%
• 30%
• 70%