Final exam review SPRING

What does a mole in chemistry measure?

• particles of a substance

• volume of a substance

• color of a substance

• density of a substance

Tags

NGSS.HS-PS1-7

Which of the following statements regarding the mole is INCORRECT?

• A mole is a unit of quantity equal to 6.02 x 10²³ particles.

• The number of particles in a mole is known as Avogadro’s number.

• A mole of particles of an element is numerically equal to the atomic mass of the element.

• none of the above

Tags

NGSS.HS-PS1-7

What is the molar mass of fluorine gas?
(beware!)

• 18.998 g/mol
• 38 g/mol
• 9 g/mol
• 18 g/mol

How many molecules are in 27.5 grams of NaOH

• 41.4 molecules

• 4.14 x 10²³ molecules

• 4.14 x 10²⁵ molecules

• 1.83 x 10^-21 molecules

Tags

NGSS.HS-PS1-7

How many moles are in 2.85 x 10¹⁸ atoms of iron, Fe?

• 41.4 molecules

• 4.14 x 10²³ molecules

• 4.14 x 10²⁵ molecules

• 1.83 x 10^-21 molecules

What is the mass in grams of 5.90 mol C₈H_18?

• .0512 g
• 19.4 g
• 673 g
• 389 g

How many moles are in 19.82 g Mg? 

• 1.226mol Mg
• 481.7mol Mg
• 1.000mol Mg
•  0.8156 mol Mg

How many moles of hydrogen, H₂, are needed to react with 2.0 moles of nitrogen, N₂?

• 3 moles H₂

• 0.66 moles H₂

• 6 moles of H₂

• 1.5 moles H₂

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