AP Chemistry Unit 1 Review

The average atomic mass rhenium, Re, is 186.21 amu. If 37.1% of rhenium has mass# = 185, what is the other stable isotope?

• Rhenium-183
• Rhenium-181
• Rhenium-187
• Rhenium-189

Tags

NGSS.HS-PS1-8

What is the empirical formula if you have 36.84% nitrogen and 63.16% oxygen?

• NO
• N₂O₃
• N₂O₄
• N₂O₅

A 5.00 g sample of a compound consisting of calcium and chlorine contains 1.82 g of calcium and 3.23 g of chlorine. What is the empirical formula?

• CaCl₂

• Ca₂Cl₄

• Ca₂Cl₂

• Ca₄Cl₂

How many molecules are in 2.5 mol of NaCl?

• 1.5 x 10²⁴ molecules

• 1.5 molecules

• 4.15 molecules

• 1.5 x 10²³ molecules

Which pair has the same empirical formula?

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

What is the molecular formula if the empirical formula is C₂H₅ and the molecular molar mass is 58.14 g/mol?

• C₂H₅
• C₄H₁₀
• C₁H_2.5
• C₄H₈

What would be the mass of 1.5mol H₂O

• 20
• 27
• 32
• 40

How many moles are in 16.94g of water?

• 16.94 mol H₂O
• 0.9401 mol H₂O
• 305.3 mol H₂O
• 1.063 mol H₂O

Tags

NGSS.HS-PS1-7

Which of the following properties uniquely identifies every element?

• Number of valence electrons
• Phase at room temperature
• Number of protons
• Charge of the atom

Which element would have similar properties to Sulfur?

• Nitrogen
• Oxygen
• Flourine
• Chlorine

Tags

NGSS.HS-PS1-1