AP CHEM Unit 1 Day 1 Review

The average atomic mass of a newly discovered element is 10.600 amu. It has two naturally occurring isotopes. One has a mass of 10.000 and a natural abundance of 70.000%. What is the isotopic mass of the other isotope?

• 10.000

• 9.0000

• 12.000

• 11.000

A new element has two isotopes, one with a mass of 40.0 amu that is 75% abundant. The average atomic weight of the element is 40.50 amu. What is the isotopic mass of the other isotope?

• 40.0 amu

• 42.0 amu

• 41.0 amu

• 44.0 amu

108 g of an element Z reacts with oxygen to form 204 g of the oxide Z₂O₃. What is the element Z?

• Al

• Sc

• Ag

• Mn

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Which diagram(s) best characterize(s) a mixture? 

• III and IV only
• I, II and III only
• IV only 
• I and III only

Which contains the largest number of atoms?

• 3.0 mL of CH₃OH (density = 1.2g/mL)

• 3.0 moles of CO

• 3.0 mg of water

• 3.0x10²² molecules of nitrogen gas

Estimate the number of moles of hydrogen in 176g of pentanol, C₅H₁₁OH. The molar mass of pentanol is 88g/mol.

• 12 mol H

• 144 mol H

• 24 mol H

• 72 mol H

Tags

NGSS.HS-PS1-7

An Olympic medal contains 71.5% of gold by mass. How much gold could be extracted from a medal that weighs 115 grams?

• 0.417 mol

• 1.33 mol

• 0.817 mol

• 14.1 mol