Chapter 3: Changes in Matter

Question 1

How much does 10 g Fe increase mass of Fe₂O₃?

Answer 1

Calculate mass increase based on reaction stoichiometry.

Question 2

How many moles CO₂ react with 5.0 moles O₂ in the reaction C₂H₄ + O₂ → CO₂ + H₂O?

Answer 2

Do the calculation.

Question 3

How many moles O₂ needed to form 20.0 g H₂O in the reaction C₂H₄ + O₂ → CO₂ + H₂O?

Answer 3

Do the calculation.

Question 4

What mass CO₂ produced if 100.0 mL water formed in the reaction C₂H₄ + O₂ → CO₂ + H₂O?

Answer 4

Do the calculation.

Question 5

What mass water forms with 540 g aspirin in the reaction 2 C₇H₆O₃ + C₄H₆O₃ → 2 C₉H₈O₄ + H₂O?

Answer 5

Use mole ratios and molar masses.

Question 6

What mass carbon needed for 6.00 moles Fe₂O₃ in the reaction Fe₂O₃ + 3 C → 2 Fe + 3 CO?

Answer 6

Do the calculation.

Question 7

Define radioactivity.

Answer 7

The spontaneous emission of particles or energy from unstable nuclei.

Question 8

Fill table for alpha, beta, gamma radiation: symbol, charge, penetration.

Answer 8

Alpha (α), +2 charge, low penetration; Beta (β), -1 charge, medium penetration; Gamma (γ), no charge, high penetration.

Question 9

How many days until 18 g sample of Iodine-131 < 1.0 g if half-life is 8 days?

Answer 9

Do the calculation.

Question 10

Differences between nuclear fission and fusion?

Answer 10

Fission splits heavy nuclei, releases energy; fusion combines light nuclei, releases more energy.