1.Easy
Which of these is a heterogeneous mixture?
- ASugar dissolved in tea
- BAir
- COil and water
- DSalt dissolved in water
2.Easy
What is an alloy?
- AA pure metal in its natural state
- BA compound formed when a metal reacts with oxygen
- CA nonmetal that conducts electricity
- DA mixture of a metal with one or more other elements
3.Easy
A neutral atom has 11 protons. How many electrons does it have?
- A12
- B11
- C22
- D10
4.Medium
On an energy diagram, the products are at a lower energy than the reactants. What kind of reaction is shown?
- ANuclear
- BExothermic
- CEndothermic
- DReversible only
5.Medium
A solution has a pH of 10. What is its pOH at 25 °C?
- A14
- B24
- C10
- D4
6.Medium
A reaction has ΔH = −890 kJ/mol. What does the negative sign tell you?
- AThe reaction needs a catalyst
- BThe reaction is exothermic
- CThe reaction is at equilibrium
- DThe reaction is endothermic
7.Hard
A reaction at equilibrium has a very large equilibrium constant (K much greater than 1). What does this tell you?
- AAt equilibrium, the mixture contains mostly reactants
- BAt equilibrium, the mixture contains mostly products
- CThe reaction is very fast
- DThe reaction cannot reach equilibrium
8.Hard
Which of these is a redox reaction?
- AAgNO₃ + NaCl → AgCl + NaNO₃
- BCaCO₃ → CaO + CO₂
- CNaOH + HCl → NaCl + H₂O
- DZn + CuSO₄ → ZnSO₄ + Cu
Answer key
- 1. C · Oil and water
- 2. D · A mixture of a metal with one or more other elements
- 3. B · 11
- 4. B · Exothermic
- 5. D · 4
- 6. B · The reaction is exothermic
- 7. B · At equilibrium, the mixture contains mostly products
- 8. D · Zn + CuSO₄ → ZnSO₄ + Cu
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