1.简单
In a chemical equation, what does the symbol (aq) after a formula mean?
- AA pure liquid
- BA gas
- CDissolved in water
- DA solid
2.简单
According to the Arrhenius definition, what does a base produce in water?
- AChloride ions (Cl⁻)
- BHydrogen ions (H⁺)
- CHydroxide ions (OH⁻)
- DCarbonate ions (CO₃²⁻)
3.简单
What is activation energy?
- AThe energy stored in the products
- BThe minimum energy reacting particles need for a reaction to happen
- CThe total energy released once the reaction has finished
- DThe energy needed to melt a solid
4.中等
What is the formula of the hydroxide ion?
- AOH⁻
- BH₃O⁺
- COH⁺
- DO²⁻
5.中等
Vinegar contains acetic acid, CH₃COOH. Which functional group makes it an acid?
- AThe carboxyl group, –COOH
- BThe amino group, –NH₂
- CThe hydroxyl group of an alcohol, –OH
- DThe methyl group, –CH₃
6.中等
How does atomic radius change going down a group?
- AIt decreases, then increases
- BIt stays the same
- CIt decreases
- DIt increases
7.困难
Which list puts fluorine, chlorine and bromine in order of increasing electronegativity?
- AF < Cl < Br
- BBr < Cl < F
- CCl < Br < F
- DBr < F < Cl
8.困难
关于可逆反应中的催化剂,下列哪项说法正确?
- A它只加快正反应并阻止逆反应
- B它使两个方向的反应同样加快
- C它增加平衡时产物的量
- D它在反应进行时被消耗
答案
- 1. C · Dissolved in water
- 2. C · Hydroxide ions (OH⁻)
- 3. B · The minimum energy reacting particles need for a reaction to happen
- 4. A · OH⁻
- 5. A · The carboxyl group, –COOH
- 6. D · It increases
- 7. B · Br < Cl < F
- 8. B · 它使两个方向的反应同样加快
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