1999 年
化學 · 共 50 題 · 點擊選項即時核對答案
The table below shows the ability of four substances W, X, Y and Z to conduct electricity. (In the table, ✓ and ✗ respectively represent ‘can conduct electricity’ and ‘cannot conduct electricity’.)
| Substance | Solid State | Liquid State | Aqueous Solution |
|---|---|---|---|
| W | ✗ | ✓ | ✓ |
| X | ✗ | ✗ | ✓ |
| Y | ✗ | ✗ | ✗ |
| Z | ✓ | ✓ | (insoluble in water) |
Which of the substances is likely to be zinc chloride ?
Consider the electrolysis experiment shown below :
Which of the following statements concerning this experiment is correct ?
Which of the following ions is responsible for the yellow colour of topaz ?
Which of the following adverse effects associated with excessive intake of food additives is correct ?
| Food additive | Adverse effect | |
|---|---|---|
| tartrazine (a yellow colouring) | causing hyperactivity | |
| sodium nitrite | causing stomach ulcer | |
| monosodium glutamate | causing cancer | |
| sodium chloride | causing allergy |
Potassium permanganate solution acidified with dilute sulphuric acid is a commonly-used oxidizing agent. Dilute nitric acid is not used to acidify potassium permanganate solution because
At room temperature and pressure, 8.0 g of oxygen and 20.0 g of gas X occupy the same volume. What is the molar mass of X ? (Relative atomic mass : O = 16.0; molar volume of gas at room temperature and pressure = 24.0 dm³)
The compound X₂S contains 58.9% of X by mass. What is the relative atomic mass of X ? (Relative atomic mass : S = 32.1)
Which of the following processes would NOT produce hydrogen gas ?
Ionic compound X has the formula AB₂, where A and B represent the cation and anion respectively. If both A and B have the same electronic arrangement, X may be
Which of the following solutions would produce a white precipitate with sodium hydroxide solution ?