2009 年
化學 · 共 50 題 · 點擊選項即時核對答案
The electronic arrangements of three chemical species are shown below. W : 2, 1 X²⁺ : 2, 8 Y⁻ : 2, 8, 7 Which of the elements W, X and Y are in the same period of the Periodic Table ?
In which of the following reactions does nitrogen exhibit three different oxidation numbers in the species involved ?
Which of the following properties is NOT possessed by both carbon and nitrogen ?
The table below shows whether displacement reaction occurs between metals W, X, Y and Z with their ions. ‘✓’ represents that displacement reaction occurs, while ‘x’ represents that displacement reaction does not occur.
| W | X | Y | Z | |
|---|---|---|---|---|
| W²⁺(aq) | — | x | ✓ | ✓ |
| X⁺(aq) | ✓ | — | ✓ | ✓ |
| Y²⁺(aq) | x | x | — | ✓ |
| Z⁺(aq) | x | x | x | — |
Which of the following is the strongest reducing agent ?
What is the percentage by mass of oxygen in Na₂CO₃·10H₂O ? (Relative atomic masses : H = 1.0, C = 12.0, O = 16.0, Na = 23.0)
Which of the following rust prevention methods does NOT match with the iron-made object ?
| Rust prevention method | Iron-made object | |
|---|---|---|
| painting | gate | |
| greasing | machinery parts | |
| zinc plating | food can | |
| chromium plating | car bumper |
A colourless aqueous solution of compound Z can conduct electricity and turns blue litmus paper red. It can be deduced that
Questions 8 and 9 refer to the following diagram. A zinc plate and a copper plate dipped in 1 M sulphuric acid, connected through an ammeter.
Which of the following observations can be made in the above set-up ?
Questions 8 and 9 refer to the following diagram. A zinc plate and a copper plate dipped in 1 M sulphuric acid, connected through an ammeter.
What will occur when the circuit is closed ?
X is an acid. 25.0 cm³ of 0.20 M solution X requires 30.0 cm³ of 0.50 M sodium hydroxide solution for complete neutralisation. What is the basicity of X ?