2010 年
化學 · 共 50 題 · 點擊選項即時核對答案
How many electrons and neutrons are there in a doubly charged cation formed from ⁵⁵₂₅Mn ?
| Number of electrons | Number of neutrons | |
|---|---|---|
| 23 | 30 | |
| 23 | 32 | |
| 25 | 28 | |
| 25 | 30 |
Consider the industrial processes as shown below: crude oil —(Process I)→ heavy oil + other fractions —(Process II)→ naphtha + other hydrocarbons Which of the following combinations is correct ?
| Process I | Process II | |
|---|---|---|
| is a chemical change. | is a physical change. | |
| is a chemical change. | is a chemical change. | |
| is a physical change. | is a physical change. | |
| is a physical change. | is a chemical change. |
X²⁺ ion has an electronic arrangement of 2, 8, 8. Which of the following statements concerning the carbonate of X is INCORRECT ?
Assuming that the total volume of 20 drops of water is 1.0 cm³, what is the number of molecules in 1 drop of water ? (Avogadro’s constant = 6.02 × 10²³ mol⁻¹; density of water = 1.0 g cm⁻³; relative atomic masses : H = 1.0, O = 16.0)
Which of the following set-ups can be used to dry hydrogen chloride gas ?
Which of the following components of air is NOT obtained industrially from fractional distillation of liquid air ?
In an experiment, a mixture of ethanol and acidified potassium dichromate solution is heated under reflux to obtain ethanoic acid. Which of the following apparatus should be used in the experiment ?
Naturally occurring magnesium has three isotopes : ²⁴Mg, ²⁵Mg and ²⁶Mg. The relative abundance of the ²⁵Mg isotope is 10%. What is the relative abundance of the ²⁶Mg isotope ? (Relative atomic mass : Mg = 24.3)
In which of the following set-ups would the voltmeter display the greatest magnitude of voltage reading ?
The polymer formed from the polymerisation of 1,1-dichloroethene is commonly used in making food wrap for microwave cooking. Which of the following can represent a part of the structure of the polymer ?
