1 - 10 of 44 Questions
# | Question | Ans |
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1. |
The presence of an impurity in substance will cause the melting point to A. be zero B. reduce C. increase D. be stable Detailed SolutionImpurities disrupt the repeating pattern of forces that holds the solid together. So a smaller amount of energy is required to melt the part of the solid surrounding the impurity. If less energy is required, then this explains the melting point depression (lowering) observed from impure solids. The more impure the solid is, the more the structure is disrupted and the greater the variation in intermolecular forces in different areas of the solid.There is an explanation video available below. |
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2. |
What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen? A. 5 dm 3 B. 20 dm 3 C. 15 dm 3 D. 10 dm 3 |
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3. |
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is A. carbon-14 B. phosphorus-32 C. cobalt-60 D. iodine-131 |
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4. |
The shape of the carbon (lV) oxide molecule is A. pyramidal B. linear C. angular D. tetrahedral |
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5. |
Which of the following molecules is held together by hydrogen bond? A. CH4 B. HBr C. H2SO4 D. HF |
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6. |
The bond formed between two elements with electron configurations 1s2 2s2 2p6 3s2 and 1s2 2s2 2p4 is A. metallic B. covalent C. dative D. ionic |
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7. |
The constituent of air that acts as a diluent is A. nitrogen B. carbon (IV) oxide C. noble gases D. oxygen |
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8. |
Steam changes the colour of anhydrous cobalt (ll) chloride from A. white to red B. blue to white C. blue to pink D. white to blue |
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9. |
An example of a hygroscopic substance is A. CuO (S). B. MgCL2(S). C. CaCL2(S). D. NaOH(S). |
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10. |
The solvent used for removing grease stain is A. turpentine B. ammonia solution C. ethanol D. solution of borax in water |
1. |
The presence of an impurity in substance will cause the melting point to A. be zero B. reduce C. increase D. be stable Detailed SolutionImpurities disrupt the repeating pattern of forces that holds the solid together. So a smaller amount of energy is required to melt the part of the solid surrounding the impurity. If less energy is required, then this explains the melting point depression (lowering) observed from impure solids. The more impure the solid is, the more the structure is disrupted and the greater the variation in intermolecular forces in different areas of the solid.There is an explanation video available below. |
|
2. |
What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen? A. 5 dm 3 B. 20 dm 3 C. 15 dm 3 D. 10 dm 3 |
|
3. |
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is A. carbon-14 B. phosphorus-32 C. cobalt-60 D. iodine-131 |
|
4. |
The shape of the carbon (lV) oxide molecule is A. pyramidal B. linear C. angular D. tetrahedral |
|
5. |
Which of the following molecules is held together by hydrogen bond? A. CH4 B. HBr C. H2SO4 D. HF |
6. |
The bond formed between two elements with electron configurations 1s2 2s2 2p6 3s2 and 1s2 2s2 2p4 is A. metallic B. covalent C. dative D. ionic |
|
7. |
The constituent of air that acts as a diluent is A. nitrogen B. carbon (IV) oxide C. noble gases D. oxygen |
|
8. |
Steam changes the colour of anhydrous cobalt (ll) chloride from A. white to red B. blue to white C. blue to pink D. white to blue |
|
9. |
An example of a hygroscopic substance is A. CuO (S). B. MgCL2(S). C. CaCL2(S). D. NaOH(S). |
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10. |
The solvent used for removing grease stain is A. turpentine B. ammonia solution C. ethanol D. solution of borax in water |