1. Which of the following is the most abundant element in the universe by mass?
Answer:
Explanation:
Hydrogen makes up about 75% of the elemental mass of the universe.
2. Which isotope of hydrogen contains one proton and one neutron?
Answer:
Explanation:
Deuterium has one proton and one neutron in its nucleus.
3. Which of the following forms of hydrogen is radioactive?
Answer:
Explanation:
Tritium is a radioactive isotope of hydrogen.
4. What is the oxidation state of hydrogen in most of its compounds?
Answer:
Explanation:
In most of its compounds, hydrogen is in a +1 oxidation state.
5. The hydrogen obtained from water using electrolysis is:
Answer:
Explanation:
Nascent hydrogen is freshly formed hydrogen which is extremely reactive.
6. Which of the following gases is NOT a diatomic molecule?
Answer:
Explanation:
Argon is a noble gas and exists as single atoms, not diatomic molecules.
7. In which compound is hydrogen present in a -1 oxidation state?
Answer:
Explanation:
In sodium hydride (NaH), hydrogen is in a -1 oxidation state.
8. Which of the following is NOT a property of hydrogen?
Answer:
Explanation:
Hydrogen is lighter than air.
9. The boiling point of liquid hydrogen is:
Answer:
Explanation:
Liquid hydrogen boils at 20 K.
10. Which form of hydrogen has unpaired electrons?
Answer:
Explanation:
Ortho hydrogen has unpaired electrons, while para hydrogen has paired electrons.
11. The process of producing hydrogen gas by reacting hot coke with steam is known as:
Answer:
Explanation:
The Bosch process involves reacting hot coke with steam to produce hydrogen gas.
12. Which of the following compounds is used in hydrogenation of oils?
Answer:
Explanation:
Molecular hydrogen (H2) is used in the hydrogenation of oils to produce fats.
13. Which metal is commonly used as a catalyst in the hydrogenation process?
Answer:
Explanation:
Nickel is commonly used as a catalyst in the hydrogenation of unsaturated fats.
14. Water gas is a mixture of:
Answer:
Explanation:
Water gas is a mixture of carbon monoxide and hydrogen.
15. Which isotope of hydrogen is used as a tracer in biochemical research?
Answer:
Explanation:
Tritium, being radioactive, is used as a tracer in biochemical research.
16. In the electrolysis of water, hydrogen gas is formed at:
Answer:
Explanation:
During the electrolysis of water, hydrogen is released at the cathode.
17. The compound H2O2 is known as:
Answer:
Explanation:
H2O2 is the chemical formula for hydrogen peroxide.
18. Which of the following statements about hydrogen is false?
Answer:
Explanation:
Hydrogen can form both covalent and ionic bonds.
19. The Haber process is used for the commercial preparation of:
Answer:
Explanation:
The Haber process combines nitrogen and hydrogen to produce ammonia.
20. Which form of hydrogen is present in the sun and other stars?
Answer:
Explanation:
Atomic hydrogen is present in high amounts in the sun and other stars.