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All questions of Hydrogen for Class 8 Exam
What is the process called when hydrogen is produced by breaking down water or acids using reactive metals?- a)Catalytic Hydrogenation
- b)Electrolysis
- c)Displacement Reaction
- d)Oxidation
Correct answer is option 'C'. Can you explain this answer?
What is the process called when hydrogen is produced by breaking down water or acids using reactive metals?
a)
Catalytic Hydrogenation
b)
Electrolysis
c)
Displacement Reaction
d)
Oxidation
 | Get Idea answered |
The process is termed a displacement reaction, as more reactive metals displace hydrogen from its compounds like water and dilute acids, leading to the release of hydrogen gas.
Which gas is produced when hydrogen reacts with chlorine?- a)Water
- b)Ammonia
- c)Hydrogen chloride
- d)Methane
Correct answer is option 'C'. Can you explain this answer?
Which gas is produced when hydrogen reacts with chlorine?
a)
Water
b)
Ammonia
c)
Hydrogen chloride
d)
Methane
| | Get Idea answered |
When hydrogen reacts with chlorine gas, it forms hydrogen chloride (HCl). This reaction can be explosive in bright sunlight, showcasing the reactivity of hydrogen with halogens.
What is the significance of liquid hydrogen in modern technology?- a)It is used for making glass.
- b)It is used primarily for cooking.
- c)It is a refrigerant for food preservation.
- d)It serves as a clean fuel for rockets.
Correct answer is option 'D'. Can you explain this answer?
What is the significance of liquid hydrogen in modern technology?
a)
It is used for making glass.
b)
It is used primarily for cooking.
c)
It is a refrigerant for food preservation.
d)
It serves as a clean fuel for rockets.
| | Get Idea answered |
Liquid hydrogen is significant as a clean fuel in rocket propulsion systems. It provides a high-energy output when burned with oxygen, making it an essential component for space exploration missions.
What is the most common element in the universe?- a)Hydrogen
- b)Helium
- c)Oxygen
- d)Carbon
Correct answer is option 'A'. Can you explain this answer?
What is the most common element in the universe?
a)
Hydrogen
b)
Helium
c)
Oxygen
d)
Carbon
| | Get Idea answered |
Hydrogen is the most abundant element in the universe, making up about 90% of all matter. It is primarily found in stars, including our Sun, where it plays a crucial role in energy production through nuclear fusion.
What is the primary component of water gas?- a)Nitrogen and hydrogen
- b)Hydrogen and oxygen
- c)Methane and carbon dioxide
- d)Hydrogen and carbon monoxide
Correct answer is option 'D'. Can you explain this answer?
What is the primary component of water gas?
a)
Nitrogen and hydrogen
b)
Hydrogen and oxygen
c)
Methane and carbon dioxide
d)
Hydrogen and carbon monoxide
| | Get Idea answered |
Water gas is primarily composed of hydrogen and carbon monoxide. It is produced by passing steam over hot carbon (coke), and it serves as a significant source of hydrogen in industrial processes.
Which of the following best describes a redox reaction?- a)No change occurs.
- b)Only reduction occurs.
- c)Only oxidation occurs.
- d)Both oxidation and reduction occur simultaneously.
Correct answer is option 'D'. Can you explain this answer?
Which of the following best describes a redox reaction?
a)
No change occurs.
b)
Only reduction occurs.
c)
Only oxidation occurs.
d)
Both oxidation and reduction occur simultaneously.
| | Get Idea answered |
A redox reaction involves both oxidation (loss of electrons) and reduction (gain of electrons) occurring simultaneously. In the context of hydrogen reactions, it often acts as a reducing agent.
How is hydrogen collected during the electrolysis of water?- a)It cannot be collected
- b)In a separate chamber
- c)At the cathode
- d)At the anode
Correct answer is option 'C'. Can you explain this answer?
How is hydrogen collected during the electrolysis of water?
a)
It cannot be collected
b)
In a separate chamber
c)
At the cathode
d)
At the anode
| | Get Idea answered |
During the electrolysis of water, hydrogen gas is collected at the cathode (negative electrode), while oxygen is collected at the anode (positive electrode). This separation is crucial for utilizing both gases.
What happens when hydrogen burns in oxygen?- a)It produces hydrogen peroxide
- b)It produces ozone
- c)It produces water
- d)It produces carbon dioxide
Correct answer is option 'C'. Can you explain this answer?
What happens when hydrogen burns in oxygen?
a)
It produces hydrogen peroxide
b)
It produces ozone
c)
It produces water
d)
It produces carbon dioxide
| | Get Idea answered |
When hydrogen burns in oxygen, it forms water (H₂O). This reaction is highly exothermic and releases a significant amount of energy, making hydrogen a powerful fuel source.
Which of the following statements is true regarding the activity series of metals?- a)All metals can displace hydrogen.
- b)Metals above hydrogen can displace it from acids.
- c)Metals below hydrogen can displace it from acids.
- d)Hydrogen is not included in the activity series.
Correct answer is option 'B'. Can you explain this answer?
Which of the following statements is true regarding the activity series of metals?
a)
All metals can displace hydrogen.
b)
Metals above hydrogen can displace it from acids.
c)
Metals below hydrogen can displace it from acids.
d)
Hydrogen is not included in the activity series.
| | Get Idea answered |
Metals that are above hydrogen in the activity series are capable of displacing hydrogen from acids, while those below cannot. This series helps predict the outcomes of displacement reactions.
Who first identified hydrogen as a distinct element?- a)Robert Boyle
- b)Henry Cavendish
- c)Paracelsus
- d)Antoine Lavoisier
Correct answer is option 'B'. Can you explain this answer?
Who first identified hydrogen as a distinct element?
a)
Robert Boyle
b)
Henry Cavendish
c)
Paracelsus
d)
Antoine Lavoisier
| | Get Idea answered |
Henry Cavendish is credited with the discovery of hydrogen as a distinct element in 1766, when he referred to it as "inflammable air." His experiments demonstrated its properties, including the fact that it produces water when burned.
Which of the following metals can react with cold water to produce hydrogen?- a)Lead
- b)Magnesium
- c)Copper
- d)Sodium
Correct answer is option 'D'. Can you explain this answer?
Which of the following metals can react with cold water to produce hydrogen?
a)
Lead
b)
Magnesium
c)
Copper
d)
Sodium
| | Get Idea answered |
Sodium is one of the metals that reacts vigorously with cold water to produce hydrogen gas and sodium hydroxide. This reaction is highly exothermic and can be explosive.
What type of reaction occurs when hydrogen is passed over heated copper(II) oxide?- a)Decomposition
- b)Synthesis
- c)Reduction
- d)Oxidation
Correct answer is option 'C'. Can you explain this answer?
What type of reaction occurs when hydrogen is passed over heated copper(II) oxide?
a)
Decomposition
b)
Synthesis
c)
Reduction
d)
Oxidation
| | Get Idea answered |
This is a reduction reaction. Hydrogen reduces copper(II) oxide (CuO) to copper metal by removing oxygen from the oxide, demonstrating hydrogen's strong reducing properties.
In which process is hydrogen used to convert liquid vegetable oils into solid fats?- a)Electrolysis
- b)Catalytic Hydrogenation
- c)Distillation
- d)Combustion
Correct answer is option 'B'. Can you explain this answer?
In which process is hydrogen used to convert liquid vegetable oils into solid fats?
a)
Electrolysis
b)
Catalytic Hydrogenation
c)
Distillation
d)
Combustion
| | Get Idea answered |
Catalytic hydrogenation is the process where liquid vegetable oils are treated with hydrogen under pressure in the presence of catalysts like nickel or palladium to produce solid fats, such as margarine.
What role does hydrogen play in the Haber process?- a)It is one of the reactants.
- b)It is the catalyst.
- c)It is used for cooling.
- d)It is a byproduct.
Correct answer is option 'A'. Can you explain this answer?
What role does hydrogen play in the Haber process?
a)
It is one of the reactants.
b)
It is the catalyst.
c)
It is used for cooling.
d)
It is a byproduct.
| | Get Idea answered |
In the Haber process, hydrogen is one of the primary reactants used to synthesize ammonia from nitrogen. This reaction is essential for producing fertilizers that are vital for agriculture.
Which of the following is a property of hydrogen?- a)It is a dense gas.
- b)It is highly flammable.
- c)It is a strong oxidizing agent.
- d)It supports combustion.
Correct answer is option 'B'. Can you explain this answer?
Which of the following is a property of hydrogen?
a)
It is a dense gas.
b)
It is highly flammable.
c)
It is a strong oxidizing agent.
d)
It supports combustion.
| | Get Idea answered |
Hydrogen is highly flammable and burns readily in air or oxygen, producing water vapor. This property makes it a useful fuel but also necessitates careful handling to avoid explosions.
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