Laboratory Method of Hydrogen Gas Preparation

Q.

What is the downward displacement of water?

Q. Zinc granules are used in laboratory preparation of hydrogen because it consists of _____ which acts as a catalyst and speeds up the rate of reaction.

1. calcium
2. copper
3. silver
4. iron

Q.

What is the common name of potassium hydroxide:-

1. Soda ash
2. Caustic soda
3. Caustic potash
4. Lunar caustic

Q.

Why are the following metals not used in the lab. preparation of hydrogen ?

(a) calcium (b) iron (c) aluminium (d) sodium

Q.

Give reasons :

(a) Hydrogen is collected by the downward displacement of water and not of air, even though it is lighter than air.

(b) A candle brought near the mouth of a jar containing hydrogen gas starts burning but is extinguished when pushed inside the jar.

(c) Oxy-hydrogen flame is used for welding and cutting metals.

(d) Apparatus for laboratory preparation of hydrogen should be air tight and away from a naked flame.

Q. Air dissolved in water contains a higher percentage of oxygen

Q.

Pure zinc is not used for preparation of hydrogen. Why?

Q.

Is Potash Alum poisonous?

Q. Which among the following can be used to remove sulphur dioxide gas during the purification of hydrogen gas?

1. Dry gas
2. Caustic potash solution
3. Silver nitrate solution
4. Lead nitrate solution

Q.

Give reason for the following

1. Nitric acid in the dilute form is not used in the laboratory preparation of hydrogen from metals.

2. Granulated zinc is preferred to metallic zinc in the preparation of hydrogen using dilute acid.

3. Hydrogen and alkali metals of group [1A] react with copper [II] oxide to give copper.

4. Hydrogen is collected by the downward displacement of water and not even though it is lighter than air.

5. A Mixture of hydrogen and chlorine can be separated by passage through a porous pot

Q.

Which gas oxygen or nitrogen gets liquified first on cooling air

Q.

why cant u use calcium with dil sulphuric acid to prepare hydrogen in labrotory method

Q.

Which of the following metals does not give hydrogen with acids?

1. Copper

2. Iron

3. Magnesium

4. Zinc

Q.

In laboratory preparation of Hydrogen, $H_{2}S$ is removed from the obtained gas by passing it through:

1. Silver nitrate solution

2. Lead nitrate solution

3. Anhydrous Calcium chloride

4. Caustic potash Solution

Q.

Hydrogen chloride gas gives white precipitate with:

1. Silver nitrate and lead nitrate

2. Sodium nitrate and aluminium nitrate

   and

   Ammonium nitrate and potassium nitrate

3. Sodium nitrate and aluminium nitrate

4. Ammonium nitrate and potassium nitrate

Q.

Give two physical and chemical properties of oxygen.

Q. There are some impurities found during the preparation of hydrogen in the laboratory.
$\left(b\right)$ How can these impurities be removed ?

Q.

Flushing oil tankers with nitrogen increases the chance of explosion.

1. True
2. False

Q. Complete the reaction :- Al + H2SO4 --->

Q.

Mention the acceptable level of Hydrogen sulfide.

Q. Non-metals like sulphur, phosphorous get oxidized by _________ to form their respective acids.

1. concentrated nitric acid
2. all of the above
3. dilute hydrochloric acid
4. concentrated sulphuric acid

Q.

An active metal reacts with water to produces:

1. An Acid

2. Oxygen

3. A Base

Q. Granulated zinc is preferred to metallic zinc in the preparation of hydrogen using dilute acid.

Q. Which of the following metal (is/are) soluble in aqua-regia?

1. Pt
2. Hg
3. Au
4. All of these

Q. Zinc granules are used in laboratory preparation of hydrogen because it consists of _____ which acts as a catalyst and speeds up the rate of reaction.

1. calcium
2. copper
3. silver
4. iron