Preparation of Hydrogen

Q. (b) Give an example of a double displacement reaction, where gas is evolved.

Q.

Water-gas is a mixture of hydrogen and____.

Q.

Which of the following metals on reaction with water releases hydrogen gas?

1. Sodium

2. Mercury

3. Copper

4. Gold

Q.

Which of the following will not produce hydrogen gas?

1. Electrolysis of NaCl in Nelson's cell

2. Reaction of Zn with concentrated H₂SO₄

3. Electrolysis of mildly acidified water

4. Reaction of Zn with NaOH

Q.

What makes it easy to remove dissolved gases from liquids by heating?

Q.

Which of the following statements are correct regarding the process of electrolysis of water?

1. ${\text{H}}^{+}$ ions move towards the cathode.

2. ${\text{OH}}^{-}$ ions move toward the anode.

3. Oxygen gas evolves at the cathode.

4. Hydrogen gas evolves at the cathode.

Q. In the reaction of granulated zinc with sulphuric acid, the copper present as impurity in the zinc acts as a/ an .

1. catalyst
2. inhibitor
3. heat source

Q. Nitric acid $\left(HN{O}_3\right)$ is not used in the manufacture of $H_2$ gas because it is a strong .

1. oxidising agent
2. reducing agent
3. dehydrating agent

Q. Which of the following metals can displace zinc from its solution?

1. Cu
2. Al
3. Fe
4. Ag

Q. Explain the action of acids on non metals

Q. On the basis of the information available from the reaction : 1 2 Al2O3, G 827KJmol 3 2 Al O 3 4 + = of O2, the minimum e.m.f. required to carry out electrolysis of Al2O3 is (F = 96500 C mol1) (1) 2.14 V (2) 4.28 V (3) 6.42 V (4) 8.56 V How to find value of n?

Q.

Producer gas is

1. 

2. 

3. 

4. 

Q. Which gas is evolved at the anode during electrolysis of water?

1. Oxygen
2. Hydrogen
3. Chlorine
4. Nitrogen

Q. ___ is the process of conversion of a gas into solid without undergoing liquid state transition.

1. Freezing
2. Boiling
3. Deposition
4. Condensation

Q.

(a) What happens when an acid reacts with a metal? Give the chemical equation of the reaction involved.

(b) Which gas is usually liberated when an acid reacts with a metal?

Q. Match the following metals with the reason for not producing hydrogen gas on reaction with acids.

1. Very high reactivity
2. Very expensive
3. Impure gas fromation
4. Salt formation

Q. During the electrolysis NaCl solution, how many electrons are lost by each chloride ion?

1. Four
2. Three
3. Two
4. One

Q.

What is the catalyst 'y' used in the water gas shift reaction?

Reaction 1: C(red hot coke) + $\underset{\text{Water gas}}{H_{2}O}$(g) $\stackrel{1273K}{⟶}$ $CO\left(g\right)+H_2\left(g\right)$

Reaction 2: $CO\left(g\right)+H_2\left(g\right)+H_{2}O\left(g\right)$ $\stackrel{y\left(catalyst\right)}{⟶}C{O}_2\left(g\right)+2H_2\left(g\right)$

1. Fe₂O₃/Cr₂O₃

2. V₂O₅

3. Ziegler Natta Catalyst

4. Raney Ni

Q.

In the electrolysis of acidulated water, _______ gas is evolved at the anode.

1. Hydrogen

2. Nitrogen

3. Oxygen

4. Hydrogen Sulphide

Q. Name the gases liberated at anode and cathode respectively when aqueous solution of $NaCl$ is electrolysed.

Q. Match the chemicals with the impurities they remove during the purification of impure $H_2$ gas.

1. $H_{2}S$
2. $P{H}_3$
3. $C{O}_2$

Q.

Highly pure hydrogen (99.9% ) can be obtained from:

1. All of the above

2. Electrolysis of heavy water

3. Electrolysis of water

4. Reacting Zn with Dil H₂SO₄

Q. Sodium, calcium, magnesium, and zinc were taken in 4 test tubes having dilute hydrochloric acid. In which test tube the rate of reaction will be faster?

1. Test tube having zinc
2. Test tube having sodium
3. Test tube having magnesium
4. Test tube having calcium

Q.

$\begin{array}{cc}\text{List I}& \text{List II}\\ \text{A.}B{i}^{3+}⟶(BiO{)}^{+}& \text{p. Heat}\\ \text{B.}[Al{O}_2{]}^{-}⟶Al(OH{)}_3& \text{q. Hydrolysis}\\ \text{C.}Si{O}_4^{4-}⟶S{i}_2{O}_7^{6-}& \text{r. Acidification}\\ \text{D.}\left(B_4{O}_7^{2-}\right)⟶B(OH{)}_3& \text{s. dilution by water}\end{array}$

1. A – q B – r C – p D –q, r

2. A – r B – q C – p D –q, r

3. None of the above

4. A – q, r B – q C – q D –q

Q.

Match Column1 with Column 2

$\begin{array}{cc}\text{Column 1}& \text{Column 2}\\ \text{(i) Sodium}& \left(1\right)\text{Do not react stream}\\ \text{(ii) Aluminium}& \left(2\right)\text{Replace hydrgen}\\ & \text{from steam when red}\\ & \text{hot}\&\text{form respective}\\ & \text{oxides}\\ \text{(iii) Iron}& \left(3\right)\text{Replace hydrogen}\\ & \text{from steam only when}\\ & \text{metals are heated}\\ \text{(iv) Silver}& \left(4\right)\text{Replace hydrogen}\\ & \text{from cold water and}\\ & \text{produce their respective}\\ & \text{hydroxides}\end{array}$

1. (i)-(2), (ii)- (3), (iii)-(1), (iv)-(4)

2. (i)-(1), (ii)-(2), (iii)-(3), (iv)-(4)

3. (i)-(4), (ii)-(3), (iii)-(4), (iv)-(1)

4. (i)-(1), (ii)-(4), (iii)-(2), (iv)-(3)

Q. Calculate the oxidation number of magnesium in potassium permanganate.​

Q.

what is the chemical fomu;a of ferric chloride and what is the formu;a of ferrous chloride?

Q. Why are the following metals not used in the lab preparation of hydrogen:
(d) Sodium?

Q.

Which of the following pair will not produce dihydrogen gas?

1. $\text{Cu + HCl}$ (dil)

2. ${\text{Fe +H}}_2{\text{SO}}_4$ (dil)

3. $\text{Na + alcohol}$

4. $\text{Mg + steam}$

Q. Mention few applications of electrochemistry. (2 marks)