Tag: introduction to hydrogen

Questions Related to introduction to hydrogen

Which of the following has highest calorific value?

chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

  1. Animal fat

  2. Hydrogen gas

  3. Gasoline

  4. Coal

Show answer
Correct Option: B
Explanation:

Animal fat: 38kJ/g
Coal: 29.3kJ/g
Hydrogen gas: 142kJ/g
Gasoline: 48kJ/g

The usage of dihydrogen is:

chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

  1. It acts a a fuel cell

  2. Energy is distributed in the form of dihydrogen

  3. It is economical fuel

  4. All of the above

Show answer
Correct Option: D
Explanation:

Dihydrogen fuel is a zero-emission fuel when burned with oxygen (if one considers water not as an emission) or used in a contained cell. The energy released enables hydrogen to act as a fuel. In an electrochemical cell, that energy can be used with relatively high efficiency.

How many atoms of oxygen are present in the compound $ K _4Al _2 (SO _4) _3.24H _2O? $

chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

  1. 40

  2. 36

  3. 32

  4. 31

Show answer
Correct Option: B

Hydrogen gas is:

chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

  1. has high molecular weight.

  2. a medium for storage of energy

  3. excellent fuel

  4. both B and C

Show answer
Correct Option: D
Explanation:

Hydrogen is not found in pure form on Earth, however, so it must be produced from other compounds such as natural gas, biomass, alcohols or water. In all cases it takes energy to convert these into pure hydrogen. For that reason, hydrogen is really an energy carrier or storage medium rather than an energy source in itself.

Basic principle of hydrogen economy is:

chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

  1. transportation of energy in the form of liquid or gaseous dihydrogen

  2. storage of energy in the form of liquid or gaseous dihydrogen

  3. both $A$ and $B$

  4. none of the above

Show answer
Correct Option: C
Explanation:

The usage of hydrogen as a low-carbon energy source, such as gasoline as a transport fuel, it is referred to as "Hydrogen economy". The basic principles of Hydrogen economy are:-

(i) Storage of energy in the form of liquid or gaseous dihydrogen.
(ii) transportation of energy in the form of liquid or gaseous dihydrogen.
Thus the answer is both (A) and (B).

In which of the following reactions hydrogen gas is liberated ?

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. $C{H _3}COOH + Na$

  2. $C{H _3}COOH + NaHC{O _3}$

  3. $C{H _3}COOH + NaOH$

  4. $C{H _3}COOH + {H _2}O.$

Show answer
Correct Option: C

Brass gets discoloured in air because of the presence of which of the following gases in air  ?

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1.  Hydrogen sulphide

  2.  Oxygen

  3.  Nitrogen

  4. Carbon dioxide

Show answer
Correct Option: A
Explanation:

 Hydrogen sulphide

Metals like .......... , ........... and .......... give $H _2$ with steam.

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. iron

  2. magnesium

  3. aluminium

  4. sodium

  5. calcium

  6. none of the above

Show answer
Correct Option: A,B,C
Explanation:

Metals which react with steam to give $H _2$ gas are Iron, Magnesium and Aluminium.


Magnesium ribbon reacts with steam to give Magnesium oxide and Hydrogen gas.

$Mg$ $+$ $H _2O$ $=$ $MgO$ $+$ $H _2$

Aluminium reacts with steam to give Aluminium Oxide and Hydrogen gas. But the reaction takes place very slowly, as a layer of Aluminium Oxide forms on the metal.

$2Al$ $+$ $3H _2O$ $=$ $Al _2O _3$ $+$ $3H _2$
Iron does not react with cold water. It reacts with steam to form Ferric Oxide and hydrogen gas.

$3Fe$ $+$ $4H _2O$ $=$ $Fe _3O _4$ $+$ $4H _2$
Thus, options A, B  and C are correct.

Sodium ________ reacts vigorously with cold water.

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. metal

  2. amalgam

  3. in the molten state

  4. none of the above

Show answer
Correct Option: A
Explanation:

Sodium metal is an extremely reactive metal. When sodium metal comes into contact with water, it displaces hydrogen gas as follows:


$2 Na(s) + 2H _2O \rightarrow 2 NaOH(aq) + H _2(g)$

At $298 \, K$ , assuming ideal behaviour, the average kinetic energy of a deuterium molecule is :

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. Two times that of a hydrogen molecule

  2. Four times that of a hydrogen molecule

  3. Half of that of a hydrogen molecule

  4. Same as that of a hydrogen molecule

Show answer
Correct Option: D
Explanation:

Average Kinetic Energy depends only on temperature

$\displaystyle (KE) _{avg} = \frac {3kT} {2} $ per molecule