41. When $$C{O_2}$$ is bubbled through a solution of barium peroxide in water
A
carbonic acid is formed
B
$${H_2}{O_2}$$ is formed
C
$${H_2}O$$ is formed
D
barium hydroxide is formed
Answer :
$${H_2}{O_2}$$ is formed
42. Which physical property of dihydrogen is wrong ?
A
Odourless gas
B
Tasteless gas
C
Colourless gas
D
Non–inflammable gas
Answer :
Non–inflammable gas
43. Which of the following statements is correct?
A
On a mass for mass basis dihydrogen can release more energy than petrol.
B
Hydrogen economy is the transportation and storage of energy in the form of liquid or gaseous dihydrogen.
C
Advantage of hydrogen economy is that energy is transmitted in the form of dihydrogen and not as electric power.
D
All of these.
Answer :
All of these.
44.
Match the column I with column II and mark the appropriate choice.
Column I
Column II
a.
Clark's method
1.
$$N{a_6}{P_6}{O_{18}}$$
b.
Calgon's method
2.
$$N{a_2}A{l_2}S{i_2}{O_8} \cdot x{H_2}O$$
c.
Ion-exchange method
3.
$$RS{O_3}H$$
d.
Synthetic resins method
4.
$$Ca{\left( {OH} \right)_2}$$
A
a - 1, b - 3, c - 4, d - 2
B
a - 2, b - 3, c - 4, d - 1
C
a - 3, b - 2, c - 1, d - 4
D
a - 4, b - 1, c - 2, d - 3
Answer :
a - 4, b - 1, c - 2, d - 3
45. Which of the following statements is correct ?
A
Hydrogen has same $$IP$$ as alkali metals
B
Hydrogen has same electronegativity as halogens
C
Hydrogen has oxidation number of - 1 and + 1
D
Hydrogen will not be liberated at anode.
Answer :
Hydrogen has oxidation number of - 1 and + 1
46. The process used for the removal of hardness of water is
A
Baeyer
B
Calgon
C
Hoope
D
Serpeck
Answer :
Calgon
47. Which of the following reactions is an example of use of water gas in the synthesis of other compounds?
A
\[C{{H}_{4\left( g \right)}}+{{H}_{2}}{{O}_{\left( g \right)}}\xrightarrow[Ni]{1270\,K}C{{O}_{\left( g \right)}}+{{H}_{2\left( g \right)}}\]
B
\[C{{O}_{\left( g \right)}}+{{H}_{2}}{{O}_{\left( g \right)}}\xrightarrow[\text{Catalyst}]{673\,K}C{{O}_{2\left( g \right)}}+{{H}_{2\left( g \right)}}\]
C
\[{{C}_{n}}{{H}_{2n+2}}+n{{H}_{2}}{{O}_{\left( g \right)}}\xrightarrow[Ni]{1270\,K}\] \[nCO+\left( 2n+1 \right){{H}_{2}}\]
D
\[C{{O}_{\left( g \right)}}+2{{H}_{2\left( g \right)}}\xrightarrow[\text{Catalyst}]{\text{Cobalt}}C{{H}_{3}}O{{H}_{\left( l \right)}}\]
Answer :
\[C{{O}_{\left( g \right)}}+2{{H}_{2\left( g \right)}}\xrightarrow[\text{Catalyst}]{\text{Cobalt}}C{{H}_{3}}O{{H}_{\left( l \right)}}\]
48. What is the trend of boiling points of hydrides of $$N,O$$ and $$F?$$
A
Due to lower molecular masses $$N{H_3},{H_2}O$$ and $$HF$$ have lower boiling points than those of the subsequent group member hydrides.
B
Due to higher electronegativity of $$N, O$$ and $$F;N{H_3},{H_2}O$$ and $$HF$$ show hydrogen bonding and hence higher boiling points than the hydrides of their subsequent group members.
C
There is no regular trend in the boiling points of hydrides.
D
Due to higher oxidation states of $$N, O$$ and $$F,$$ the boiling points of $$N{H_3},{H_2}O$$ and $$HF$$ are higher than the hydrides of their subsequent group members.
Answer :
Due to higher electronegativity of $$N, O$$ and $$F;N{H_3},{H_2}O$$ and $$HF$$ show hydrogen bonding and hence higher boiling points than the hydrides of their subsequent group members.
49.
Given below are two reactions of water with sodium and carbon dioxide. What is the nature of water in these reactions?
$$\left( {\text{i}} \right)2Na + 2{H_2}O \to 2NaOH + {H_2}$$
$$\left( {{\text{ii}}} \right)6C{O_2} + 12{H_2}O \to $$ $${C_6}{H_{12}}{O_6} + 6{H_2}O + 6{O_2}$$
A
In (ii) water acts as an oxidising agent and in (i) it acts as a reducing agent.
B
In (i) water acts as an oxidising agent while in (ii) it acts as a reducing agent.
C
In both (i) and (ii), hydrogen acts as a reducing agent.
D
In both (i) and (ii), hydrogen acts as an oxidising agent.
Answer :
In (i) water acts as an oxidising agent while in (ii) it acts as a reducing agent.
50.
Choose the correct statement about the given figures.
A
(II) represents solid state while (III) represents liquid state.
B
(II) represents liquid state while (III) represents solid state.
C
(I) represents solid state while (III) represents liquid state.
D
(I) represents liquid state while (III) represents solid state.
Answer :
(II) represents liquid state while (III) represents solid state.