351.
Oxyacids of phosphorous and the starting materials for their preparation are given below.
Oxyacid
Materials for preparation
a.
$$HP{O_3}$$
1.
$${P_2}{O_5} + {H_2}{O_2} + {H_2}O$$
b.
$${H_3}P{O_3}$$
2.
$${P_4}{O_{10}} + {H_2}O$$
c.
$${H_3}P{O_4}$$
3.
$${P_2}{O_3} + {H_2}O$$
d.
$${H_3}P{O_5}$$
4.
$${P_4}{O_{10}} + {H_2}S{O_4}$$
Choose the correct answer from the codes given below :
A
a - 4, b - 3, c - 2, d - 1
B
a - 1, b - 3, c - 2, d - 4
C
a - 4, b - 3, c - 1, d - 2
D
a - 2, b - 3, c - 1, d - 4
Answer :
a - 4, b - 3, c - 2, d - 1
352. Identify the incorrect statement among the following
A
$$B{r_2}$$ reacts with hot and strong $$NaOH$$ solution to give $$NaBr$$ and $${H_2}O.$$
B
Ozone reacts with $$S{O_2}$$ to give $$S{O_3}.$$
C
Silicon reacts with $$NaOH(aq)$$ in the presence of air to give $$N{a_2}Si{O_3}$$ and $${H_2}O.$$
D
$$C{l_2}$$ reacts with excess of $$N{H_3}$$ to give $${N_2}$$ and $$HCl.$$
Answer :
$$C{l_2}$$ reacts with excess of $$N{H_3}$$ to give $${N_2}$$ and $$HCl.$$
353. Which of the following elements can be involved in \[p\pi -d\pi \] bonding?
A
Carbon
B
Nitrogen
C
Phosphorus
D
Boron
Answer :
Phosphorus
354.
Fill in the blanks by choosing the appropriate option. The noble gases can form compounds with $$\underline {\left( {\text{i}} \right)} $$ and $$\underline {\left( {{\text{ii}}} \right)} .$$ The mixture of $$\underline {\left( {{\text{iii}}} \right)} $$ and $$\underline {\left( {{\text{iv}}} \right)} $$ is used for respiration by divers.
(i)
(ii)
(iii)
(iv)
(a)
iodine
oxygen
oxygen
argon
(b)
fluorine
oxygen
helium
oxygen
(c)
xenon
platinum
argon
krypton
(d)
helium
oxygen
xenon
argon
A
(a)
B
(b)
C
(c)
D
(d)
Answer :
(b)
355. Hypo is used in photography to
A
reduce $$AgBr$$ grains to metallic silver
B
convert metallic silver to silver salt
C
remove undecomposed silver bromide as a soluble complex
D
remove reduced silver
Answer :
remove undecomposed silver bromide as a soluble complex
356. Group 13 elements show + 1 and + 3 oxidation states. Relative stability of + 3 oxidation state may be given as
A
$$T{l^{3 + }} > I{n^{3 + }} > G{a^{3 + }} > A{l^{3 + }} > {B^{3 + }}$$
B
$${B^{3 + }} > A{l^{3 + }} > G{a^{3 + }} > I{n^{3 + }} > T{l^{3 + }}$$
C
$$A{l^{3 + }} > G{a^{3 + }} > T{l^{3 + }} > I{n^{3 + }} > {B^{3 + }}$$
D
$$A{l^{3 + }} > {B^{3 + }} > G{a^{3 + }} > T{l^{3 + }} > I{n^{3 + }}$$
Answer :
$${B^{3 + }} > A{l^{3 + }} > G{a^{3 + }} > I{n^{3 + }} > T{l^{3 + }}$$
357. Which one has the highest boiling point?
A
$$Kr$$
B
$$Xe$$
C
$$He$$
D
$$Ne$$
Answer :
$$Xe$$
358. In a cyclotrimetaphosphoric acid molecule, how many single and double bonds are present?
A
3 double bonds; 9 single bonds
B
6 double bonds; 6 single bonds
C
3 double bonds; 12 single bonds
D
Zero double bonds; 12 single bonds
Answer :
3 double bonds; 12 single bonds
359. Nitrogen combines with metals to form
A
nitrites
B
nitrates
C
nitrosyl chloride
D
nitrides
Answer :
nitrides
360. For $${H_3}P{O_3}$$ and $${H_3}P{O_4},$$ the correct choice is
A
$${H_3}P{O_3}$$ is dibasic and reducing
B
$${H_3}P{O_4}$$ is diabasic and non-reducing
C
$${H_3}P{O_4}$$ is tribasic and reducing
D
$${H_3}P{O_4}$$ is tribasic and non reducing
Answer :
$${H_3}P{O_3}$$ is dibasic and reducing
