Oxyacids of Phosphorus

Q. $H_{3}P{O}_2$ is the molecular formula of an acid of phosphorus, Its name and basicity respectively are

1. phosphorous acid and two
2. hypophosphorous acid and two
3. hypophosphorous acid and one
4. hypophosphoric acid and two

Q. Which of the following can be called as a conjugate acid - base pair?

1. $HCl,NaOH$
2. $H_3{O}^{+}/O{H}^{-}$
3. $H_{2}S/S^{2-}$
4. $H_{2}S{O}_4,HS{O}_4^{-}$

Q. What is the equivalent mass of $H_{2}S{O}_4$ for the given reaction?
(Molar mass is given as ‘M’)
$H_{2}S{O}_4+NaOH\to NaHS{O}_4+H_{2}O$

1. $\frac{M}{4}$
2. $\frac{M}{2}$
3. $\frac{M}{1}$
4. $\frac{M}{3}$

Q. The order of the oxidation state of the phosphorous atom in $H_{3}P{O}_2,H_{3}P{O}_4,H_{3}P{O}_3$ and $H_4{P}_2{O}_6$ is:

1. $H_{3}P{O}_3>H_{3}P{O}_2>H_{3}P{O}_4>H_4{P}_2{O}_6$
2. $H_{3}P{O}_4>H_{3}P{O}_2>H_{3}P{O}_3>H_4{P}_2{O}_6$
3. $H_{3}P{O}_4>H_4{P}_2{O}_6>H_{3}P{O}_3>H_{3}P{O}_2$
4. $H_{3}P{O}_2>H_{3}P{O}_3>H_4{P}_2{O}_6>H_{3}P{O}_4$

Q. Orthophosphoric acid can dimerize on dehydration - True or False?

1. False
2. True

Q. Molecular weight of $KMn{O}_4$ in acidic medium and neutral medium will be respectively :

1. $7\times \text{equivalent weight and}2\times \text{equivalent weight}$
2. $5\times \text{equivalent weight and}3\times \text{equivalent weight}$
3. $4\times \text{equivalent weight and}5\times \text{equivalent weight}$
4. $2\times \text{equivalent weight and}4\times \text{equivalent weight}$

Q.

$Othophosphoricacid\underset{{220}^{\circ }C}{\overset{gentleheat}{\to }}X$.

What is(are) correct about X?

1. It is tetrabasic.

2. It contains one $P-O-P$ bond.

3. It is dibasic.

4. On hydrolysis, it produces metaphosphoric acid.

Q. Orthophosphoric acid is a __-basic acid.

Q. $H_{3}P{O}_2$ is the molecular formula of an acid of phosphorus, Its name and basicity respectively are

1. phosphorous acid and two
2. hypophosphorous acid and two
3. hypophosphorous acid and one
4. hypophosphoric acid and two

Q.

$Othophosphoricacid\underset{{220}^{\circ }C}{\overset{gentleheat}{\to }}X$.

What is(are) correct about X?

1. It is tetrabasic.

2. It contains one $P-O-P$ bond.

3. It is dibasic.

4. On hydrolysis, it produces metaphosphoric acid.

Q. A waxy white solid is burnt in air (with an excess supply of air) in an extraordinarily exothermic reaction. The product of this reaction rapidly undergoes complete hydrolysis to yield an acid X. The acid X is:

1. Hypophosphorus acid
2. Phosphorous acid
3. Fluorapatite or Phosphorite
4. Orthophosphoric acid

Q. What is the total number of atoms or groups surrounding each phosphorus atom in its oxoacids?

Q. Orthophosphoric acid is completely ioinised in _____steps.

1. 1
2. 2
3. 3
4. 4

Q. The number of $S=O$ bonds present in sulphurous acid, peroxodisulphuric acid and pyrosulphuric acid, respectively are:

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1. $1,4\text{and}3$
2. $2,3\text{and}4$
3. $2,4\text{and}3$
4. $1,4\text{and}4$

Q. The order of the oxidation state of the phosphorous atom in $H_{3}P{O}_2,H_{3}P{O}_4,H_{3}P{O}_3$ and $H_4{P}_2{O}_6$ is:

1. $H_{3}P{O}_3>H_{3}P{O}_2>H_{3}P{O}_4>H_4{P}_2{O}_6$
2. $H_{3}P{O}_4>H_{3}P{O}_2>H_{3}P{O}_3>H_4{P}_2{O}_6$
3. $H_{3}P{O}_4>H_4{P}_2{O}_6>H_{3}P{O}_3>H_{3}P{O}_2$
4. $H_{3}P{O}_2>H_{3}P{O}_3>H_4{P}_2{O}_6>H_{3}P{O}_4$

Q. In a cyclotrimetaphosphoric acid molecule, how many pi and sigma bonds are present?

1. 3 pi bonds; 9 sigma bonds
2. 6 pi bonds; 6 sigma bonds
3. 3 pi bonds; 15 sigma bonds
4. 3 pi bonds; 12 sigma bonds

Q. The basicity of $H_{3}P{O}_2$ is ___

Q. $N{H}_2-N{H}_2$ serves as

1. Chelating ligand
2. Bridging ligand
3. Both (a) and (b).
4. Monodentate ligand

Q. Concentrated orthophosphoric acid is a syrupy, viscous liquid and this is due to __ bonding.

Q. Two tautomeric forms of phosphorus acid are:

1. 
2. 
3. 
4.