Q: Strong reducing behaviour of \$H_3PO_2\$ is due to:

Strong reducing behavior of \$H_3PO_2\$ is due to the presence of one - OH group and two P - H bonds.The reducing properties of oxyacids of phosphorous are due to the presence of P-H bond. It has high tendency to release protons. Thus exhibits reducing nature. Hence, the correct option is \$C\$.

Q: For \$H_3PO_3\$ and \$H_3PO_4\$ the correct choice is:

\$H_3PO_3\$ is a dibasic acid as it has 2 number of replaceable \$OH\$ groups(Dibasic) attached to phosphorous. The oxyacids of phosphorous are reducing agents.\$H_3PO_3\$ is a good reducing agent than \$H_3PO_4\$ . The reducing nature of these acids is based on the no of hydrogen atoms bonded to the central metal atom. As more number of H attached to phosphorous more is its reducing nature. In the case of \$H_3PO_3\$, there is one \$P-H\$ bond which is responsible for it's reducing character whereas there is no such bonding in case of \$H_3PO_4\$.Hence option \$A\$ is correct.

Q: The oxidation state of P in \$H_{3}PO_{4}\$ is :

We know that oxidation state of \$O= -2, H =+1\$Now, let's assume oxidation state of \$P=x\$So, \$x + 4 \times (-2) + 3\times (+1)=0\$\$\Rightarrow x -8 +3 =0\$\$\Rightarrow x= +5\$Hence the oxidation state of P in \$H_{3}PO_{4}\$ is \$+5\$.Therefore option \$(B)\$ is correct.

Q: The oxoacid of phosphorus having the strongest reducing property is:

The oxoacid of phosphorus with the highest number of \$P-H\$ bond will be the strongest reducing agent.Here \$H_3PO_2\$ contain two \$P-H\$ bond which highest among all the given oxoacids of phosphorus.Thus \$H_3PO-2\$ is the strongest reducing agent among the given oxoacids of phosphorus.

Q: Equivalent weight of \$H_3PO_4\$ in each of the reaction will be respectively:\$ H_3PO_4 + OH^- \rightarrow H_2PO_4^- + H_2O\$\$ H_3PO_4 + 2OH^- \rightarrow HPO_4^{2-} + 2H_2O\$\$ H_3PO_4 + 3OH^- \rightarrow PO_4^{3-} + 3H_2O\$

\$Equivalent \ weight = \dfrac{Molecular \ weight }{Number \ of\ Equivalents}\$In case of:\$H_3PO_4 + OH^− \rightarrow H_2PO^−_4+H_2O\$\$H^+\$ ions given = 1Thus the number of equiv\$ = 1\$\$Equivalent \ weight = \dfrac{98}{1} = 98\$In case of:\$H_3PO_4 + 2OH^− \rightarrow HPO^{2−}_4+ 2H_2O\$\$H^+\$ ions given = 2Thus the number of equiv\$ = 2\$\$Equivalent \ weight = \dfrac{98}{2} = 49\$ In case of:\$H_3PO_4 + 3OH^− \rightarrow PO^{3−}_4+ 3H_2O\$\$H^+\$ ions given = 3Thus the number of equiv\$ = 3\$\$Equivalent \ weight = \dfrac{98}{3} = 32.67\$

Q: Which of the correct statement for the given acids?

Phosphinic acid is a monoprotic acid as it contains one \$P-OH\$ bond while phosphonic acid is a diprotic acid as it contains two \$P-OH\$ bonds.

Q: The basicity of phosphoric acid is:

The basicity of phosphoric acid, \$H_3PO_4\$ is 3. Basicity is the number of acidic hydrogen atoms in the molecule. For hydrogen to be acidic, it must be attached to a strongly electronegative atom such as oxygen or fluorine.Hence option C is correct.

Q: Which of the following is a tetrabasic acid?

Tetrabasic acid means acids having \$4-\$ replacable hydrogen atoms.\$H_3PO_2\longrightarrow\$ hypophosphorus acidMetaphosphoric acid\$\longrightarrow (HPO_3)_n\$Pyrophosphoric acid \$\longrightarrow H_4P_2O_7\$Orthophosphoric acid \$\longrightarrow H_3PO_4\$Here, pyrophosphoric acid, \$H_4P_2O_7\$ have \$4\$ removable \$H^+\$ ions, hence is a tetrabasic.

Question 1

Strong reducing behaviour of $H_3PO_2$ is due to:

Accepted Answer

Strong reducing behavior of $H_3PO_2$ is due to the presence of one - OH group and two P - H bonds.The reducing properties of oxyacids of phosphorous are due to the presence of P-H bond. It has high tendency to release protons. Thus exhibits reducing nature. Hence, the correct option is $C$.

Question 2

For $H_3PO_3$ and $H_3PO_4$ the correct choice is:

Accepted Answer

$H_3PO_3$ is a dibasic acid as it has 2 number of replaceable $OH$ groups(Dibasic) attached to phosphorous. The oxyacids of phosphorous are reducing agents.$H_3PO_3$ is a good  reducing agent than $H_3PO_4$ . The reducing nature of these acids is based on the no of hydrogen atoms bonded to the central metal atom. As more number of H attached to phosphorous more is its reducing nature. In the case of $H_3PO_3$, there is one $P-H$ bond which is responsible for it's reducing character whereas there is no such bonding in case of $H_3PO_4$.Hence option $A$ is correct.

Question 3

In a cyclotrimetaphosphoric acid molecule, how many single and double bonds are present?

Accepted Answer

Based on the above structure of cyclotrimetaphosphoric acid there are 3&#10;double bonds; 12 single bonds are present.Hence option C is correct.

Question 4

The oxidation state of P in $H_{3}PO_{4}$ is :

Accepted Answer

We know that oxidation state of $O= -2, H =+1$Now, let's assume oxidation state of $P=x$So, $x + 4 \times (-2) + 3\times (+1)=0$$\Rightarrow x -8 +3 =0$$\Rightarrow x= +5$Hence the oxidation state of P in $H_{3}PO_{4}$ is $+5$.Therefore option $(B)$ is correct.

Question 5

The number of P-O-P bond in cyclic metaphosphoric acid is :

Accepted Answer

The number of P-O-P bond in cyclic metaphosphoric acid is three.

Question 6

The oxoacid of phosphorus having the strongest reducing property is:

Accepted Answer

The oxoacid of phosphorus with the highest number of $P-H$ bond will be the strongest reducing agent.Here $H_3PO_2$ contain two $P-H$ bond which highest among all the given oxoacids of phosphorus.Thus $H_3PO-2$ is the strongest reducing agent among the given oxoacids of phosphorus.

Question 7

Equivalent weight of $H_3PO_4$ in each of the reaction will be respectively:$ H_3PO_4  +  OH^-  \rightarrow H_2PO_4^- + H_2O$$ H_3PO_4 +  2OH^-  \rightarrow HPO_4^{2-} + 2H_2O$$ H_3PO_4 +  3OH^-  \rightarrow PO_4^{3-} + 3H_2O$

Accepted Answer

$Equivalent \ weight = \dfrac{Molecular \ weight }{Number \ of\ Equivalents}$In case of:$H_3PO_4 + OH^&#8722; \rightarrow H_2PO^&#8722;_4+H_2O$$H^+$ ions  given = 1Thus the number of equiv$ = 1$$Equivalent \ weight = \dfrac{98}{1} = 98$In case of:$H_3PO_4 + 2OH^&#8722; \rightarrow HPO^{2&#8722;}_4+ 2H_2O$$H^+$ ions given = 2Thus the number of equiv$ = 2$$Equivalent \ weight = \dfrac{98}{2} = 49$ In case of:$H_3PO_4 + 3OH^&#8722; \rightarrow PO^{3&#8722;}_4+ 3H_2O$$H^+$ ions given = 3Thus the number of equiv$ = 3$$Equivalent \ weight = \dfrac{98}{3} = 32.67$

Question 8

Which of the correct statement for the given acids?

Accepted Answer

Phosphinic acid is a monoprotic acid as it contains one $P-OH$ bond while phosphonic acid is a diprotic acid as it contains two $P-OH$ bonds.

Question 9

The basicity of phosphoric acid is:

Accepted Answer

The basicity of phosphoric acid, $H_3PO_4$ is 3. Basicity&#10;is the number of acidic hydrogen atoms in the molecule. For hydrogen to be&#10;acidic, it must be attached to a strongly electronegative atom such as oxygen&#10;or fluorine.Hence option C is correct.

Question 10

Which of the following is a tetrabasic acid?

Accepted Answer

Tetrabasic acid means acids having $4-$ replacable hydrogen atoms.$H_3PO_2\longrightarrow$ hypophosphorus acidMetaphosphoric acid$\longrightarrow (HPO_3)_n$Pyrophosphoric acid $\longrightarrow H_4P_2O_7$Orthophosphoric acid $\longrightarrow H_3PO_4$Here, pyrophosphoric acid, $H_4P_2O_7$ have $4$ removable $H^+$ ions, hence is a tetrabasic.

Other Properties of Oxoacids of Phosphorus

Language

Rate

REVISE WITH CONCEPTS

Oxoacids of Phosphorus

QUICK SUMMARY WITH STORIES

Oxoacids of Phosphorous

Strong reducing behaviour of $H_{3} P O_{2}$ is due to:

For $H_{3} P O_{3}$ and $H_{3} P O_{4}$ the correct choice is:

In a cyclotrimetaphosphoric acid molecule, how many single and double bonds are present?

The oxidation state of P in $H_{3} P O_{4}$ is :

The number of P-O-P bond in cyclic metaphosphoric acid is :

The oxoacid of phosphorus having the strongest reducing property is:

Equivalent weight of $H_{3} P O_{4}$ in each of the reaction will be respectively:

$H_{3} P O_{4} + O H^{-} \to H_{2} P O_{4}^{-} + H_{2} O$
$H_{3} P O_{4} + 2 O H^{-} \to H P O_{4}^{2 -} + 2 H_{2} O$
$H_{3} P O_{4} + 3 O H^{-} \to P O_{4}^{3 -} + 3 H_{2} O$

Which of the correct statement for the given acids?

The basicity of phosphoric acid is:

Which of the following is a tetrabasic acid?

Other Properties of Oxoacids of Phosphorus

Language

Rate

REVISE WITH CONCEPTS

Oxoacids of Phosphorus

QUICK SUMMARY WITH STORIES

Oxoacids of Phosphorous

Strong reducing behaviour of H3​PO2​ is due to:

For H3​PO3​ and H3​PO4​ the correct choice is:

In a cyclotrimetaphosphoric acid molecule, how many single and double bonds are present?

The oxidation state of P in H3​PO4​ is :

The number of P-O-P bond in cyclic metaphosphoric acid is :

The oxoacid of phosphorus having the strongest reducing property is:

Equivalent weight of H3​PO4​ in each of the reaction will be respectively: H3​PO4​+OH−→H2​PO4−​+H2​O H3​PO4​+2OH−→HPO42−​+2H2​O H3​PO4​+3OH−→PO43−​+3H2​O

Which of the correct statement for the given acids?

The basicity of phosphoric acid is:

Which of the following is a tetrabasic acid?

Strong reducing behaviour of $H_{3} P O_{2}$ is due to:

For $H_{3} P O_{3}$ and $H_{3} P O_{4}$ the correct choice is:

The oxidation state of P in $H_{3} P O_{4}$ is :

Equivalent weight of $H_{3} P O_{4}$ in each of the reaction will be respectively:

$H_{3} P O_{4} + O H^{-} \to H_{2} P O_{4}^{-} + H_{2} O$
$H_{3} P O_{4} + 2 O H^{-} \to H P O_{4}^{2 -} + 2 H_{2} O$
$H_{3} P O_{4} + 3 O H^{-} \to P O_{4}^{3 -} + 3 H_{2} O$