Introduction to Oxidation and Reduction

Q.

In an Alkaline medium ${\mathrm{KMnO}}_4$ reacts as follows: $2{\mathrm{KMnO}}_4+2\mathrm{KOH}\to 2{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{H}}_2\mathrm{O}+\mathrm{O}$. Find the Equivalent weight of ${\mathrm{KMnO}}_4$

Q. The order of increasing Oxidation number of $S$ in $S_8,S_2{O}_8^{2-},S_2{O}_3^{2-},S_4{O}_6^{2-}$ is:

1. $S_8<S_2{O}_8^{2-}<S_2{O}_3^{2-}<S_4{O}_6^{2-}$
2. $S_2{O}_8^{2-}<S_2{O}_3^{2-}<S_4{O}_6^{2-}<S_8$
3. $S_2{O}_8^{2-}<S_8<S_4{O}_6^{2-}<S_2{O}_3^{2-}$
4. $S_8<S_2{O}_3^{2-}<S_4{O}_6^{2-}<S_2{O}_8^{2-}$

Q. The value of x in the partial redox equation
$Mn{O}_4^{-}+8H^{+}+xe=M{n}^{2+}+4H_{2}O$ is

1. 5

2. 3

3. 1

4. 0

Q. Equivalent mass of $KMn{O}_4$ in acidic, basic and neutral are in the ratio of :
(Given, molecular mass of $KMn{O}_4=158g$)

1. $3:5:15$
2. $5:3:1$
3. $5:1:3$
4. $3:15:5$

Q. In basic medium, $Cr{O}_4^{2-}$ oxidize $S_2{O}_3^{2-}$ to form $S{O}_4^{2-}$ and itself changes to $Cr(OH{)}_4^{-}.$ How many mL of 0.154 M $Cr{O}_4^{2-}$ are required to react with 40 mL of 0.246 M $S_2{O}_3^{2-}$ ?

1. 200 mL
2. 156.4 mL
3. 170.4 mL
4. 190.4 mL

Q. For a cell involving one electron $E_{cell}^o=0.59Vat298K,$ the equilibrium constant for cell reaction is :

$[\text{Given that}\frac{2.303RT}{F}=0.059VatT=298K]$

(NEET-2019)

1. $1.0\times {10}^2$
2. $1.0\times {10}^5$
3. $1.0\times {10}^{30}$
4. $1.0\times {10}^{10}$

Q. $12\text{g}$ of $Mg$ will react completely with a monoprotic acid to give:

1. 5 moles of $H_2$
2. 1 mole of acid
3. 1/2 mole of $H_2$
4. 1 mole of $O_2$

Q. 100 ml of each of $0.5NNaOH,\frac{N}{5}HCl$ and $\frac{N}{10}{H}_{2}S{O}_4$ are mixed together. The resulting solution will be

1. Acidic
2. Neutral
3. Alkaline
4. None

Q. In the reaction $NaOH+H_{3}P{O}_4\to N{a}_{2}HP{O}_4+H_{2}O$, the equivalent weight of $H_{3}P{O}_4$ (phosphoric acid) is:

1. 98
2. 49
3. 32.66
4. 24.5

Q. What is the sum of oxidation numbers of oxygen and hydrogen in $O_2$ and $H_2$ respectively?

1. $-1$
2. $0$
3. Can't be predicted
4. $+2$

Q. Calculate the weight of $N{a}_{2}C{O}_3$ of 85% purity required to prepare to neutralize 45.6 mL of 0.235 N $H_{2}S{O}_4$ ?

1. 2.05 g
2. 1.44 g
3. 0.25 g
4. 0.67 g