Oxidation and Reduction

Q. What is oxidation number of each S atom in S4O62-?

Q. why is the hydration enthalpy of alkaline earth metal ions greater then that of alkali metal ions?

Q. When sodium reacts with excess of oxygen, oxidation number of oxygen changes from:

1. 0 to -1

2. 0 to -2

3. -1 to -2

4. +1 to -1

Q.

Those reactions in which oxidation and reduction takes place simultaneously are known as

1. Redox reaction

2. Addition reaction

3. Chemical reaction

4. None of the above

Q. 25 C6h6 + o2 --> co2 + h2o, how to balance this redox reaction, using oxidation number method ?

Q.

The algebraic sum of the oxidation number of all the atoms in a compound must be

1. 0

2. -1/2

3. -2

4. 1

Q. Identify the substance oxidised, reduced, oxidising agent and reducing agent for the following reaction-

Q. 47. Is it possible to balance disproportionation redox reaction by oxidation number method?

Q.

Oxidation of nitrites in presence of potassium permanganate results in formation of:

Q. Which of the following reactions are disproportionation reactions?
a) $2C{u}^{+}$ $\to$ $C{u}^{2+}$ + $C{u}^0$

b) $3Mn{O}_4^{2-}$ + $4H^{+}$ $\to$ $2Mn{O}_4^{-}$ +$Mn{O}_2$ + $2H_{2}O$

c) $2KMn{O}_4$ $\stackrel{△}{\to }$ $K_{2}Mn{O}_4$ + $Mn{O}_2$ + $O_2$

d) $2Mn{O}_4^{-}$ + $3M{n}^{2+}$ + $2H_{2}O$ $⟶$ $5Mn{O}_2$ + $4H^{+}$

1. (a) and (b) only
2. (a), (b) and (c)
3. (a), (c) and (d)
4. (a) and (d) only

Q. 13 In the electronic structure of h2so4 , the total no. Of unshared electrons is: 1. 20 2. 16 3. 12

Q. Identify the substance oxidised, reduced, oxidising agent and reducing agent for each of the following reactions :
$P{b}_{\left(s\right)}+Pb{O}_{2\left(s\right)}+2H_{2}S{O}_{4\left(aq\right)}\to 2PbS{O}_{4\left(s\right)}+2H_2{O}_{\left(l\right)}$

Q. 47 Cl2 + x OH = YClo3- + ZH2O +10 electron The coefficient X, Y, and Z are?

Q. Identify the substance oxidised, reduced, oxidising agent and reducing agent for each of the following reactions:

Q. How to calculate total charge on +ve or -ve ions for Eq.wt of salts?

Q. Among the following which is the strongest oxidising agent:

1. $B{r}_2$
2. $F_2$
3. $I_2$
4. $C{l}_2$

Q. If a small Cu rod is placed in an aqueous solution of ferrous salt , then which of the following will be observed? ( E ^0 _{cu^{2+}/cu}= 0.34V ; {E^0}_{Fe^{2+}/Fe}= -0.44V ) (1) Copper will be oxidised (2) Fe^{2+} will be reduced (3) No reaction will take place (4) Fe^{2+ }will be oxidised

Q.

Which of the following is oxidising agent in \( 2Mg +O_2 (g) \longrightarrow 2MgO (s)\)

Q. In O2[PtF6] what will be charge on O2 and how to find it in case if we have to find the bond order of it

Q. In the given reaction P4 + NaOH + H2O PH3 + NaH2PO2 P is reduced or oxidised

Q. Which of the following is/are example(s) of reduction?

1. ${\text{Cl}}_2\text{(g)}+2{\text{e}}^{-}\to 2{\text{Cl}}^{-}$
2. $\text{Mg (s)}\to {\text{Mg}}^{2+}+2{\text{e}}^{-}$
3. ${\text{S}}^{2-}\to \text{S (s)}+2{\text{e}}^{-}$
4. ${\text{Fe}}^{3+}+{\text{e}}^{-}\to {\text{Fe}}^{2+}$

Q. what are the rules to find oxidation no. of an atom which is bonded to nearby atoms by covalent or dative bonds

Q. In $C+H_{2}O⟶CO+H_2,H_{2}O$ acts as

1. Oxidising agent

2. Reducing agent

3. (a) and (b) both

4. None of these

Q. Neutralisation of $HCl\left(aq\right)$ with $NaOH\left(aq\right)$ is an example of a/an reaction.

1. oxidizing
2. reducing
3. redox
4. non-redox

Q. Which one among the following is the strongest reducing agent?
$F{e}^{2+}+2e^{-}\to Fe(-0.44V)$
$N{i}^{2+}+2e^{-}\to Ni(-0.25V)$
$S{n}^{2+}+2e^{-}\to Sn(-0.14V)$
$F{e}^{3+}+e^{-}\to F{e}^{2+}(+0.77V)$

1. $Fe$
2. $F{e}^{2+}$
3. $Ni$
4. $Sn$

Q.

The conversion of K₂Cr₂O₇ into Cr₂ (SO₄)₃ is a process of

1. Reduction

2. Decomposition

3. Oxidation

4. Substitution

Q. In which of the following reaction water acts as oxidising agent :

Q. The compound $Ag{F}_2$ is unstable compound. However, if formed, the compound acts as a very strong oxidising agent. Why ?

Q.

A substance (atom, ion or molecule) which can readily loose electrons to other substances is called

1. a) Oxidising agent

2. b) Reducing agent

3. c) None of them

4. d) both a and b

Q.

Li⁺ and Cs⁺ ions form hydrated ions as [ Li(H₂O)_x]⁺ and [Cs(H₂O)_y]⁺ . Then 'x' and 'y' are related as

1. x < y

2. x > y

3. y > x

4. x = y