2 gm limestone (CaCO₃ + Impurities ) is reacted with 100ml N/2 HCl. The excess acid requires 60ml N/2 NaOH. The % purity of limestone is

1. 25%

2. 50%

3. 75%

4. 100%

1.575 gm crystalline oxalic acid $\underset{\mathrm{COOH}}{\overset{\mathrm{COOH}}{| }}·{\mathrm{xH}}_2\mathrm{O}$ is dissolved in water and diluted upto 250 ml. 25ml of this solution is completely neutralised with 250ml N/10 NaOH. The value of 'x' is 

1. Zero

2. 1

3. 2

4. 5

A 2 gm mixture of K₂CO₃ and KCl is completely reacted with 100 ml N/10 HCl. The % of K₂CO₃ in the mixture is (K = 39, Cl =35.5, C=12, O=16)

1. 69%

2. 34.5%

3. 50%

4. 100%

400 ml M/10 H₂SO₄ is mixed with 600 ml N/10 NaOH then normality and nature of solution respectively will be

1. 0.02N, basic

2. 0.02N, acidic

3. 0.046N, acidic

4. 0.142N , acidic

The oxidation number of sulphur in S₈, S₂F₂ and H₂S respectively are :

1. 0, +1 and -2

2. +2, +1 and -2

3. 0, +1 and +2

4. -2. +1 and -2

When Cl₂ is converted into Cl^- & Cl${\mathrm{O}}_3^{-}$ then n-factor of Cl₂ will be:

1. 3/5

2. 5/3

3. 7/2

4. 2

MnO₂ + 4HCl $\to$MnCl₂+2H₂O+Cl₂, the equivalent wt. of HCl will be (M$\equiv$Mol wt of HCl)

1. M

2. M/2

3. 2M

4. M/4

In Na₂S₂O₃, the oxidation number of S is

1. +2

2. +4 & zero

3. +6 & -2

4. +3

Which one of the following acts as a reducing agent only?

1. SO₂

2. HNO₃

3. MnO₂

4. H₂S

Mn${\mathrm{O}}_4^{-}$(aq) + 8H⁺(aq) + 5e^- $\to$Mn²⁺(aq) + 4H₂O(l);${\mathrm{E}}^{°}$=1051V

Cr₂O_7^2-(aq) +14H⁺(aq) + 6e _$\to$2Cr^₃₊(aq) ₊ 7H₂O(l)_{;${\mathrm{E}}^{°}$}=1.38V

Fe³⁺(aq) + e^- _$\to$Fe²⁺(aq);_{${\mathrm{E}}^{°}$}=0.77V

Cl₂(g) + 2e^- _$\to$2Cl^-(aq); _{${\mathrm{E}}^{°}$}= 1.40V

The incorrect statement regarding the quantitative estimation of aqueous  Fe(NO₃)_{2 is -}

1. Mn${\mathrm{O}}_4^{-}$ can be used in aqueous HCl

2. Cr₂O_7^2- can be used in aqueous HCl

3. MnO^-2₄ can be used in aqueous H₂SO₄

4.  Cr₂O_7^2- can be used in aqueous H₂SO₄