Which of the following reactions does not represent a redox change?

1. CaCO₃ $\to$CaO + CO₂

2. 2H₂ + O₂ $\to$2H₂O

3. Na + H₂O $\to$ NaOH + \(\frac{1}{2}\)H₂

4. MnCl₃ $\to$ MnCl₂ + \(\frac{1}{2}\)Cl₂

In which SO₂ acts as oxidant, while reacting with:

1. acidified KMnO₄

2. acidified K₂Cr₂O₇

3. H₂S

4. H₂0₂

Which of the following shows the highest oxidation number in the combined state?

1. Os

2. Ru

3. Xe

4. All of the above

Milliequivalents of a solute in a solution can be given by:

1. Mzeq_. = M x V_{in mL}

2. Meq. = N x V_{in mL}

3. Mzeq. = $\frac{mass}{Eq. mass}\times$1000

4. both 2 and 3

The correct order of reducing power of halide ions is:

1. Cl^- > Br^- > I^- > F^-

2. Cl^- >  I^- > Br^- > F^-

3.  Br^- > Cl^- > I^- > F^-

4.  I^- > Br^- > Cl^- > F^-

The number of peroxide linkages in CrO₅ is /are

1. One

2. Two

3. Three

4. None of the above

1.520g of the hydroxide of a metal on ignition gave 0.995 g of oxide. The equivalent mass of metal is:

1. 1.520

2. 0.995

3. 19.00

4. 9.00

1g of pure calcium carbonate was found to require 50 mL of dilute HCl for complete reactions. The strength of the HCl solution is given by:

1. 4N

2. 2N

3. 0.4N

4. 0.2N

Amongst the following species that have an atom in (+6) oxidation state is-

1. Mn${\mathrm{O}}_4^{-}$

2. Cr$(\mathrm{CN}{)}_6^{3-}$

3. Ni${\mathrm{F}}_6^{2-}$

4. CrO₂Cl₂

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