1.44 gram of titanium (At. wt. =48) reacted with excess of ${\mathrm{O}}_2$ and produce x gram of non-stoichiometric compound ${\mathrm{Ti}}_{1.44}<mspace\; width="1em"></mspace>\mathrm{O}.$ The value of x is:

1.  2

2.  1.77

3.  1.44

4.  None of the above

2.0 g sample contain mixture of ${\mathrm{SiO}}_2$ and ${\mathrm{Fe}}_2{\mathrm{O}}_3$, on very strong heating leave a residue weighing 1.96 g. The reaction responsible for loss of weight is ${\mathrm{Fe}}_2{\mathrm{O}}_3<mspace\; width="1em"></mspace>\left(\mathrm{s}\right)<mspace\; width="1em"></mspace>\stackrel{}{\to }<mspace\; width="1em"></mspace>{\mathrm{Fe}}_3{\mathrm{O}}_4<mspace\; width="1em"></mspace>\left(\mathrm{s}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{O}}_2<mspace\; width="1em"></mspace>\left(\mathrm{g}\right)$ (unbalance equation)

What is the percentage by mass of ${\mathrm{SiO}}_2$ in original sample?

1.  10%

2.  20%

3.  40%

4.  60%

For the reaction

2Fe(NO₃)₃ + 3Na₂CO₃ → Fe₂(CO₃)₃ + 6NaNO₃

2.5 moles of Fe(NO₃)₃ are allowed to react with 3.6 moles of Na₂CO₃. If the actual amount of NaNO₃ produced is 6.3 moles, calculate the percentage yield of the reaction.

1. 50

2. 84

3. 87.5

4. 100

0.8 mole of a mixture of CO and CO₂ requires exactly 40 gram of NaOH in a solution for complete conversion of all the CO₂ into Na₂CO₃. How many moles more of NaOH would it require for conversion into Na₂CO₃, if mixture (0.8 mole) is completely oxidised to CO₂?

1.  0.2

2.  0.6

3.  1

4.  1.5

A 6.0 g impure sample of sodium chloride is dissolved in water and reacted with excess silver nitrate solution. If 14.0 g of silver chloride is formed, determine the percentage purity of NaCl in the sample.

1.  95%

2.  85%

3.  75%

4.  65%

25.4 g of ${\mathrm{I}}_2$ and 14.2 g  of ${\mathrm{Cl}}_2$ are made to react completely to yield a mixture of ICI and ICI₃. The mole of ICI and ICI₃ formed, is respectively -

1. 0.5, 0.2

2. 0.1, 0.1

3. 0.1, 0.3

4. 0.3, 0.4

The vapour density of a mixture containing \(NO_{2}\) and \(N_{2} O_{4}\)  is 38.3. The mole of \(NO_{2}\) in a 100 g mixture is:

[Vapour density = (Molar mass / 2)]

1. 0.437

2. 0.347

3. 0.557

4. 0.663

Copper forms two oxides. For the same amount of copper, twice as much oxygen was used to form first oxide than to form second one. What is the ratio of the valencies of copper in first and second oxides?

1. 2:5

2. 1:6

3. 2:1

4. 1:2

5 mL of a gaseous hydrocarbon was exposed to 30 mL of ${\mathrm{O}}_2$. The resultant gas, on cooling is found to measure 25 mL of which 10 mL is absorbed by NaOH and the remainder by pyrogallol. Determine molecular formula of hydrocarbon. All measurements are made at constant room temperature.

1. CH₄

2. C₂H₂

3. C₃H₄

4. C₂H₄

60 mL of a mixture of nitrous oxide and nitric oxide was exploded with excess of hydrogen. If 38 mL of ${\mathrm{N}}_2$ was formed, calculate the volume of each gas in the mixture. All measurements are made at constant P and T.

1.20 ml +30 ml

2. 44 ml + 16 ml

3. 10 ml+40 ml

4 .25 ml +25 ml