A gaseous compound is composed of 85.7% by mass carbon and 14.3% by mass hydrogen. It's density is 2.28 g/litre at 300 K and 1.0 atm pressure. Determine the molecular formula of the compound:

1.  ${\mathrm{C}}_2{\mathrm{H}}_2$

2.  ${\mathrm{C}}_2{\mathrm{H}}_4$

3.  ${\mathrm{C}}_4{\mathrm{H}}_8$

4.  ${\mathrm{C}}_4{\mathrm{H}}_{10}$

Calculate the % of free ${\mathrm{SO}}_3$ in oleum (a solution of ${\mathrm{SO}}_3$ in ${\mathrm{H}}_2{\mathrm{SO}}_4$) that is labelled 109% ${\mathrm{H}}_2{\mathrm{SO}}_4$.

1. 40

2. 30

3. 50

4. None

100 mL of 10% NaOH (w/V) is added to 100 mL of 10% HCl (w/V). The resultant solution becomes:

1. Alkaline

2. Strongly alkaline

3. Acidic

4. Neutral

1.44 gram of titanium (At. wt. =48) reacted with excess of ${\mathrm{O}}_2$ and produce x gram of non-stoichiometric compound ${\mathrm{Ti}}_{1.44} \mathrm{O}.$ 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 ${\mathrm{Fe}}_2{\mathrm{O}}_3 \left(\mathrm{s}\right) \stackrel{}{\to } {\mathrm{Fe}}_3{\mathrm{O}}_4 \left(\mathrm{s}\right) + {\mathrm{O}}_2 \left(\mathrm{g}\right)$ (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; 
$2Fe{(NO_3)}_3 + 3Na_2CO_3 \rightarrow Fe_2{(CO3)}_3 + 6NaNO_3$
Initially if 2.5 mole of $Fe{(NO_3)}_3$ and 3.6 mole of $Na_2CO_3$ is taken. If 6.3 mole of $NaNO_3$ is obtained then % yield of given reaction is:

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

The impure 6 g of $\mathrm{NaCl}$ is dissolved in water and then treated with excess of silver nitrate solution. The weight of precipitate of silver chloride is found to be 14 g. The % purity of $\mathrm{NaCl}$ solution would be:

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