A silver coin weighing 11.34 g was dissolved in nitric acid. When sodium chloride was added to the solution all the silver (present as $AgN{O}_3$) was precipitated as silver chloride. The weight of the precipitated silver chloride was 14.35 g. Calculate the percentage of silver in the coin.

1. 4.8%

2. 95.2%

3. 90%

4. 80%

Rearrange the following (I to IV) in the order of increasing masses:

(I)   0.5 mole of O₃
(II)  0.5 gm atom of oxygen
(III) 3.011$\times$10²³ molecules of O₂
(IV)  5.6 liter of CO₂ at STP

It is known that an atom contains protons, neutrons, and electrons. If the mass of the neutron is assumed to be half of its original value, and that of the proton is assumed to be twice its original value, then the atomic mass of ${}_6{}^{14}\mathrm{C}$ will:

Nitric acid can be produced ${\mathrm{NH}}_3$ in three steps process

(I) $4N{H}_3\left(g\right) + 5O_2\left(g\right)\to 4NO\left(g\right) + 6H_{2}O\left(g\right)$
(II) $2NO\left(g\right) + O_2\left(g\right)\to 2N{O}_2\left(g\right)$
(III) $3N{O}_2\left(g\right) + H_{2}O\left(l\right) \to 2HN{O}_3\left(aq\right) + NO\left(g\right)$

percent yield Ist, IInd and IIIrd are respectively 50%, 60% and 80% respectively then what volume of $N{H}_3\left(g\right)$ at 1 atm and 0$°$C required to produces 1575 g of $HN{O}_3$

1. 156.25

2. 350 L

3. 3500 L

4. None of these

The density of dry air containing only ${\mathrm{N}}_2$ and ${\mathrm{O}}_2$ is 1.15 g/L at 740 mm and 300 K. What is the percentage
composition of ${\mathrm{N}}_2$ by weight in the air?

In preparation of iron from haematite $\left(F{e}_2{O}_3\right)$by the reaction with carbon:
                          $F{e}_2{O}_3 + C \to Fe + C{O}_2$
How much 80% pure iron could be produced from 120 kg of 90% pure $F{e}_2{O}_3$?

1. 94.5 kg

2. 60.48 kg

3. 116.66 kg

4. 120 kg

A gaseous mixture of ${\mathrm{H}}_2$ and ${\mathrm{CO}}_2$ gas contains 66 mass % of ${\mathrm{CO}}_2$. The vapour density of the mixture is:

1.  6.1

2.  5.4

3.  2.7

4.  10.8

How much volume of 75% alcohol by weight (d=0.80 g/cm³) is required to prepare 150 cm³ of 30% alcohol by weight (density = 0.90 g/cm³)?

The average atomic mass of magnesium is 24.31 a.m.u. Magnesium consists of three isotopes: \(^{24}Mg\), \(^{25}Mg \), and \(^{26}Mg\). The mole percentage of \(^{24}Mg\) is 79%, and the remaining 21% is a mixture of \(^{25}Mg \) and \(^{26}Mg\).
Calculate the mole percentage of \(^{26}Mg\).

1.  10 %
2.  11 %
3.  15 %
4.  16 %

A mixture of $N{H}_{4}N{O}_3 and (N{H}_4{)}_{2}HP{O}_4$ contain 30.40% mass per cent of nitrogen. What is the mass ratio of the two components in the mixture?

1. 2 : 1

2. 1 : 2

3. 3 : 4

4. 4 : 1