Stoichiometric Calculations

Q.

Henrys law constant for $C{O}_2$ in water is $1.6\times {10}^8$ Pa at 298K.

Calculate quantity of $C{O}_2$ in 500 mL of soda water when packed under 2.5 atm $C{O}_2$ pressure at 298K.

Q.

Calculate the mole fraction of benzene in a solution containing 30% by mass of carbon tetrachloride

Q.

The density of a 2.05 M solution of acetic acid in water is 1.02 g/ml. The molality of the solution is:

Q. The mol fraction of benzene in a solution in Toluene is 0.50. calculate the weight percent of benzene in solution.

Q.

Calcium hydroxide reacts with carbon dioxide to form.

1. Calcium carbonate and water.

2. Calcium carbonate and hydrogen.

3. Calcium bicarbonate and water.

4. None of the above.

Q. If $N_A$ is the Avogadro’s number, then the number of valence electrons in $4.2\text{g}$ of nitride ions $\left(N^{3-}\right)$ is:

1. $4.2N_A$
2. $2.4N_A$
3. $1.6N_A$
4. $3.2N_A$

Q.

Benzene and toluene form nearly ideal solution .At 313K the vapour pressure of pure benzene is 150mm Hg and of pure toluene is 50 mm Hg .calculate vapour pressure of mixture of these two containing their equal masses at 313 K .

Q. 3g of H2 react with 29g of O2 to yield H2O.which is the limiting reactant? Calculate the maximum amount of H2O that can be formed. Calculate the amount the reactant which remains unreacted.

Q.

Calculate the mass of 1 atom of nitrogen.

Q.

Translate the following statement into a chemical equation and then balance the equation:

Aluminium metal replaces iron from ferric oxide (Fe₂O₃), giving aluminium oxide and iron.

Q.

Calculate the total number of electrons present in 1.4 g of dinitrogen gas.

Q. 5 moles of $A{B}_2$ weigh $125\times {10}^{-3}kg$ and 10 moles of $A_2{B}_2$ weigh $300\times {10}^{-3}kg$.The molar mass of $A\left(M_A\right)$ and molar mass of $B\left(M_B\right)$ in kg/mol are :

1. $M_A=10\times {10}^{-3}and{M}_B=5\times {10}^{-3}$
2. $M_A=25\times {10}^{-3}and{M}_B=50\times {10}^{-3}$
3. $M_A=5\times {10}^{-3}and{M}_B=10\times {10}^{-3}$
4. $M_A=50\times {10}^{-3}and{M}_B=25\times {10}^{-3}$

Q. The density of a solution prepared by dissolving 120 g of urea (mol. mass = 60 g/mol) in 1000 g of water is 1.15 g/mL. The molarity of this solution is

1. 1.78 M
2. 1.02 M
3. 2.05 M
4. 0.50M

Q.

Caffeine has a molecular weight of 194.If it contains 28.9% by mass of Nitrogen, the number of atoms of Nitrogen in one molecule of caffeine is(pls give an explanation for necessary steps)

Q. What volume of oxygen gas measured at $0^{\circ }C$ and 1 atm pressure is needed to burn 1 L of propane gas completely, measured under the same conditions?

1. 10 L
2. 7 L
3. 6 L
4. 5 L

Q. The number of moles of oxygen in one litre of air containing 21% oxygen by volume, under standard conditions are:

1. $0.186\text{moles}$
2. $0.0093\text{moles}$
3. $0.21\text{moles}$
4. $2.10\text{moles}$

Q. Liquid benzene $\left(C_6{H}_6\right)$ burns in oxygen according to the following equation:
$2C_6{H}_6\left(l\right)+15O_2\left(g\right)\to 12C{O}_2\left(g\right)+6H_{2}O\left(g\right)$
How many litres of oxygen at STP are required for the complete combustion of $39\text{g}$ of liquid benzene?

1. $74\text{L}$
2. $11.2\text{L}$
3. $22.4\text{L}$
4. $84\text{L}$

Q.

The ${\mathrm{NaNO}}_3$ weighed out to make $50\mathrm{mL}$ of an aqueous solution containing$70.0\mathrm{mg}{\mathrm{Na}}^{+}$ per mL is $\mathrm{\_\_\_\_\_\_\_\_}$g.

Q.

If one atom of an element x weigh $6.643\times {10}^{-23}\mathrm{g}$. What will be the number of moles in 20 Kg?

Q. Henrys law constant of CO2 in water at 298 K is 5/3 K bar. Determine its concentration (mole fraction) in rain if CO2 is 1% (by volume) in atmosphere (1 atm = 1bar).

Q. What weight of $CaC{O}_3$ must be decomposed to produce a sufficient quantity of carbon dioxide to convert $21.2\text{g}$ of $N{a}_{2}C{O}_3$ completely into $NaHC{O}_3$. (Molar mass of $Na=23\text{g/mol},Ca=40\text{g/mol}$):
$CaC{O}_3\to CaO+C{O}_2$ $N{a}_{2}C{O}_3+C{O}_2+H_{2}O\to 2NaHC{O}_3$

1. $100\text{g}$
2. $20\text{g}$
3. $120\text{g}$
4. $30\text{g}$

Q.

Average Molecular Mass of ozonised oxygen is 36. Calculate percentage of oxygen in ozonised oxygen

Q.

What is the weight of the residue obtained when $2.76g$ of silver carbonate is strongly heated?

1. $2.16g$

2. $2.46g$

3. $2.32g$

4. $2.64g$

Q. In the reaction, $4N{H}_3+5O_2\to 4NO+6H_{2}O$, when one mole of ammonia and one mole of oxygen are allowed to react till completion, which of the following statements is true?

1. 1.0 mole of $H_{2}O$ is produced
2. All the oxygen is consumed
3. 1.5 mole of $NO$ is formed
4. All the ammonia is consumed

Q.

The equation for the combustion of glucose is: ${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\left(\mathrm{s}\right)+6{\mathrm{O}}_2\left(\mathrm{g}\right)\to 6{\mathrm{CO}}_2\left(\mathrm{g}\right)+6{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$. How many grams of ${\mathrm{H}}_2\mathrm{O}$ will be produced when $8.064\mathrm{g}$ of glucose is burned?

Q.

An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this substance is subjected to complete combustion.

Q. $20.0\text{g}$ of a magnesium carbonate sample decomposes on heating to give carbon dioxide and $8.0\text{g}$ magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample ?
(At. Wt. : $Mg$ = 24)

1. $60$
2. $84$
3. $75$
4. $96$

Q. $K_{2}Hg{I}_4$ is $40\%$ ionised in aqueous solution. The value of its van't Hoff factor (i) is:
(JEE-Main 2019)

1. $2.2$
2. $2.0$
3. $1.6$
4. $1.8$

Q. Calculate the weight of Iron which will be converted into its oxide by the action of 18 g of steam.
Given the reaction :
$3Fe+4H_{2}O\to F{e}_3{O}_4+4H_2$
(Atomic mass of Fe=56 g.

Q.

a) Calculate the mass of ammonia produced if 2.00 ×10³ g of nitrogen reacts with 1.00 ×10³ g.

b) Will any of the two reagents will remain unreacted. If yes, which one and what would be its mass.