Gay Lussac's Law, Avagadro's Law

Q. The volume of a drop of water is $0.05\text{mL}$ and the density of water is $1.0\text{g/mL}$. How many water molecules are present in a drop of water?

1. $1.7\times {10}^{21}$
2. $5.4\times {10}^{23}$
3. $2.2\times {10}^{26}$
4. $1.71\times {10}^{20}$

Q.

Which of the following has the smallest number of molecules?

1. $22\mathrm{g}$ of ${\mathrm{CO}}_2$ gas

2. $11.2\mathrm{L}$ of ${\mathrm{CO}}_2$ gas

3. $22.4\times {10}^3\mathrm{mL}$ of ${\mathrm{CO}}_2$ gas

4. $0.1\mathrm{mole}$ of ${\mathrm{CO}}_2$ gas

Q.

How do you calculate the number of moles from volume?

Q.

One liter of ${\mathrm{CO}}_2$ is passed through red hot coke. The volume becomes 1.4 litres at same temperature and pressure. The composition of the products is ____.

Q.

Calculate the number of molecules in $4\mathrm{g}$ of oxygen.

Q. The density of air is $0.001293{\text{g/cm}}^3$ at STP. Which of the following statements is/are correct?

1. Vapour density is $14.48$
2. Molecular weight is $28.96$ amu
3. Vapour density is $0.001293$
4. Vapour density and molecular weight cannot be determined

Q.

Hydrogen gas is prepared in the laboratory by reacting dilute$\mathrm{HCl}$ with granulated zinc. The following reaction takes place: $\mathrm{Zn}+2\mathrm{HCl}\to {\mathrm{ZnCl}}_2+{\mathrm{H}}_2$ Calculate the volume of hydrogen gas is liberated at STP when $32.65\mathrm{g}$of Zinc reacts with$\mathrm{HCl}$ . 1 mole of a gas occupies $22.7\mathrm{L}$ volume at STP; atomic mass of $\mathrm{Zn}=65.3\mathrm{u}?$

1. $10.03\mathrm{L}$

2. $11.35\mathrm{L}$

3. $11.57\mathrm{L}$

4. $9.53\mathrm{L}$

Q.

Compute the number of ions present in 5.85 g of sodium chloride.

Q.

The number of Carbon atoms in 1g of CaCO₃ is:

1. 6.02×10²³

2. 6.02×10²¹

3. 3.0125×10²²

4. 1.204×10²³

Q.

What is the definition of a perfect gas?

Q.

The number of atoms present in $1.6\text{g}$ of methane is

1. $6.02\times {10}^{23}$

2. $3.01\times {10}^{24}$

3. $3.01\times {10}^{23}$

4. $6.02\times {10}^{24}$

Q.

$108\mathrm{g}$ silver (molar mass $108\mathrm{g}{\mathrm{mol}}^{-1}$) is deposited at cathode from ${\mathrm{AgNO}}_3\left(\mathrm{aq}\right)$solution by a certain quantity of electricity. The volume (in $\mathrm{L}$) of oxygen gas produced at $273\mathrm{K}$ and $1\mathrm{bar}$ pressure from water by the same quantity of electricity is:

Q.

Illustrate the law of definite proportions from the following data:-1)0.32g of sulphur on burning in air produced 224ml of SO2 at N.T.P

Q.

45.4 L of dinitrogen reacted with 22.7 L of dioxygen and 45.4 L of nitrous oxide was formed. The reaction is given below

$2N_2\left(g\right)+O_2\left(g\right)\to 2N_{2}O\left(g\right)$

Which law is being obeyed in this experiment? write the statement of the law?

Q. The ratio of volumes occupied by $1$ mole of $O_2$ and $1$ mole $C{O}_2$ under identical conditions of temperature and pressure is

1. $1:2$
2. $1:3$
3. $1:1$
4. $2:1$

Q. 5.6 litres of a gas at NTP is found to have a mass of 11 g.
The molecular mass of the gas is:

1. 44 g
2. 36 g
3. 11.4 g
4. 16 g

Q.

A gas of mass 32 gms has a volume of 20 litres at S.T.P .Calculate the gram molecular weight of the gas.

Q. A sample of water gas has a composition by volume of 50% $H_2$, 45% $CO$ and 5% $C{O}_2$. Calculate the volume in litres at STP at which the water gas on treatment with excess of steam will produce 5 L of $H_2$. The equation for the reaction is: $CO+H_{2}O\to C{O}_2+H_2$

1. $5.26\text{L}$
2. $2.33\text{L}$
3. $5.00\text{L}$
4. $7.20\text{L}$

Q.

A sample of Vitamin C is known to contain $2.58\times {10}^{24}$ oxygen atoms. How many moles of oxygen atoms are present in the sample?

Q. Which of the following represents Avogadro’s hypothesis?

1. Gases react together in volumes which bear a simple ratio to one another.
2. Equal volumes of all gases under the same conditions of temperature and pressure contain an equal number of molecules.
3. Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compounds.
4. Equal volumes of all gases under the same temperature and pressure conditions contain an equal number of atoms.

Q.

Calculate the number of particles in $0.1\mathrm{mol}$ of carbon atoms.

Q. The density of potassium bromide crystal is $2.75gc{m}^{-3}$ and the length of a unit cell is $654pm$. What will be the crystal lattice of $KBr$?

$\text{Molar mass of}KBr=119gmo{l}^{-1}$

1. Face centred cubic
2. Body centred cubic
3. Simple cubic
4. Edge centred cubdic

Q.

ammonia contains 82.35% of nitrogen and 17.65% of hydrogen , water contains 88.90% of oxygen and 11.10% of Hydrogen. Nitrogen trioxide contains 63.15% of oxygen and 36.85% of nitrogen. Show that this data illustrate the law of Reciprocal proportion.

Q.

Define a molecule. How many molecules are present in

(a) 9 gram of water

(b) 17 gram of ammonia

Q.

What is the SI unit used to measure the amount of substance?

Q. The density of a unit cell $\text{in}\left(g/c{m}^3\right)$ can be represented as :
Here,
$a\text{is the edge length in}pm$
$Z_{eff}\text{is the effective number of particles in a unit cell}$
$M\text{is the molar mass}{N}_A\text{is the avogadro number}$

1. $\frac{M}{N_A\times a^3\times {10}^{-30}\times Z_{eff}}$
2. $\frac{Z_{eff}\times M}{N_A\times a^3\times {10}^{-30}}$
3. $\frac{N_A\times a^3\times {10}^{-30}}{Z_{eff}\times M}$
4. $\frac{N_A\times a^3\times {10}^{-30}\times Z_{eff}}{M}$

Q. { The vapour pressure of }n -hexane at }350K is }840 torr }}{ and that of cyclohexane is }600 torr. Mole fraction of }}{ hexane in the mixture that boils at }350K and }1 atm }} pressure assuming ideal behaviour is

Q. An element exists in bcc lattice with a cell edge of $300pm$. Calculate the molar mass if density of the unit cell is $7g//c{m}^3$.
Take $N_A=6\times {10}^{23}$

1. $56.7gmo{l}^{-1}$
2. $5.67gmo{l}^{-1}$
3. $113.4gmo{l}^{-1}$
4. $11.34gmo{l}^{-1}$

Q. $11.2\text{L}$ of $C{H}_4$ and $22.4\text{L}$ of $C_2{H}_6$ at $STP$ are mixed. Then the correct statement(s) is/are:

1. Vapour density of the mixture is 12.67
2. Average molecular weight will be less than 16
3. Average molecular weight will be greater than 16 and less than 30
4. Average molecular weight will be greater than 30

Q. If you are given Avogadro's number of atoms of a gas 'X'. If half of the atoms are converted into $X_{\left(g\right)}^{+}$ by energy $\Delta H$. The IE of X is

1. $\frac{2\Delta H}{N_A}$
2. $\frac{2N_A}{\Delta H}$
3. $\frac{\Delta H}{2N_A}$
4. $\frac{N_A}{\Delta H}$