Charles' Law

Q. An open flask containing air is heated from $300K$ to $500K$ . What percentage of air will be escaped to the atmosphere, if pressure is kept constant?

1. $40$
2. $80$
3. $60$
4. $20$

Q.

A student forgot to add the reaction mixture to the round bottomed flask at ${27}^{\circ }C$ but instead he/she placed the flask on the flame. After a lapse of time, he realized his mistake, and using a pyrometer he found the temperature of the flask was ${477}^{\circ }C$. What fraction of air would have been expelled out?

Q.

A measured temperature on Fahrenheit scale is ${200}^{\circ }F.$ What will this reading be on celsius scale ?

(a) ${40}^{\circ }C$ (b) ${94}^{\circ }C$

(c) ${93.3}^{\circ }C$ (d) ${30}^{\circ }$

Q. The temperature of 5 mL of a strong acid is increased by $5^{\circ }C$ when 5 mL of a strong base is added to it. If 10 mL of each of the same solutions is mixed, the temperature should increase by:

1. ${10}^{\circ }$
2. ${15}^{\circ }$
3. Cannot be predicted
4. $5^{\circ }$

Q.

In terms of Charles' law explain why $–{273}^{\circ }C$ is the lowest possible temperature.

Q. Equal masses of oxygen, hydrogen and methane are taken in container in identical condition. Find the ratio of the volumes of the gases

1. 16:1:8
2. 1:16:2
3. 8:1:16
4. 2:16:1

Q.

An open flask containing air is heated from 300 K to 500 K. What percentage of air will escape to the atmosphere, if pressure is kept constant?

1. 80

2. 40

3. 60

4. 20

Q.

What gives rise pressure to on the gas?

Q. If the temperature of 1 L of a gas is increased from ${27}^{\circ }\text{C}$ to ${57}^{\circ }\text{C}$, find the final volume of the gas, assuming the pressure to be constant.

1. $1.1\text{L}$
2. $2.2\text{L}$
3. $3\text{L}$
4. $0.1\text{L}$

Q. Volume of the air that will be expelled from a vessel of 300 cm³ when it is heated from 27^o C to 37^o C at the same pressure will be

1. 310 cm³
2. 10 cm³
3. 290 cm³
4. 70 cm³

Q.

Freundlich adsorption isotherm is given by the expression $\frac{x}{m}=k{p}^{\frac{1}{n}}$ Which of the following conclusions can be drawn from this expression.

1. When $n=0,\frac{x}{m}vsp$
   graph is a line parallel to $x-axis$

2. When $\frac{1}{n}=0,$ the adsorption is independent of pressure.

3. When $\frac{1}{n}=0,$ the adsorption is directly proportional to pressure .

4. When $n=0,$ plot of
   $\frac{x}{m}vsp$ is a curve.

Q.

The vapour pressure of water at 80^oC is 355 torr. A 100ml vessel contained water-saturated oxygen at 80^oC , the total gas pressure being 760 torr. The contents of the vessel were pumped into a 50ml vessel at the same temperature. What were the partial pressures of oxygen and water vapor? What was the total pressure in the final equilibrium state? Neglect the volume of any water which might condense.

Q.

For any liquid, vapor pressure increases with increase in

1. volume

2. density of liquid

3. external pressure

4. temperature

Q. An open container of volume 3 litre contains air at 1 atmospheric pressure. The container is heated from initial temperature ${27}^{\circ }\text{C}$ to $t^{\circ }\text{C}$, the amount of the gas expelled from the container measured 1.45 litre at ${17}^{\circ }\text{C}$ and 1 atm. Find temperature $t$

Q. A car tyre has a volume of 10 litre when inflated. The tire is inflated to the pressure of 3 atm at 17 degrees celsius with air. due to driving the temperature of tyre increases to 47 degree Celsius.how many litres of air measured at 47 degree Celsius and pressure of 1 atm should be let out to restore the tire to 3 atm at 47 degree Celsius

Q.

How do you calculate standard temperature and pressure?

Q.

How do you find partial pressure from moles?

Q.

A 3g sample of ${\mathrm{Na}}_2{\mathrm{CO}}_3.10{\mathrm{H}}_2\mathrm{O}$ is heated to a constant mass. How much anhydrous salt remains?

Q.

Find the relation between$Y$(adiabatic constant) and degree of freedom $\left(f\right)$.

1. $f=2/\gamma -1$

2. $f=\gamma /\gamma -1$

3. $f=\gamma -1/2$

4. $f=\gamma -1/\gamma$

Q.

The Kelvin scale temperature is $0K$. What is the corresponding Celsius scale temperature?

Q.

Find the relative molecular mass of a gas, 0.546 g of which occupies 360 cm³ at 87°C and 380 mm $\mathrm{Hg}$ pressure. [1 litre of hydrogen at S.T.P weighs 0.09 g]

Q.

A box of 1 L capacity is divided into two equal compartments by a thin partition which are filled with 2g H2 and 16g CH4 respectively. The pressure in each compartment is recorded as P atm. The total pressure when partition is removed will be?

Q.

A rigid vessel of the volume $0.50m^3$ containing H₂​ at $20.50{}^{o}C$ and pressure of $611\times {10}^{3}Pa$ was connected to a second rigid vessel of the volume$0.75m^3$ containing Ar at$31.20{}^{o}C$ at a pressure of $433\times {10}^{3}Pa$. A valve separating the two vessels is opened and both are cooled to a temperature of $14.50{}^{o}C$. What is the final pressure in the vessels?

Q. ntIn case of real gases in P-V graph, below critical temperature, length of horizontal portion of isotherms increases at lower temperatures - why ?n

Q.

The volume occupied by oxygen at STP obtained on heating the 490 g of KClO₃ is 130 L. Calculate the percentage purity of KClO₃ (KClO₃ on heating produces KCl and O₂).

Q. The correct graph among the following given, if $T_1>T_2>T_3$ is:

1. 
2. All of the above
3. 
4. 
   

Q. A gas occupies volume of $580mL$ at $17{}^{o}C.$ It is heated to $100{}^{o}C$ at constant pressure. Calculate the final volume of the gas -

1. $746mL$
2. $760mL$
3. $773mL$
4. $780mL$

Q.

Write short notes on the gas laws.

Q.

There is a temperature at which the reading on the kelvin scale is numerically

1. equal to that on the celsius scale

2. lower than that on the celsius scale

3. less than zero

4. equal to that on the Fahrenheit scale

Q.

If the volume expansion coefficient of a solid is $7.2\times {10}^{-5}{/}^{0}C$. What is the value of its linear expansion coefficient?