Viraf J. Dalal solutions for Simplified ICSE Chemistry [English] Class 9 chapter 7 - Study Of Gas Laws [Latest edition]

A fixed volume of a gas occupies 760cm³ at 27°C and 70 cm of Hg. What will be its vol. at s.t.p.

State Boyle's Law.

At 0°C and 760 mm Hg pressure, a gas occupies a volume of 10Q cm³. The Kelvin temperature (Absolute temperature) of the gas is increased by one-fifth while the pressure is increased one and a half times. Calculate the final volume of the gas. [80 cc.]

The pressure on one mole of gas at s.t.p. is doubled and the temperature is raised to 546 K. What is the final volume of the gas ? [one mole of a gas occupies a volume of 22.4 litres at stp.] 

Is it possible to change the temperature and pressure of a fixed mass of a gas without changing its volume? Explain your answer.

When stating the volume of a gas, the pressure and temperature should also be given. Why?

State Boyle's Law.

Express Kelvin Zero in °C

What volume will a gas occupy at 740 mm pressure which at 1480 nun occupies 500 cc? [Temperature being constant]

The volume of a given mass of a gas at 27°C is 100 cc. To what temperature should it be heated at the same pressure so that it will occupy a volume of 150 cc?

A fixed mass of a gas has a volume of 750 cc at—23°C and 800 mm pressure. Calculate the pressure for which its volume will be 720 cc. The temperature being - 3°C.

What temperature would be necessary to double the volume of a gas initially at s.t.p. if the pressure is decreased by 50%?

A gas cylinder having a capacity of 20 litres contains a gas at 100 atmos. How many flasks of 200 cm³ capacity can be filled from it at 1 atmos. pressure if the temperature remains constant?

A certain mass of gas occupied 850 ml at a pressure of 760 mm of Hg. On increasing the pressure it was found that the volume of the gas was 75% of its initial value. Assuming constant temperature, find the final pressure of the gas?

It is required to reduce the volume of a gas by 20% by compressing it at a constant pressure. To do so, the gas has to be cooled. If the gas attains a final temperature of 157°C, find the initial temperature of the gas.

At a given temperature the pressure of a gas reduces to 75% of its initial value and the volume increases by 40% of its initial value. Find this temperature if the initial temperature was -10°C.

Name or state the following:

The law which states that pressure remaining constant the volume of a given mass of dry gas is directly proportional to its absolute [Kelvin] temperature.

Name or state the following:

The law which studies the relationship between pressure of a gas and the volume occupied by it at constant temperature.

Name or state the following:

An equation used in chemical calculations which gives a simultaneous effect of changes of temperature and pressure on the volume of a given mass of dry gas

Name or state the following:

The standard pressure of a gas in cm. of mercury corresponding to one atmospheric pressure.

Name or state the following:

The absolute temperature value corresponding to 35°C.

Give reason for the following:

Gases exert pressure in all directions.

Give reason for the following:

Gases have a lower density compared to solids or liquids.

Give reason for the following:

Temperature remaining constant the product of the vol. & the press, of a given mass of dry gas is a constant.

Give reason for the following:

All temperatures in the absolute (Kelvin) scale is in positive figures.

Give reason for the following:

Volumes of gases are converted into s.t.p. conditions and then compared.

Calculate the following:

Calculate the temperature to which a gas must be heated, so that the volume triples without any change in pressure. The gas is originally at 57”C and having a volume 150 cc.

Calculate the following:

A gas ‘X’ at -33°C is heated to 127°C at constant pressure. Calculate the percentage increase in the volume of the gas.

Calculate the volume of a gas ‘A’ at s.t.p., if at 37°C and 775 mm of mercury pressure, it occupies a volume of `9 1/2` litres.

Calculate the following:

Calculate the temperature at which a gas ‘A’ at 20°C having a volume, of 500 cc. will occupy a volume of 250 cc.

Calculate the following:

A gas ‘X’ is collected over water at 17°C and 750 mm. pressure. If the volume of the gas collected is 50 cc., calculate the volume of the dry gas at s.t.p. [at 17°C the vapour pressure is 14 mm.]

Assuming temperature remaining constant calculate the pressure of the gas in the following:

The pressure of a gas having volume 1000 cc. originally occupying 1500 cc. at 720 mm. pressure.

Assuming temperature remaining constant calculate the pressure of the gas in the following:

The pressure of a gas having volume 100 lits. originally occupying 75 dm³ at 700 mm. pressure.

Assuming temperature remaining constant calculate the pressure of the gas in the following:

The pressure of a gas having volume 380 lits. originally occupying 800 cm³ at 76 cm. pressure.

Assuming temperature remaining constant calculate the pressure of the gas in the following:

The pressure of a gas having volume 1800 ml. originally occupying 300 ml. at 6 atms. pressure.

Assuming temperature remaining constant calculate the pressure of the gas in the following:

The pressure of a gas having volume 1500 cm³ originally occupying 750 cc. at 5 ats. pressure.

Calculate the following:

The temp, at which 500 cc. of a gas ‘X’ at temp. 293K occupies half it’s original volume [pressure constant].

Calculate the following:

The volume at s.t.p. occupied by a gas “Y” originally occupying 760 cc. at 300K and 70 cm. press, of Hg.

Calculate the following:

The volume at s.t.p. occupied by a gas ‘Z’ originally occupying 1.57 dm³ at 310.5K and 75 cm. press. of Hg.

Calculate the following:

The volume at s.t.p. occupied by a gas ‘Q’ originally occupying 153.7 cm³ at 287K and 750 mm. pressure [vapour pressure of gas ‘Q’ at 287K is 12 mm of Hg.]

Calculate the following:

The temperature to which a gas ‘P’ has to be heated to triple it’s volume, if the gas originally occupied 150 cm³ at 330K [pressure remaining constant].

Fill in the blank with the correct word, from the words in option:

If the temperature of a fixed mass of a gas is kept constant and the pressure is increased, the volume correspondingly _______.

Fill in the blank with the correct word, from the words in option:

If the pressure of a fixed mass of a gas is kept constant and the temperature is increased, the volume correspondingly _______

Fill in the blank with the correct word, from the words in option:

1 dm³ of a gas is equal to _______.

Fill in the blank with the correct word, from the words in option:

All the temperature on the kelvin scale are in ____ figures.

Fill in the blank with the correct word, from the words in option:

At -273°C the volume of a gas is theoretically ______.