Page 192 - Chemistry ICSE Class IX

180 ICSE Chemistry – 9

ASSIGNMENT 3

Ideal gas equation, Universal gas constant, Aq. tension, Standard temperature and pressure

ϭ͘ tƌŝƚĞ ĚŽǁŶ ƚŚĞ ĞdžƉƌĞƐƐŝŽŶ ĨŽƌ ĂŶ ŝĚĞĂů ŐĂƐ ĞƋƵĂƟŽŶ͘
Ϯ͘ Ž ŝĚĞĂů ŐĂƐĞƐ ĞdžŝƐƚ͍ tƌŝƚĞ ĚŽǁŶ ƚŚĞ ŝĚĞĂů ŐĂƐ ĞƋƵĂƟŽŶ ĂŶĚ ĚĞƐĐƌŝďĞ ĞĂĐŚ ƉĂƌĂŵĞƚĞƌ ǁŚŝĐŚ ĂƉƉĞĂƌƐ ŝŶ ƚŚĞ ĞƋƵĂƟŽŶ͘
ϯ͘ ĞƌŝǀĞ ƚŚĞ ĞƋƵĂƟŽŶ͕ PV = n RT ďLJ Ă ƐŝŵƉůĞ ŵĞƚŚŽĚ͘
ϰ͘ tŚĂƚ ŝƐ ƚŚĞ ǀĂůƵĞ ŽĨ ƚŚĞ ĐŽŶƐƚĂŶƚ R͕ ǁŚŝĐŚ ĂƉƉĞĂƌƐ ŝŶ ƚŚĞ ŐĂƐ ĞƋƵĂƟŽŶ͍
ϱ͘ tŚĂƚ ŝƐ ŵĞĂŶƚ ďLJ ĂƋƵĞŽƵƐ ƚĞŶƐŝŽŶ͍ ,Žǁ ŝƐ ƚŚĞ ƉƌĞƐƐƵƌĞ ĞdžĞƌƚĞĚ ďLJ Ă ŐĂƐ ĐŽƌƌĞĐƚĞĚ ĨŽƌ ĂƋƵĞŽƵƐ ƚĞŶƐŝŽŶ͍
ϲ͘ ĂůĐƵůĂƚĞ ƚŚĞ ǀŽůƵŵĞ ŽĨ ĚƌLJ Ăŝƌ Ăƚ ^dW ƚŚĂƚ ŽĐĐƵƉŝĞƐ Ϯϴ ŵ> Ăƚ ϭϰΣ ĂŶĚ ϳϱϬ ŵŵ ,Ő ǁŚĞŶ ƐĂƚƵƌĂƚĞĚ ǁŝƚŚ ǁĂƚĞƌ ǀĂƉŽƵƌ͘ dŚĞ
ǀĂƉŽƵƌ ƉƌĞƐƐƵƌĞ ŽĨ ǁĂƚĞƌ Ăƚ ϭϰΣ ŝƐ ϭϮ ŵŵ ,Ő͘ [Ans. Ϯϱ͘ϵ ŵ>΁
ϳ͘ ĐĞƌƚĂŝŶ ŵĂƐƐ ŽĨ Ă ŐĂƐ ŽĐĐƵƉŝĞƐ Ă ǀŽůƵŵĞ ŽĨ Ϯ > Ăƚ ϮϳΣ ĂŶĚ ϭϬϬ WĂ͘ &ŝŶĚ ƚŚĞ ƚĞŵƉĞƌĂƚƵƌĞ ǁŚĞŶ ƚŚĞ ǀŽůƵŵĞ ĂŶĚ ƉƌĞƐƐƵƌĞ
ďĞĐŽŵĞ ŚĂůĨ ŽĨ ƚŚĞŝƌ ŝŶŝƟĂů ǀĂůƵĞƐ͘ [Ans. ʹϭϵϴΣ ΁
ϴ͘ ϭϬϬ ŵ> ŽĨ ŶŝƚƌŽŐĞŶ ĐŽůůĞĐƚĞĚ Ăƚ ϮϳΣ ĂŶĚ ϳϮϬ ŵŵ ,Ő ŝƐ ĐŽŽůĞĚ ƚŽ ʹϳϯΣ ƵŶĚĞƌ Ă ƉƌĞƐƐƵƌĞ ŽĨ ϳϲϬ ŵŵ ,Ő͘ tŚĂƚ ŝƐ ƚŚĞ
ǀŽůƵŵĞ ŽĐĐƵƉŝĞĚ ďLJ ƚŚĞ ŐĂƐ͍ [Ans. ϲϯ͘Ϯ ŵ>͘΁
ϯ
–2
ϵ͘ Ϭ͘ϭϰϱ Ěŵ ŽĨ ŚLJĚƌŽŐĞŶ ŐĂƐ ŝƐ ĐŽůůĞĐƚĞĚ ŽǀĞƌ ǁĂƚĞƌ Ăƚ Ă ƚĞŵƉĞƌĂƚƵƌĞ ŽĨ ϮϯΣ ĂŶĚ ƚŽƚĂů ƉƌĞƐƐƵƌĞ ŽĨ ϵϵϬϴϱ E ŵ ͘ /Ĩ ƚŚĞ
–2
ǀĂƉŽƵƌ ƉƌĞƐƐƵƌĞ ŽĨ ǁĂƚĞƌ Ăƚ ϮϯΣ ŝƐ Ϯϵϳϯ E ŵ ͕ ǁŚĂƚ ŝƐ ƚŚĞ ƉƌĞƐƐƵƌĞ ĞdžĞƌƚĞĚ ďLJ ƚŚĞ ĚƌLJ ŐĂƐ͍ ůƐŽ ĐĂůĐƵůĂƚĞ ƚŚĞ ǀŽůƵŵĞ ŽĨ
–2
ϯ
ĚƌLJ ŐĂƐ ƵŶĚĞƌ ϭ Ăƚŵ ƉƌĞƐƐƵƌĞ͘ [Ans. ϵϲϭϭϮ E ŵ ͖ Ϭ͘ϭϯϳ Ěŵ ΁
Let us Answer Some More Questions
1. Mention three characteristics of gases.
2. Write the SI units of mass, volume, pressure and temperature.
3. State Boyle’s law.

4. Draw a graph of Volume vs 1/Pressure for three different temperatures.
5. Write the mathematical equation for Charles’ law.
6. How is the temperature on Kelvin scale related to that on the Celsius scale?
7. What are NTP conditions? Are NTP and STP conditions the same?
8. Write the mathematical equation for Boyle’s law.
9. Mention one application each of Boyle’s law and Charles’ law.
10. Using Charles’ law equation show that the volume of a gas becomes zero at –273°C.
11. Mention an application of the ideal gas equation.
12. How is the pressure of gas corrected for the presence of water vapour in it?

13. Draw the following graphs for an ideal gas:
(a) Pressure vs 1/Volume
(b) Pressure × Volume vs Pressure
(c) Pressure vs Volume
14. From Charles’ law, derive the value of zero degree on Kelvin scale.
15. Derive ideal gas equation.

16. Calculate the value of the universal gas constant.
17. What is meant by standard temperature and pressure?
18. Tick (9) the correct answer.
(i) The measurable parameter of gases which depends on pressure under constant temperature is