JAMB Tutorial on Chemistry Part 1 ( Gas Laws- Charles Law)
One of the most important topics for JAMB and Post-JAMB Chemistry students is the Gas Laws.
Gases are substances moving randomly in an enclosed system, they have no Fixed mass as they take the shape of the container they are in.
So on that note, we will go to the Laws governing calculations involving Gaseous Substances.
What is Charles Law’s?
It states that the volume of a given mass of gas is directly proportional to its temperature in kelvin provided that pressure remains constant.
To explain this briefly, it means if the volume is increasing, the temperature will also increase and if the volume of a given gas is decreasing, the temperature also will decrease at the same Rate provided that Pressure is constant.
- Mathematically it means
Volume ~ Temperature (pressure is constant)
~ means variation sign)
V= KT ( by introducing a constant K)
K = V/T
K= V1 = V2
——- ——-
T1 T2
- The volume of a gas is theoretically Zero at -273 Celsius.
Recommended: When Will JAMB Slip Reprinting Start 2024? JAMB Reprint Date
In any question, alwalys remain to convert from Celsius to kelvin.
Here is how to do that:
Kelvin = ( Celsius +273)
Let’s move on to example
1. The volume of a gas in a cylinder is 40cm3 and 0’C. The temperature at which the volume expands to is 54.70cm3 under same pressure is ?
Solution
Start by stating parameters
V1 = 40cm3
T1 = 0’C …… make sure you convert to kelvin
(0+273) = 273K
V2 = 54.70cm3
T2 = ?
V1 = V2
—— ——
T1 T2
40=54.7
—- ——
273 T2
T2 = 273 X 54.7
————-
40
T2 = 373.3K
2. If 60cm3 of a gas is heated from 27’C to 50’C. What is the new volume of the gas at constant pressure?
V1 = 60cm3
T2 = 27’C
Is that all?
Don’t forget to convert to convert to Kelvin
K = 273+27
K = 300’
V2 =?
T2 = 50’C == 323K
V1 = V2
—- ——
T1 T2
V2 = 60 X 323
————-
300
V2 =64.6cm3
- Recommended: JAMB TUTORIAL: PHYICS( GUIDELINES TO MOTION)
That’s all for Part 1, thanks for taking your time to go through this and we hope it is helpful, kindly share.
Attention JAMB candidates! Join the Edustuff JAMB class for 2025 and gain the edge you need to excel in your exams. Click here to join: https://wa.link/sbvfq1.
