Answer:
691.6 mmHg
Step-by-step explanation:
At standard temperature and pressure, temperature of a system = 273K, and pressure= 1atm
T1= 273.15K
P1= 1atm
T2= (–25°C +273.15 )= 248.15K
From Gay-Lussac's law which expressed that at constant volume, pressure of a particular mass of gas is directly proportional to temperature . It can be expressed as
P1 / T1 = P2 / T2
Where P1= initial pressure
T2= final temperature
T1= initial temperature
P2= final pressure
Making P2 subject of the formula
P2= (P1 × T2)/ P1
Substitute the values we have
P2= (1 atm × 248.15K)/273.15
P2= 0.91 atm
But
1atm= 760 mmHg
0.91 atm= X mmHg
If we cross multiply we have
X mmHg= (760× 0.91)/1
= 691.6 mmHg
Hence, the final pressure of the gas in mmHg is 691.6 mmHg