Question

CHEM 2A Class Pack F18 25. Suppose a sample of carbon dioxide gas at 2.50 atm is heated from 293K to 425K. What is the new pressure of the gas? 26. What will be the final pressure of a 735mL sample of a gas at 795mmHg after it is expanded to 1.00L at constant temperature? 27. What volume will 22.5mL of hydrogen gas collected over water at 755.5mmHg and 26°C occupy at STP? iant nress

Answer 1

ANSWER

Q25 CO2 gas at 2.50atm

i.e P1 = 2.50atm , T1 =293k and T2 = 425k

Relationship between temperature and pressure

P directly proportional to T

P/T = Constant

P1/T1 = P2/T2

P2 = P1.T2/T1= 2.50×425/293 = 3.62

$P2 = 3.62atm$

Q26 According to question Given that,

V1 = 735ml , P1= 795mmHg and V2 = 1L = 1000ml

And P2 = ?

According to Boyle's low, P inversely to Volume

P1 V1 = P2 V2

P2 = P1.V1/V2 = 795×735/1000 = 584.32mmHg

$P2 = 584.32mmHg$.

Q27 According to question Given that,

V1 = 22.5ml , P1 =755.5mmHg and T1 =26°C=299k

And at STP, T2 = 273k and P2 = 760mmHg

According to Combined gas low,

$P1V1/T1 =P2V2/T2$

V2 = P1.V1.T2/T1.P2 = 755.5×22.5×273/299×760=20.42

$V2 =20.42ml$