Answer:
30.33L
Explanation:
Using Boyle's law which states that the volume of a given mass of gas is inversely proportional to the pressure, provided temperature remains constant and Charles law states that the volume of a given mass of gas is directly proportional to the temperature provided the pressure remains constant
P1V1/T1 = P2V2/ T2
P1 = 78atm, V1 = 21L , T1 = 900K
P2 = 45atm, V2 = ? , T2 =750K
78× 21 / 900 = 45×V2 / 750
1638/900 = 45 V2 / 750
1638×750 = 900×45V2
1228500 = 40500V2
Divide both sides by 40500
1228500÷40500= V2
V2 = 30.33L
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