A mixture of 5 gases exerts a pressure of 101.8 kPa. The pressure exerted by hydrogen gas is 40.8 kPa, by bromine gas is 26.7 kPa, by Fluorine gas is 3.5 kPa, and by helium gas is 12.7 kPa. What is the pressure exerted by the final gas?

The pressure exerted by the final gas is 18.1 kPa

Explanation:

We note that according to Dalton's law of partial pressure, the pressure a=exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture

The gases and their partial pressures are;

Hydrogen = 40.8 kPa

Bromine = 26.7 kPa

Fluorine = 3.5 kPa

Helium = 12.7 kPa

Final gas pressure = required

Therefore,

40.8 + 26.7 + 3.5 + 12.7 + Final gas pressure = 101.8 kPa

83.7 kPa + Final gas pressure = 101.8 kPa

Final gas pressure = 101.8 kPa - 83.7 kPa = 18.1 kPa

The pressure exerted by the final gas = 18.1 kPa.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.