Relate the effect of temperature and pressure on
as to the model of a gas given by the kinetic-
molecular theory.

According to the Kinetic-molecular theory, increase in temperature causes the gas molecules' average speed and kinetic energy to increase.if the volume of the container is held constant, collision of gas molecules will be frequent and with more force on the walls of the container,making the pressure to increase.

Explanation:

Remember that a gas pressure is affected by the rapidness of moving gas molecules which is directly proportion to number of molecules hitting a unit area of the container in a unit time.Kinetic-molecular theory can be explained from Boyle's law where a decreased volume of a container compresses the gas in the container due to reduced area,making gas molecules to collide with high frequency rising the pressure exerted by the gas.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.