Predict the effect of increasing the container volume on the amounts of each reactant and product in the following reactions: (a) CH3OH(l) <--> CH3OH(g) (b) CH4(g) + NH3(g) <--> HCN(g) + 3H2(g)

a) The reaction will shift to the right

b) The reaction will shift to the right

Explanation:

In the first case, we have on the left side we have a liquid state in the right side we have gas state, therefore the change in the volume will affect the gas state, if we increase the volume the pressure will decrease, so if we have less pressure. So,  we can have more compounds in the gas state. Thus, the first reaction would increase the amount of product.

In the second reaction, we have gas states in all the compounds. So, a decrease in pressure (or increase in volume) causes the system to evolve in the direction in which there are more moles, that is, where the number of gaseous moles is greater. In this case we have 2 moles in total in the left side (1 mol of and 1 mol of ) and in the right side we will have 4 moles (1 mol of and 3 mol of ). Therefore, the reaction will move to the right side.

icc, international association for cereal chemistry

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.