Changes in pressure have a measurable effect: (select all that apply) Select all that apply:

in any system only in systems in which gases are involved
when there are equal numbers of moles of gas on the reactant and product sides of the equilibrium only
when the chemical reaction produces a change in the total number of gas molecules in the system

1. only in systems in which gases are involved

2. only when the chemical reaction produces a change in the total number of gas molecules in the system

Explanation:

According to Le Chatelier's principle, pressure will only affect a system in equilibrium containing gaseous reactants and products. However, change in the pressure will only affect the gaseous system in which the total number of moles of the reactants are different from the total number of moles of the products.

d

explanation: