Consider the combustion of glucose: c6h12o6(s) + 6 o2(g) ←→ 6 co2(g) + 6 h2o(g) ∆h = −2, 800 kj/mol which condition i) adding more carbon dioxide ii) performing the reaction in a hotter environment iii) decreasing the pressure of the system would result in the production of additional water vapor?

The answer is iii) decreasing the pressure of the system. When the pressure is decreased, the equilibrium will shift to the right because it has 12 moles of gas which is greater than the number of moles of gas on the left side, which is 6 moles. Equilibrium shifting to the side that exerts greater pressure is favored to offset the decrease in pressure.

Temperature and pressure

Yes it would be a physical change.