Can a chemical reaction occur even if one reactant is missing

1) in saturated limewater, [h+ ]=3.98x10-13 m. a) find [oh]-/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 2) in butter, [h+ ]=6.0x10-7 m. a) find [oh]-/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 3) in peaches, [oh]=3.16x10-11 m a) find [h+ ]/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 4) during the course of the day, human saliva varies between being acidic and basic. if [oh]=3.16x10-8 m, a) find [h+ ]/ b) what is the ph? / c) is the solution acidic, basic, or neutral? /

Non renewable resources like petroleum eventually

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system