Which arrangement of electrons is correct? Help please its timed!!!

Used the balanced equation 2h2+ o2 - -> 2h2o. if you have 7.2 grams of o2 , how many grams of h2o can you produce ?

If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution

An excess of lithium oxide undergoes a synthesis reaction with water to produce lithium hydroxide li2o+h2o→2lioh if 1.05 g of water reacted, what is the theoretical yield of lithium hydroxide? a) 5.83 x 10–2 g lioh b) 1.17 x 10–1 g lioh c) 2.79 x 100 g lioh d) 1.40 x 100 g lioh