In the following reaction, how many liters of oxygen will react with 270 liters of ethene (c2h4) at stp? c2h4(g) + 3o2(g) 2co2(g) + 2h2o(g) the volume of one mole of gas at stp is 22.4 liters

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? /

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?

May someone me with these science questions