If enough H2O is reacted to produce 3.40 moles of H2, then how may moles of O2 must have been made?

What is impossible to do with a hypothesis

Can someone me with questions 15 to 17 plz.

Which statement is true about hcl? (5 points) select one: a. it is a salt because it increases the concentration of metallic ions. b. it is a salt because it is formed by the reaction of an acid and a base. c. it is an acid because it increases the concentration of hydroxyl ions. d. it is an acid because it increases the concentration of hydronium ions.