Which list contains all pure substance

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

Which of the following best supports the concept that genetic information is passed on to offspring from both of their parents, not just one?

In the lab, ammonia was mixed with water to form ammonium hydroxide. what is/are the reactant(s)? o water and ammonia o ammonia o ammonium hydroxide need