What is the change in enthalpy for the following reaction? 2h2o2(aq) 2h2o(l) + o2(g) given: h2o: ∆h= -242 kj h2o2: ∆h= -609 kj a) -286 kj b) -572 kj c) 572 kj d) 286 kj

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

If you have 5.25 grams of methane (ch4), how many grams of co2 will you produce ?