Which statement best describes a mole?
it is used mainly for writing chemical formulas.
it is used for chemical equations that have reversible reactions.
it is used for directly comparing the amounts of substances.
it is used mainly for dealing with fluid substances.

Describe the interaction that occurs between two objects with the same electrical charge.

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

Choose an equation that represents an enzyme-catalyzed reaction. (a) enzyme + substrate → enzyme-substrate complex (b) enzyme + substrate ←−→ enzyme + products (c) enzyme + substrate ←−→ enzyme-substrate complex → enzyme + products (d) enzyme + substrate ←−→ enzyme-substrate complex → enzyme-substrate complex + products