The OH- concentration in a 2.5 x 10-3 M Ba(OH)2 solution is A) 1.2 x 10^-2 M.
B) 2.5 x 10^-3 M.
C) 5.0 x 10^-3 M.
D) 4.0 x 10^-12 M.

How do you know when a chemical reaction has occurred

The equation below shows a chemical reaction. a + b + heat —> c + d according to the law of conservation of energy, which statement is true? a. the reactants absorb heat because they have less energy than the products. b. the products release heat because they have more energy than the reactants. c. the reactants generate heat because they have more energy than the products. d. the products require heat to form because they have less energy than the reactants.

Two changes are described below. a green banana turns yellow and ripens. a layer of rust forms on an iron nail. which statement is true about the two changes? a) both are chemical changes because new substances are formed. b) both are physical changes because only the physical state of the substances change. c) a is a physical change due to a change of state, but b is a chemical change because new molecules are formed. d) a is a chemical change due to a change of state, but b is a physical change because new molecules are formed.