What is the answer I need help I’m stuck

If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

Answer explain why it is not possible to deduce a complete order of reactivity.