Some of you know this, I could use your help very well

(a) calculate the molarity of a solution that contains 0.0345 mol nh4cl in 400 ml of solution. (b) how many moles of hno3 are present in 35.0 ml of a 2.20 m solution of nitric acid? (c) how many milliliters of 1.50 m koh solution are needed to supply 0.125 mil of koh ?

Someone me i need with this stuff

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.