Describe how you would prepare a 1000mL solution of 0.25 sodium hydroxide using the 8M stock solution

As a part of an experiment a student burns propane to produce carbon dioxide and water she remembers that she must follow the law conservation of matter when writing a balanced chemical equation which of these equation adheres to the law of conservation of matter

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.