help please with clear solutions

7) A good disinfectant commonly used in the lab is 2% glutaraldehyde, made up weekly to fill 6250m 1. wash bottles. Your stock solution is 25% glutaraldehyde, which is diluted with tap water. How would you prepare enough 2% to fill all 6 wash bottles? 8) In the lab a procedure calls for 200ml of a 2% solution of red cells. A 50% solution is available. How much of the 50% solution is needed? 9) A 1% solution of hydrochloric acid is required for a procedure. A 5% solution is available. How much of the 5% solution will be required to make 500ml of a 1% solution? 10) One liter of 70% alcohol is needed. How much 95% alcohol is required? 11) One hundred ml of 2% acetic acid are needed. How many ml of 5% acetic acid are required to make 100ml of a 2% solution? 12) In a lab, 400ml of a 3% solution is required. Only a 5% solution is available. How much of the 5% solution is needed, and how is the 3% solution prepared