Prepare 100mL of a 3%m/v NaCl solution.      i) What is the total volume of solution wanted?      ii) What is the mass of NaCl (solute) needed?      iii) What is the volume of water (solvent) needed?

How many mL of 10 x stock solution would you need to make 118 mL of 1x PBS?  Report your answer to 1 decimal place.

3. a) An aqueous solution is 3.50% by mass potassium bromide, KBr, and has a density of 1.02 g/mL. The molality of potassium bromide in the solution is _________m. b)An aqueous solution of magnesium nitrate has a concentration of 0.474 molal. The percent by mass of magnesium nitrate in the solution is _________%. c)An aqueous solution of cobalt(II) bromide has a concentration of 0.153 molal. The percent by mass of cobalt(II) bromide in the solution is _________%.

Prepare 5 liters of a 0.2 M dextrose solution using 5 liters of 5 M dextrose.

2. 3. Perform all the calculations necessary for the volume of stock solution or water, in mL, needed to make the dilute solutions listed below. a. b. C. Make: 200 mL of 30% Ethanol dilute solution Stock Volume needed (mL) 95% Ethanol Reagent water Make: 100mL of .09%NaCL Stock 1% NaCl Reagent water 30% SDS 3 M NaOH Make: 100 mL of a 3% SDS and 0.5 MNaOH dilute solution as follows: Stock Volume needed (mL) Reagent water 200 mL Total 1% Lactose 1% Dextrose Volume needed (mL) 100 mL Total Calculate the grams of chemical needed for each stock listed below. Concentration of Stock to Prepare Volume of Stock Needed 1% Sucrose 100 mL Total 10 mL 20 mL 25 mL Amount of chemical Needed (in grams) Your instructor will have you make ONE of the above solutions-ask your instructor which solution to make.