Question

All the following solutions are prepared using either KNO3 (a solid, MW=101.10 g/mol, density = 2.11 g/ml) or Ethanol (a liquid, density = 0.79 g/ml).

PERCENTAGES:

1. Prepare 150 ml OF 67% KNO3, w/v = ___________g/150 ml water

   CALCULATIONS:

2. Prepare 900 ml of 30% KNO3, v/v = ___________mL/900 mL total CALCULATIONS:

   _________ g of KNO3 + __________ ml of water = 900 ml total

3. Prepare 300 ml of 45% ethanol solution, w/v = _____________ g/300 mL total CALCULATIONS:

   ___________ ml of ethanol plus _____________ ml water = 300 ml

4. Prepare 650 ml of 65% ethanol solution, w/v = ______________ g/650 ml total CALCULATIONS:

   __________ ml of ethanol plus ___________ ml water = 650 ml

5. Prepare 450 ml of 45 % ethanol solution, v/v = _____________ ml/450 ml total CALCULATIONS: *Hint: Using 100% ethanol, how much would you transfer for 45%

   ethanol in 450 ml total solution?

6. Prepare 450 ml of 45 % ethanol solution, w/v = _____________ g/450 ml total CALCULATIONS:

   ________________ ml ethanol + _______________ ml H2O = 450 ml

MOLARITY:

1. Prepare 800 ml of 0.65 M (molar, moles/L) KNO3 solution.

   CALCULATIONS:

   ___________g/800 ml

2. Based on the above solution of 0.65 M, how many:

   ________milli moles (mmol) /ml (10-3)

   ________micro moles (umol) /ul (10-6)

3. How many moles are in 85 ul of a 0.65 M solution? _____________ CALCULATIONS:

DILUTIONS:
How much of 78% KNO3 is required to make 450 ml of 23%. (c1v1=c2v2) CALCULATIONS:

_____________ml of 78% solution plus ___________ml H2O

Answer 1