My last chem class question for dimensional analyst ?

Question

the density of the water is 1.0 g/ml. what is the density of water in pounds/gallon? (1quart = 9.46 x 10^-1 L; 1 g = 2.20 x 10^-3 lb)

Answer 1

8.333 Pounds per Gallon

Answer 2

Do it step by step

1 g/mL (1000 mL/L) = 1000 g/L

1000 g/L (0.946 L/quart) (4 quarts/gallon) = 3784 g/gallon

now the top

3784 g/gallon (0.0022 lb/g) = 8.33 lbs/gallon

If you do it step by step, you never go wrong.