Calculate the initial molarity of MCHM in the river, assuming that the first part of the river is 7.60 feet deep, 100.0 yards wide, and 100.0 yards long. 1 gallon = 3.785 L.

[MCHM] = 7.52 M

Explanation:

This all about unit conversion

1 feet = 0.3048 meters

1 yard = 0.9144 meters

7.60 feet. 0.3048 = 2.31 meters deep

100 yd. 0.9144 meters = 91.44 meters long and 91.44 meters wide

In the river we have a volume of:

2.31 m. 91.44m. 91.44m = 19314.5 m³

1 dm³ = 1 L

1 dm³ = 0.001 m³

19314.5 m³ / 0.001 m³ = 19314542 L (The final volume of the river)

3.785 L = 1 gallon

In 19314542 L, we have (19314542 / 3.785) = 5102917 gallons

1 gallon = 128 oz

5102917 gallons. 128 = 653173376 oz

1 oz = 28.3495 g

653173376 oz. 28.495 = 1.86x10¹⁰ grams

Molar mass MCHM = 128 g/m

Moles of MCHM = 1.86x10¹⁰ grams / 128 g/m = 145312500 moles

Molarity = mol / L → 145312500 moles / 19314542 L = 7.52 M