Question

The maximum amounts of lead and copper allowed in drinking water are 0.015 mg/kg for lead and 1.3 mg/kg for copper. Tell the maximum amount of copper (in grams) allowed in 100 g of water.

Answer 1

Answer:

• The maximum amount of copper allowed in 100 g of water is 0.00013 g

Explanation:

To find the maximum amount of copper (in grams) allowed in 100 g of water use the maximum amount ratio (1.3 mg / kg)  and set a proportion with the unknown amount of copper (x) and the amount of water (100 g):

First, convert 100 g of water to kg: 100 g × 1 kg / 1000 g = 0.1 kg.

Now, set the proportion:

• 1.3 mg Cu / 1 Kg H₂O = x / 0.1 kg H₂O

Solve for x:

• x = 0.1 kg H₂O × 1.3 mg Cu / 1 kg H₂O = 0.13 mg Cu

Convert mg to grams:

• 0.13 mg × 1 g / 1,000 mg = 0.00013 g

Answer: 0.00013 g of copper.