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.

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:

Solve for x:

Convert mg to grams:

0.00013 g of copper.

Potassium carbonate is soluble in water, while calcium carbonate is insoluble. Weigh a sample of the unknown mixture accurately and stir the sample with water. Filter the suspension and find out the mass of the residue collected. It gives the amount of insoluble calcium carbonate present in the mixture.

Explanation: