Question

Maximum permitted level of lead in drinking water is 7.0 ppm. Based on

this information, how much lead can safely be dissolved in 1000 kg of water?

Answer 1

7 grams of lead

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First let's recall the ppm, it is same as 'parts per million'.

Also consider conversion of units:

• 1 kg = 1000 g
• 1 g = 1000 mg

We are given that maximum permitted level of lead in the drinking water is 7 ppm.

It means each kg of water can have:

• 1 kg * 7 ppm =
• 1 kg * 7 * 0.000001 =
• 1000 g * 0.000007 =
• 1000000 mg * 0.000007 =
• 7 mg of lead

1000 kg of water can have:

• 1000 * 7 =
• 7000 mg =
• 7 g of lead dissolved