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. Express these values in parts per million, and tell the maximum amount of each (in grams) allowed in 100 g of water.

Verified step by step guidance

1. Understand that parts per million (ppm) is a way to express very dilute concentrations of substances. 1 ppm is equivalent to 1 mg of substance per kg of solution.
2. Convert the given concentrations from mg/kg to ppm. Since 1 mg/kg is equivalent to 1 ppm, the concentration values for lead and copper in ppm are the same as their values in mg/kg.
3. Calculate the maximum amount of lead in grams allowed in 100 g of water. Use the concentration of lead in ppm and the mass of water to find the mass of lead.
4. Calculate the maximum amount of copper in grams allowed in 100 g of water. Use the concentration of copper in ppm and the mass of water to find the mass of copper.
5. Express the calculated masses of lead and copper in grams, ensuring the units are consistent with the problem's requirements.

Key Concepts

Parts Per Million (PPM)

Parts per million (PPM) is a unit of measurement used to describe the concentration of a substance in a solution. It indicates how many parts of a substance are present in one million parts of the total solution. For example, 1 PPM means 1 milligram of a substance in 1 liter of water, which is equivalent to 1 mg/kg.

Conversion from mg/kg to PPM

Since 1 mg/kg is equivalent to 1 PPM, converting the maximum allowable concentrations of lead and copper from mg/kg to PPM is straightforward. This means that the values given (0.015 mg/kg for lead and 1.3 mg/kg for copper) can be directly interpreted as 0.015 PPM and 1.3 PPM, respectively.

Calculating Maximum Amounts in Grams

To find the maximum amount of a substance allowed in a specific weight of water, you can use the concentration in PPM. For example, to calculate the maximum grams of lead in 100 g of water at 0.015 PPM, you multiply 100 g by 0.015 PPM (or 0.015 mg/g), resulting in 0.0015 g. This method applies similarly for copper.