Question

Calibration Method 1: Regular Calibration

Starting with solid CaCO₃, describe how you will prepare Ca²⁺ standards in 0.1 M nitric acid in the concentration range 5-60 ppm (MW CaCO₃ = 100.08 and MW Ca = 40.08).

Remember you do not want to weigh out very small amounts because small fluctuations in the balance can create large errors. You should not weigh out an amount of CaCO₃ less than 0.1 g. Therefore, you may need to prepare a stock solution with a higher concentration than the desired range (such as 150 ppm) and then dilute the stock solution to make standards in the appropriate range.

Include the mass of the CaCO₃, the steps for preparing the solution, and the types of pipets and volumetric glassware you will use.