[derek0o0]

The level of chloride in calcium acetate was estimated by dissolving a sample in 15 ml water and adding 1ml 2M HNO3 and 1 ml AgNO3 which produced no more opalescence than 10 ml 5 ppm chloride standard solution and 5 ml water when treated with the same reagents.

The weight of sample required in the test to ensure that the maximum level of chloride in calcium acetate does not exceed 200 ppm is __________ mg. (3 sig. fig.)

I have no idea on this...could anyone give me some hint?
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