Question

Suppose that you have 70 grams of calcium chloride (CaCl2) contaminated with 5% sodium chloride (NaCl) and 2% sand. You dissolve the impure solid in 54 ml of hot water, and allow it to cool and crystallize. What would be the maximum mass (grams) of purified CaCl2 that would you would be able to recover

Answer 1

65.1 grams

Step-by-step explanation:

The percentage of impurities in the contaminated CaCl₂ sample is:

• % of NaCl + % of sand = 7%

Meaning that the purity of the sample is (100 - 7) 93%.

Now we calculate the mass of pure CaCl₂ in the contaminated sample:

• 70 g * 93/100 = 65.1 g

Thus the answer is 65.1 grams, as that amount is how much CaCl₂ is in the sample and it would be impossible to obtain more than that.