4) Some seawater is evaporated. The sea salt obtained is found to be 86% sodium chond. How much sodium chloride
could be obtained from 200 g of this salt?
5 ) 5.0 g sample of dry ice (solid carbon dioxide) turned into
2400 cm³ of carbon dioxide gas at rtp. What was the
percentage purity of the dry ice? (Mr of co², =44)​

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)