Question

please answer all questions

8 Would ona be a good soap? a. True b. False 9 When one dissolves a solid in a pure liquid the new freeze point temperature of the liquid will... a. always need to taste testb. be raised c. stay the same d. be lowered 10 Similar to our Gravimetric Analysis lab, the experimenter, from Colorado. extracted 0.70g of gold from the ore. However, from his calculations he should have extracted 1.78g of gold. What is his % error? a. He's from Colorado so 0% b. 64.8% c. 39.3% d. 60.7%

Answer 1

Q: 8                 False

Soaps are water-soluble sodium or potassium salts of fatty acids. Medium-chain fatty acids are fatty acids with aliphatic tails of 6 to 12 carbons, which can form medium-chain triglycerides. Long-chain fatty acids are fatty acids with aliphatic tails of 13 to 21 carbons. Sodium or potassium salt of Long-chain fatty acids are used for soap preparation. Sodium salt of propanoic acid is very small in size, hence cannot used for prepare a good soap.

Q: 9                 d. be lowered

A solution will have a lower freezing point than a pure solvent. The freezing point is the temperature at which the liquid changes to a solid. At a given temperature, if a substance is added to a solvent (such as sugar dissolved in water), the solute-solvent interactions prevent the solvent from going into the solid phase. Hence freezing point will be lowered.

Q: 10               d. 60.7%

Percentage of error can be calculated by using the following equation

% of Error = (Approximate Value - Exact Value) Exact Value

For this problem, Approximate Value = 0.70 g

                                    Exact Value = 1.78 g