7.)The average salinity of sea water is A.3%B.3.5% C.2.5%D.2% View Answer Correct Answer: B. 8.)What are soaps? (A)Salts of silicates (B)Ester of heavy fatty acids (C)Sodium or potassium salts of heavier fatty acids (D)Mixture of glycerol and alcohol View Answer Correct Answer: C. 9.)Which of the following is a protein? (A)Wool(B)Starch (C)Cellulose(D)Natural rubber View Answer Correct Answer: D. 10.)Which of the following is commonly called a polyamide? (A)Rayon(B)Orion (C)Terylene(D)Nylon View Answer Correct Answer: D. 11.)The gas usually filled in the electric bulb is A.NitrogenB.Hydrogen C.Carbon dioxideD.Oxygen View Answer Correct Answer: A. 12.)Which of the gas is not known as green house gas? A.MethaneB.Nitrous oxide C.Carbon dioxideD.Hydrogen View Answer Correct Answer: D.