4. Which of the followings when added to pure water decreases P"l a) NaCl b) NH4Cl 2) NaOH d) CH3COONa 5. When an organic compound is treated with KCN and then hydrolysed in acidic medium gives propanoic acid , the compound is a) CH3COCl b) CH3CH2Cl c) CH3I d) CH3CH2OH 6. When butan-2-ol is refluxed with thionyl chloride in the presence of pyridine and then boiled with alcoholic KOH, the major product is a) but-2-ene b) propene c) propane d) but-1-ene