List two observations which you make when you add a pinch of sodium hydrogen carbonate to acetic acid in a test tube. Write the chemical equation for the reaction that occurs. 

While studying combination reaction, on adding water to quicklime, name the product formed and write its colour. 

While studying decomposition reaction by heating ferrous sulphate crystals in a test-tube, a product is formed in the test-tube. Name the product and write its colour.