Name two metals which react violently with cold water. Write any three observations you would make when such a metal is dropped into water. How would you identify the gas evolved, if any, during the reaction?
Sodium, Potassium When these metals are dropped in water, bubbles will be evolved due to evolution of hydrogen gas. The gas will catch fire and the solution will be alkaline, i.e., it will turn red litmus blue. Test: When a burning matchstick is brought near the gas, it burns explosively with a ‘pop’ sound and the splinter is extinguished.
