A student was working in a chemistry laboratory. He found that a bottle contained a white powdery substance but half of the label on the bottle was torn. The part of label still sticking to the bottle had NaH written on it. The student took this powdery substance in a test-tube and added dil. HCl to it. A gas was evolved which extinguished a burning match-stick.(a) Name the gas evolved.(b) Write the formula of white powdery substance.

A student was working in a chemistry laboratory. He found that a bottl

1.	A student was working in a chemistry laboratory. He found that a bottle contained a white powdery substance but half of the label on the bottle was torn. The part of label still sticking to the bottle had NaH written on it. The student took this powdery substance in a test-tube and added dil. HCl to it. A gas was evolved which extinguished a burning match-stick.(a) Name the gas evolved.(b) Write the formula of white powdery substance.
Answer» A student was working in a chemistry laboratory. He found that a bottle contained a white powdery substance but half of the label on the bottle was torn. The part of label still sticking to the bottle had NaH written on it. The student took this powdery substance in a test-tube and added dil. HCl to it. A gas was evolved which extinguished a burning match-stick. (a) Name the gas evolved. (b) Write the formula of white powdery substance.