Sodium hydride reacts with excess water to produce aqueous sodium hydroxide and hydrogen gas: nah (s) h2o (l) → naoh (aq) h2 (g)a sample of nah weighing g will produce 982 ml of gas at 28.0 °c and 765 torr, when the hydrogen is collected over water. the vapor pressure of water at this temperature is 28 torr.

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.