Apiece of sodium metal undergoes complete reaction
withwater.
a. write the complete balanced equation governing
thisreaction.
b. the hydrogen gas generated is collected over water
at25.0*c. the volume of the gas is 246 ml measured at 101.3kpa.
calculate the number of grams of sodium used in thereaction.

(a) Equation of reaction:

2Na + 2H20 = 2NaOH + H2

(b) 0.46g of sodium was used in the reaction

Explanation:

(a) 2 moles of sodium reacted with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas

(b) mass of hydrogen gas produced (m) = PVM/RT

P = 101.3kpa = 1atm, V = 246mL = 246cm^3, M = 2g/mol, R = 82.057cm^3.atm/gmol.K, T = 25°C = 25+273 = 298K

m = (1×246×2)/(82.057×298) = 0.02g of hydrogen gas

From the equation of reaction

2 moles (46g) of sodium produced 1 mole (2g) of hydrogen gas

0.02g of hydrogen gas was produced by (46×0.02)/2 = 0.46g of sodium