Answer
The mass of hydrogen that was produced during the reaction is 0.86 g.
Work Step by Step
1- Step one: Apply the law of conservation of mass for this chemical reaction:
m (of sodium metal) + m (of water) = m (of hydrogen gas) + m (of sodium hydroxide)
2- Step two: Replace the mass of sodium metal, mass of water and mass of sodium hydroxide:
19.7 g + 126.22 g = m (of hydrogen gas) + 145.06 g
3- Step three: find the mass of hydrogen that was produced in this chemical reaction
145.92 g = m (of hydrogen gas) + 145.06 g
145.92 g – 145.06 g = m (of hydrogen gas)
m (of hydrogen gas) = 0.86 g
