Calc. nr.moli H2:, stiind ca 1mol gaz are vol. 22,4l
niu= 4,48l/22,4l/mol=0,2mol
2mol 1mol
2Na +2H2O -> 2NaOH + H2↑
niu-=0,4mol 0,2mol
Calc .masa : m=0,4molx23g/mol= 9,2g Na ; acesta e sodiu pur din 10g
Calc. pUritatea: p/100= m,pur /m impur; p=9,2x100/10= 92%