Mik hok bt đúng ko nha
n Na= 23/23= 1 mol
2Na + 2H2O -> 2NaOH + H2
2 : 2 : 2 : 1 (mol)
1 -> 1 -> 1 -> 0,5 (mol)
m H2= 0,5 x 2= 1(g)
m NaOH = 1 x 40 = 40g
m ddNaOH = m Na + m H2O - m H2
= 23 + 100 - 1 =122 g
C% dd NaOH = m NaOH/ m ddNaOH x 100% = 40/122 x 100%= 32,8 %