Jawabanmu

2014-02-23T20:30:39+07:00
H+=10^-12
OH- = 10^-2
OH- = M x n
10^-2 = M x 1
M = 10^-2
M = mol / vol => vol= 500 ml = 0,5 liter
10^-2 = (gram/mr) / vol
10^-2 = (x/40) / 0,5
x = 1/5 gram
x = 0,2 gram