m NaCl = x
m p-pa NaCl 10% = x/0.3 + 300
x / (x/0.3+300) = 0.1
x= 0.1x/0.3 +30
0.3x - 0.1 x = 9
x = 45 г
mp-pa NaCl 30 % = 45/0.3 = 150 г
m NaCl = x
m p-pa NaCl 10% = x/0.3 + 300
x / (x/0.3+300) = 0.1
x= 0.1x/0.3 +30
0.3x - 0.1 x = 9
x = 45 г
mp-pa NaCl 30 % = 45/0.3 = 150 г