PTHH:2 NaOH + MgSO4 -> Mg(OH)2 + Na2SO4
Ta có: nMgSO4= (250/1000). 0,1= 0,025(mol)
=> nNaOH= nMgSO4= 0,025(mol)
=> CMddNaOH = 0,025: (20:1000)= 1,25 (M)
n MgSO4 = 0,025 (mol)
n Mg(OH)2 = 1,16/58 = 0,02 mol
2NaOH + MgSO4 -> Mg(OH)2 + Na2SO4
bd: ..............0,025.............0,02............................mol
p/ứ:..0,04....0,02..............0,02..............0,02
sau: 0,04....0,005..............0....................0,02
=> CMNaOH = 0,04/0,02 = 2 (M)