A: C=md×100:ms=>
md=C×ms:100
mdNaOH=200×20:100=40g NaOH
MNaOH=ANa+AO+AH=23+16+1=40g/mol
VNaOH=m:M=40:40=1 mol
mdHCl=300×10:100=30g
MHCl=AH+ACl=1+35,5=36,5g/mol
VHCl=m:M=30:36,5=0,8 moli HCl
1 mol 1mol
NaOH+HCl=H2O+NaCl
1mol 0,8moli
=> NaOH este in exces:
1-0,8=0,2 moli in exces NaOH
B: culoarea roz-deschis