Question

Vreau raspunsuri concrete!!!!
200g solutie NaOH de concentratie 20%
300 g solutie acid clorhidric de concentratie 10%.
A:Scrieti ecuatia reactiei si calculati care dintre reactanti se afla in exces si cu cat.
B:Ce culoare capata turnesolul adaugat in solutia finala?

Answer 1

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