Question

Date: 100 g HCl, concentratia=3,65%, 100 g NaOH, concentratia=44%. Se cere cantitatea in exces
Va rog e cu nota

Answer 1

Răspuns:

din definitia conc.procentuale,

100g HCl    contine  3,65gHCl,    adica m/miu=3,65/36,5mol=0,1molHCl

100g NaOH               44g NaOH            m/miu= 44/40mol=1.1 molNaOH

DIN ecuatia chimica  

1mol.......1mol

HCl + NaOH---> NaCL + H2O

0,1mol.....x

x=0,1molNaOH intrat in reactie

niu,NaOH in exces= 1,1-0,1=> 1mol

m,NaOH in exces= niuxmiu=1molx40g/mol= 40g

Explicație: