Question

Rezolvati problema la chimie. Urgent va rog!! P.s. am uitat sa pun chimie

Answer 1

Se da:

m sol (HCI)=50 g

w(HCI)=3.65%

m(NaHCO3)-?

Rezolvare:

1. Calculam m s.d.(HCI) conform formulei

w=lm s.d./m sol)*100%; m s.d.(HCI)=w*m sol/ 100%=3.65% * 50g / 100% = 1.825 g.

2. Scriem ecuatia reactiei si introducem datele

din problema:

xg

1.825g

NaHCO3 + HCI

=NaCl+H2O+CO2

1mol*91g/mol= | Imol*36.5g/mol=

=91 g

=35.5g

M(NaHCO3)=30+1+12+16*3=91 g/mol. M(HCI)=1+35.5=36.5 g/mol.

3. Calculam m(NaHCO3):

xg/91 g = 1.825 g/ 36.5 g;

xg = 91 g * 1.825 g/ 36.5 g;

xg= 4.55 g.

Raspuns: m(HCI)=4.55 g.

Sper ca e corect