Question

2 Probleme
1 Reactioneaza 200g H2SO4 de c=50% cu Zn . calculati masasi nr de moli de H2 degajati. 2 cu o cantitate de 50g solutie de acid clorhdric 10% sa neutralizat o solutie 50% . care este cantitatea de solutie NaOH folosita ?

Answer 1

1. C=md/ms*100=>md=50*200/100=100g H2SO4

MH2SO4=98g/mol

MH2=2g/mol

H2SO4 + Zn => ZnSO4 + H2

98g H2SO4........................2g H2
100g H2SO4......................xg H2

x=2*100/98=

98g H2SO4.........................1 mol H2
100g H2SO4......................x moli H2

x=100/98=

2. C=md/ms*100=>md=C*ms/100=10*50/100=5g HCl

MHCl=36,5g/mol

MNaOH=40g/mol

HCl + NaOH => NaCl + H2O

36,5g HCl...................40g NaOH
5g HCl........................xg NaOH

x=40*5/36,5=5,47945g NaOH (md)

C=md/ms*100=>ms=md*100/C=5,47945*100/50 =