Question

3 g clorat de potasiu cu 10% impuritati se descompun catalic, in proportie de 80%.
a) Cati moli de gaz se degaja?
b) Ce masa de clorura de potasiu se formeaza?
c) Calculati compozitia procentuala masica a amestecului solid final, daca impuritatile nu sunt volatile.

VA ROG DAU COROANA

Answer 1

M,KClO3= 122,5g/mol
M,KCl= 74,5g/mol
p= 90%

-calculez masa de sare pura
p=mpx100/mi---> 90=m,px100/3----> m,p= 2,7g   si  m,i= 3-2,7=>0,3g

-calculez masa de sare care se transforma
m= 80/100m,pur= 2,16g 

- deduc masa de clorura si moli gaz, din ecuatia
1mol..............................1mol......1,5mol
KClO3-------------------> KCl   +   3/2O2↑
122,5g............................74,5g...........1,5mol
2,16g...........................x........................y
x=1,3gKCl
y=0,0264molO2

TOTAL MASA SOLIDA= m,KCl+m,i= 1,3+0,3g=> 1,6g

1,6g amestec......1,3g KCl........0,3g impuritati
100g......................x........................y...........................calculeaza !!!!