Răspunsuri

2014-04-12T13:40:51+03:00
HCl + Na ---> NaCl + 1/2 H2
c%=md/ms100=>md=c*ms/100= 50*20/100=10 g Na
36,5 g HCl.......23 g Na
x g HCl............10 g Na            x = 15,86957 g HCl =>nr moli =m/μ= 0,43478 moli
cM=nr moli/V=>V=0,43478/0,1=>V = 4,3478 litri HCl 
1 5 1
2014-04-12T20:07:43+03:00
0,1%.........................................50g solutie
20%............................................x
x=0,1*20/50=25g