Question

3.(2p) Ce cantitate de apa contine 10 grame de hidrogen? Daca peste cantitatea de apa ce contine
10 g hidrogen se adauga 5 moli H,SO, calculati concentratia procentuala a solutiei obtinute

Answer 1

M.H2O = 2*1+16 = 18 g/mol

18g .................. 2g H

m g ................... 10g H

= 90 g apa

H2SO4 = 2*1+32+4*16 = 98 g/mol

nr.moli = m/M => m = nr.moli*M

= 5*98 = 490 g (md)

ms = md+m.apa = 490+90 = 580 g sol.

c% = md*100/ms = 490*100/580 = 84,50%