Question

va rog la chimie .....​

Answer 1

8/.

ZnSO4*7H2O

161       + 7x18 = 287 g/mol

287 g cristal.  ............ 161 g ZnSO4 anhidru

50 g ............................. a = 28,05 g sare anhidra

ms final = m.crsialohidrat + m.apa

= 50 + 150 = 200 g

md = 28,05 g

c% = 28,05x100/200 = 14% => b).

7/.

ms1 = 80 g , c1% = 20%

ms2 = 120 g , c2% = 30%

stim ca c% = mdx100/ms

avem ms.final = 80+120 = 200 g

md1 = ms1xc1/100 = 80x20/100 = 16 g

md2 = ms2xc2/100 = 120x30/100 = 36 g

=> md.final = 16+36 = 52 g

=> c.f.% = md.finalx100/ms.final

= 52x100/200 = 28%