le lucram pe toate
2 t calcar / 80% puritate
2 t calcar impur (m.imp.) ...................... 100%
x t calcar pur (m.pura) .......................... (p%) 80%
= 2x80/100 = 1,6 t calcar pur
sau
p% = m.px100/m.imp
=> m.p = m.imp.xp%/100
= 2x80/100 = 1,6 t calcar pur = 1600 kg = 16x10la5 g
nr.moli = m.pura/M, M.CaCO3 = 40+12+16x3 = 100 g/mol
=> nr.moli = 16x10la5 g / 100 = 16x10la3 moli CaCO3
m.impuritati = m.impura - m.pura
= 2 - 1,6 = 0,4 t = 400 kg impuritati
468 kg sare gema / 85% puritate
468 kg sare gema (m.imp.) ...................... 100%
x kg sare gema pura (m.pura) ................. (p%) 85%
= 468x85/100 = 397,8 kg
sau
p% = m.px100/m.imp
=> m.p = m.imp.xp%/100
= 468x85/100 = 397,8 kg = 397800 g sare pura
nr.moli = m.pura/M, M.NaCl = 23+35,5 = 58,5 g/mol
=> nr.moli = 397800 g / 58,5 = 680 moli NaCl
m.impuritati = m.impura - m.pura
= 468 - 397,8 = 70,2 kg impuritati
800 kg pirita (FeS2) / 60%
800 kg pirita impura (m.imp.) ...................... 100%
x kg pirita pura (m.pura) .......................... (p%) 60%
= 800x60/100 = 480 kg pirita pura
sau
p% = m.px100/m.imp
=> m.p = m.imp.xp%/100
= 800x60/100 = 480 kg = 480000 g pirita
nr.moli = m.pura/M, M.FeS2 = 56+32x2 = 120 g/mol
=> nr.moli = 480000 g / 120 = 4000 moli FeS2
m.impuritati = m.impura - m.pura
= 800 - 480 = 320 kg impuritati
soda caustica / 90%
se considera 100 kg soda caustica impura
100 kg soda impura (m.imp.) ...................... 100%
x kg soda pura (m.pura) .......................... (p%) 90%
= 100x90/100 = 90 kg soda pura
sau
p% = m.px100/m.imp
=> m.p = m.imp.xp%/100
= 100x90/100 = 90 kg = 90000 g soda
nr.moli = m.pura/M, M.NaOH = 23+1+16 = 40 g/mol
=> nr.moli = 90000 g / 40 = 2250 moli NaOH
m.impuritati = m.impura - m.pura
= 100 - 90 = 10 kg impuritati
