Question

4,5 si 6 va rog mult e urgent

Answer 1

4.

50 t = 50000 kg sare gema

5000 kg sunt impuritati

m.pura = m.impura - m.impuritati

= 50000 - 5000 = 45000 kg

100% .................................... 50000 kg impuri

p% ...................................... 45000 kg puri

= 90%

sau

p% = m.purax100/m.impura

= 45000x100/50000 = 90%

5.

m.impura = 2750 kg zahar

p% = 90%

100% .............................. 2750 kg zahar impur

p=90% ........................... m = 2475 kg zahar pur

m.impuritati = m.impura - m.pura

= 2750 - 2475 = 275 kg impuritati

6.

100% impur - 90% pur = 10% impuritati

10% .................................... 0,03 g impuritati

100% .............................. m = 0,3 g masa impura supusa analizei

=> m.pura = m.impura - m.impuritati

= 0,3-0,03 = 0,27 g