Rezolvati urmatoarele probleme, urgent, dau coroana 1. În 400 grame soluţie se găsesc 80 grame zahăr. Ce concentraţie procentuală are soluţia?
2. În 500 Kg soluţie sunt dizolvate 75 Kg sodă de rufe. Ce concentraţie procentuală are soluţia ?
3. Ce cantitate de soluţie de concentraţie 15% se obţine prin dizolvarea a 60 Kg piatră vânătă în apă ?

22. a flask containing 450 ml of 0.50 m h2so4 was accidentally knocked to the floor. how many grams of nahco, do you need to put on the spill to neutralize the acid according to the following equation: h2so4(aq)+2 nahcos(aq) na,so(aq) +2 h20()+2 co2(g) d) 38 g a) 2.3 g b) 9.5 g c) 19 g

In 2002, the rare earth elements mine in mountain pass, california was closed because

When 13.3 g koh is dissolved in 102.7 g of water in a coffee-cup calorimeter, the temperature rises from 21.4 °c to 31.53 °c. what is the enthalpy change per gram of koh (j/g) dissolved in the water? * take the density of water as 1.00 g/ml. * assume that the solution has a specific heat capacity of 4.18 j/g*k. enter to 1 decimal place. do not forget the appropriate sign /(+). canvas may auto-delete the (+) sign