Question

Cata apa trebuie adaugata la 500g solutie de soda , de concentratie 5% ptr a o dilua 2%

Vaa rogg cat mai repedeee posiblll !! plizz

Answer 1

100 g sol ..................5 g soda

500 g sol......................5x5=25 g soda si 475 g apa

100g sol finala ....................2 g soda
 xg sol finala................25 g soda

x=2500/2=1225 g solutie  din care      25 g sunt soda   si 1200 sunt apa 

1200 ml apa finala-475g apa initial =725 g apa ce trebuie adaugata