Question

Determinati masa de solutie Na OH 20% care reactioneaza cu 500 ml solutie H NO3 2 molari.

Answer 1

Vs = 500 ml = 0,5 L

Cm = 2 M, stim ca Cm = niu/Vs

=> niu = CmxVs = 2x0,5 = 1 moli HNO3

md g      1 mol

NaOH + HNO3 => NaNO3 + H2O

40          1

=> md = 40x1/1 = 40 g NaOH

stim ca c% = mdx100/ms

=> ms = mdx100/c%

= 40x100/20 = 200 g sol. NaOH