1.
ms = 168 g
c% = 10%, c = mdx100/ms
=> md = msxc/100
=> md = 168x10/100 = 16,8 g KOH
16,8................................. a g
2KOH + H2SO4 => K2SO4 + 2H20
2x56............................. 174
=> a = 16,8x174/2x56 = 26,1 g KOH
2.
234 g......................................... ........ Ct
2NaCl + H2SO4 => Na2SO4 + 2HCl
2x58,5............................... ............2x36,4
=> Ct = 234x2x36,5/2x58,5 = 146 g
randamentul n = Cpx100/ Ct
= n = 109,5x100/146 = 75%