[سحر البيان]

Number of moles = 0.8 x 2.5x60x60/96500x2

=0.0373 moles

mass = 0.0373 x 112.4 = 4.19 =4.2 g

C = moles x 96500 x n

c= 0.2 x 96500x3 = 57900 c

الاجابة D