A copper plate weighing 20 g was immersed in 20% silver nitrate with a volume of 220 ml (density = 1.2 g / ml).

A copper plate weighing 20 g was immersed in 20% silver nitrate with a volume of 220 ml (density = 1.2 g / ml). When the mass fractions of salts in the solution became equal, the plate was pulled out, washed and dried. determine the mass of the plate after the reaction

m (AgNO3) = (220 * 1.2) * 0.2 = 52.8; n (AgNO3) = 52.8: 170 = 0.3; n (Ag) = 0.3; n (Cu) = 0.3 / 2 = 0.15;

m (Ag) = 0.3 * 108 = 32.4;

2 AgNO3 + Cu = Cu (NO3) 2 + 2Ag m (Cu) = 0.15 * 64 = 9.6;

m (plates) = 20- (0.15 * 64) + (0.3 * 108) = 42.8g.