Question

What is the mass of silver that can be prepared from 2.10 g of copper metal? Cu(s)+2AgNO3(aq)→Cu(NO3)2(aq)+2Ag(s)

Answer 1

Moles of Cu = 2.10 /21 = 0.1 Moles of Ag produced is 0.2 Mass of Ag = 0.2 x 108 = 21.6 g. 0.500 g/108 = 0.046 moles, but Cu. moles produced will be half as much, from equation = 0.23moles mass of Cu = 0.023 x2.10 = 0.0483g

Answer 2

 The mass  of silver that can be prepared from 2.10 g of copper  metal are  7.128  grams  of Ag

 calculation

 Cu(s)  + 2AgNO3 (aq)  →  Cu(NO3)2  +2 Ag (s)

  find the moles of Cu

 = mass/ molar mass

= 2.10 g / 63.5 g/mol = 0.033  moles

Use the mole  ratio to determine  the  moles of Ag

The mole ratio of Cu : Ag is  1:2 therefore the moles of Ag = 0.033 x2=0.066 moles

mass of Ag =  moles x molar  mass

= 0.066 moles x  108   g/mol  = 7.128   grams of Ag