Copper metal can reduce silver ions to metallic silver. The copper is oxidized to cupric ions. A copper strip with a mass of 2.00 grams is dipped into a solution of AgNO3. After some time has elapsed, the copper strip is coated with silver. The strip is removed from the solution, dried and weighed. The coated strip has a mass of 4.18 grams. What are the masses of copper and silver metals in the strip? (AM Cu=63.55; AW Ag=107.9)
Copper 0.95g Silver 3.23g Cu + 2AgNO3 ---> Cu(NO3)2 + 2Ag 63.55g + 339.82g ---> 187.57g + 215.8g divide all by 63.55 1 + 5.35 ---> 2.95 + 3.40 so, 1g Cu makes 3.40g Ag we started with 2g, let's say one gram was used. 1g left of Cu + 3.40g Ag = 4.4 grams in total we're looking for 4.18... 4.4 - 4.18 = 0.22 off knowing that 1g Cu makes 3.4 Ag, lets try to find how much copper and silver we will need to make the difference of .22g 1g Cu makes 3.40g Ag 4.40g total dividing by 2 0.5g Cu makes 1.70g Ag 2.20g total because the amount of silver is dependent on the amount of copper is used in this react we ill make the 0.5g of copper to 0.05g to make the 0.22 total we need. That is, 0.05g Cu makes 0.17g Ag 0.22g total At last: 1 - 0.05 = 0.95g Cu 3.4 - .17 = 3.23g Ag making 0.95 + 3.23 = 4.18 total I'm sorry if this is all a bit messy or even not the way you were shown.
