Home › WAEC WASSCE › Chemistry › Stoichiometry of Chemical Reactions › Copper wire is placed in silver nitrate solution…
Copper wire is placed in silver nitrate solution and the solution turns blue. What causes the blue colour?
ASilver ions still left in the solution
BNitrate ions released by the reaction
CSolid silver forming on the copper wire
DCopper(II) ions dissolving in the solution
Answer & Solution
Correct answer: D. Copper(II) ions dissolving in the solution
1. The equation is Cu(s) plus 2AgNO3(aq) giving Cu(NO3)2(aq) and 2Ag(s).
2. Silver ions gain electrons and deposit as grey silver metal on the wire.
3. Copper atoms lose electrons and enter solution as Cu2+ ions.
4. Dissolved copper ions are what give the solution its blue colour.
5. Nitrate ions are spectators here and are colourless in solution.
_Source: OpenStax Chemistry (CC BY 4.0), Ch 4 "Stoichiometry of Chemical Reactions", section 4.2 Classifying Chemical Reactions_
Related questions
In the reaction between sodium and chlorine, sodium is oxidised, which means chlorine:Ordering the three ways of writing a reaction from most to least detail about ions gives:When one element appears in more than one formula on the same side of an equation, you musWhen balancing a combustion equation, an odd number of oxygen atoms on the product side isCompounds that produce hydroxide ions by chemically reacting with water, rather than by diA double arrow is used in an acid equation to indicate that the acid is:A neutralisation reaction has an acid and a base as reactants and typically produces:Sodium hydroxide is classified as a strong base because in water it: