Grade 12 Chem - please check answer
posted by Laura on .
The four possible unknown chemicals are: Cu(s), Ca(OH)2(s), KNO3(aq) and C6H12O6(aq).
a) colorless solutions, high electrical conductivity, no change on litmus paper
b)white crystals, no electrical conductivity, red to blue on litmus
c) shiny brown wire, high electrical conductivity, no change on litmus
d) colorless solution, low electrical conductivity, no change on litmus
I don't know but I assume C6H12O6 is glucose. It is a colorless solution but it doesn't conduct electricity since it doesn't ionize. Therefore, glucose can't be the answer for a).
I suppose your answer is correct but if so it is a flawed question because Ca(OH)2(s)is a solid and will not turn litmus paper unless some water is added.
I think c probably is correct although I don't think of copper wire as being brown. It does have a brownish cast if slightly oxidized from air.
You answer of KNO3(aq) for d can't be correct for KNO3(aq) is a 100% ionized and conducts electricity very well.