Answer:
The solution is 10^-2 or 0.01M in HCl.
Explanation:
meaning of pH is "power of hydrogen".
what is the molar concentration of a HCl solution with pH=2?
Let say pH=2
[H+]=10^-2M
HCL is a strong acid that dissociates completely:
[H+]=[HCL]
Therefore solution is 10^-2 or 0.01M in HCL.
Not 100% sure but I think 40 seconds
The copper wire was sanded before burning in order to make sure that copper metal was exposed on the surface of the wire.
Answer: B
Explanation
The copper wire when placed in atmosphere without coating leads to oxidation of copper metal with respect to the impurities present in the atmosphere.
As copper is electropositive in nature, so electronegative ions present in the universe will try to react with copper and the copper will react easily with other elements.
So generally copper wire is coated with color or polymer coating.
In this case, the copper wire without any coating is sanded, so that the eddy sheets or polishing materials on friction with copper wire will remove the impurities by the electrostatic law of conservation of charges and charge transfer.
As the impurities are removed when copper wire is sanded, the copper atoms will be exposed on the surface of the wire leading to burning of copper in the copper wire.