B. The surface of a silver cup turns black when it is exposed to air.
Answer:
Subtract the mass of the CuSO4⋅ 5H2O from the mass of CuSO4 is the right one
I believe the correct answer from the choices listed above is the third option. The <span>oxidation number of Nitrogen in HNO2 would be +3. It is calculated as follows:
1 + x + (-2)(2) = 0
x = +3
Hope this answers the question. Have a nice day.</span>
The completed and balanced equation is:
<span>Hg(N<span>O3</span><span>)2</span>+N<span>a2</span>Cr<span>O4</span>=HgCr<span>O4</span>+2Na(N<span>O3</span>)
Hope this helps :)</span>