Nitrogen and oxygen are in unpolluted air
It would repel some of the negatively charged electrons of the wall so the answer would be C. The wall and the ballon repel each other
Pure substances are substances which are homogenous in nature. They either consists of atoms of 1 kind or molecules of 1 kind. Atoms are seen in elements, where as molecules are seen in compounds like Acids, Bases, etc.
They mostly have fixed properties like boiling and melting points and are uniform in nature. :D
A reaction in which Oxygen (O₂) is produced from Mercury Oxide (HgO) would be a decomposition reaction.
2HgO → 2Hg + O₂
If 250g of O₂ is needed to be produced,
then the moles of oxygen needed to be produced = 250g ÷ 32 g/mol
= 7.8125 mol
Now, the mole ratio of Oxygen to Mercury Oxide is 1 : 2
∴ if the moles of oxygen = 7.8125 mol
then the moles of mercury oxide = 7.8125 mol × 2
= 15.625 mol
Thus the number moles of HgO needed to produce 250.0 g of O₂ is 15.625 mol