An exothermic reaction has occurred. You can remember that EXothermic means that energy is EXiting the system. If energy enters the system, it’s endothermic.
The formula for dimethyl mercury is. HgC2H6 = (2x12) + (6x1) + (1x200.6) = 230.6
So the molar mass of dimethyl mercury is 230.6 g/mol.
Number of moles in 4.2g of dimethymercury = 4.2/ 230.6 = 0.0182 moles.
1 moles of dimethymercury contains 6.02 * 10^23
Hence 0.0182 moles contains X
X = 0.0182 * 6.02 * 10^23 = 0.10952 * 10^23 = 1.0952 * 10^22.
Combustion reaction because it produces water and carbon dioxide
I think it will be D or B but my mine answer is D