Answer:
I don't know
Explanation:
mixture of iron powder and sulphur heated it glows because sulphur and iron are more reactive metals that they shine and sulphur can react with water produce fire it's write
Answer:
The standard enthalpy of formation of HgO is -90.7 kJ/mol.
Explanation:
The reaction between Hg and oxygen is as follows.

From the given,
Molar mass of HgO = 216.59 g/mol
Mass of HgO decomposed = 18.5 g
Amount of heat absorbed = 7.75 kJ
From the reaction,
The standard enthalpy of formation = 
During the decomposition of 1 mol of HgO , 90.7 kJ of energy absorbed.
For the formation of 1 mol of HgO , 90.7 kJ of energy is release
Therefore, the enthalpy of formation of mercury(II)Oxide is -90.7 kJ/mol
Because diffusion<span> is the process when molecules move to lower or higher concentration, so as the molecules move faster they are going to lower or high concentration faster.</span>