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
Answer: Option (d) is the correct answer.
Explanation:
The amount of salt present or dissolved in water or water body is known as salinity.
When salinity increases then number of particles increases, therefore, density will increase. Also, number of ions will decrease thus, electrical conductivity will decrease.
On the other hand, increase in salinity will increase the amount of salt (NaCl) is the water.
Thus, we can conclude that out of the given options, the option all of the above is true.
I think the correct answer from the choices listed above is option D. When a molecular compound melts, they undergo the process of phase change from solid to liquid therefore m<span>olecules arranged in a regular pattern change to an irregular pattern. Hope this answers the question.</span>
Answer:
talc mineral and magnetite
Explanation:
Answer: ?
Explanation: I translated this and It makes no sense.
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