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:
ch3c(ch3)(oh)ch3
Explanation:
that should be the answer
Answer:
Explanation:
State symbols are used in chemical equations to delineate the state of matter in which the reaction is taking place.
They give a good perspective of the state of the reactants and products obtainable.
There are basically four states of matter in every chemical reaction:
- Solids are symbolized by small letter (s)
- Liquids are represented by (l)
- Gases are shown by (g)
- Aqueous solutions having water as the medium by (aq)
These symbols appear as subscript in front of the chemical species.
Answer:
CO32−
Explanation:
We have to consider the valencies of the polyatomic ions involved. Recall that it is only a polyatomic ion with a valency of -2 that can form a compound which requires two sodium ions.
When we look closely at the options, we will realize that among all the options, only CO32− has a valency of -2, hence it must be the required answer. In order to be double sure, we put down the ionic reaction equation as follows;
2Na^+(aq) + CO3^2-(aq) ---------> Na2CO3(aq)