Answer : The standard enthalpy of formation of ethylene is, 52.4 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of
will be,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equation, we get :
(1)

(2)

(3)

The expression for enthalpy of formation of
will be,



Therefore, the standard enthalpy of formation of ethylene is, 52.4 kJ
Answer:
The answer is True
Explanation:
Forensic toxicology involves or employs or uses disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation.
Answer:
When the metal reacts with hot, concentrated sulphuric acid, the products of the reaction are copper (II) sulphate, sulphur dioxide and water. Cu + 2H2SO4 = CuSO4 + SO2 + 2H2O. This is a typical redox reaction in which the acid is reduced to SO2, but no hydrogen is produced here
Answer:
Sand
Explanation:
with salt distillation will work, heat the solution and collect the water in a seperate beaker
With sugar you do the same, boil away the water and collect the water vapour, you'll be left with sugar in the original container and water if you collected it
Use a fraction of column and heat the solution, the alcohol will be seperated out
Sand is the only one that uses mechanical filtration
<span><span><span> </span><span>The strong forces oppose the electromagnetic force of repulsion between protons. Like ”glue” the strong force keeps the protons together to form the nucleus. </span>· The strong forces and electromagnetic forces both hold the atom together.</span><span> </span></span>