Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole
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 equations, we get :
(1) 
(2) 
(3) 
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole
They define acids as proton donors, and bases as proton acceptors
If you were to have:
HNO3 + H2O -> H3O+. + NO3-
You can see that the nitric acid (HNO3) gave a hydrogen ion which has 1 proton, 0 neutrons and 0 electrons to the water so we just say that it gave a proton.
Now let's see a base
NH3 + H2O -> NH4+ + OH-
Now, you can see that the ammonia (NH3) gained a hydrogen ion (proton) from the water to become ammonium(NH4). which means it accepted a proton
That's basically it. Feel free to ask if you have any further questions
Answer:
A luminous ball of gas in space
Explanation:
This luminous ball of gas is held by its own gravity.
Answer:
A.
Explanation:
melting of ice will increase water in oceans due to which water in oceans will increase and salinity will decrease. hence, melting of ice caps near the north pole affects salinity of the ocean
Discharge is measured in cubic meters per second.
