molarity how i remember is mola( mole)rity
For the second answer I would think you would add all of the mass together
Hope that helps
Answer : The enthalpy change for the reaction is, 201.9 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 balanced reaction of will be,
The intermediate balanced chemical reaction will be,
(1)
(2)
(3)
(4)
Now we will multiply the reaction 1 by 2, revere the reaction 2, reverse and half the reaction 3 and 4 then adding all the equations, we get :
(1)
(2)
(3)
(4)
The expression for enthalpy of the reaction will be,
Therefore, the enthalpy change for the reaction is, 201.9 kJ
Answer:
a) Platinum > Beryllium > Aluminum > Magnesium > Potassium > Cesium
b) Cesium > Potassium > Magnesium > Aluminum > Beryllium > Platinum
c) Cesium > Potassium
Explanation:
We must recall that the frequency of an electromagnetic wave is directly proportional to its energy. Hence as the work function of the metal increases, the minimum frequency required for emission of electrons occur increases accordingly.
Similarly, the maximum wavelength required for electron emission to occur varies inversely as the work function of the metal hence the answer provided.
Lastly, only caesium and potassium has work function less than the energy of the incident photon hence only these two metals experience electron emission with the kinetic energy of electrons emitted from caesium greater than that emitted from potassium.