Answer:
A:Boyle's Law or B:Charles's Law
Explanation:
Powdered coke prevent the heat loss. As a result, it prevents burning of carbon electrodes.
Answer: The standard enthalpy of formation of
is -252.1 kJ/mol.
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
Putting the values we get :
Thus standard enthalpy of formation of
is -252.1 kJ/mol.
Answer:C
Explanation:
A process is called spontaneous if the process takes place on its own without the intervention of external factors.
The spontaneous processes are generally quick with observable rates of reaction.But processes can be spontaneous even with negligible rates of reaction.
Spontaneity of reactions depend on temperature.
This is because spontaneity is measured by gibbs energy or enthalpy.
Both of these measures are dependent on temperature.
So,temperature affects spontaneity.
Answer : The energy of the photon emitted is, -12.1 eV
Explanation :
First we have to calculate the
orbit of hydrogen atom.
Formula used :

where,
= energy of
orbit
n = number of orbit
Z = atomic number of hydrogen atom = 1
Energy of n = 1 in an hydrogen atom:

Energy of n = 2 in an hydrogen atom:

Energy change transition from n = 1 to n = 3 occurs.
Let energy change be E.

The negative sign indicates that energy of the photon emitted.
Thus, the energy of the photon emitted is, -12.1 eV