Answer : The enthalpy change for the reaction is, 97.7 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 given main chemical reaction is,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

Now we are multiplying reaction 1 by 2 and reversing reaction 3 and then adding all the equations, we get :
(1)

(2)

(3)

The expression for enthalpy of main reaction will be,



Therefore, the enthalpy change for the reaction is, 97.7 kJ
Oxygen is the element. It has a total of 6 valence electrons.
1 Atomic mass unit is the mass of an atom or it caliberates mass on atomic scale. It is also expressed in dalton denoted by Da whereas Atomic mass unit is denoted by amu.
1 amu can be expressed in grams as follows:


For converting in grams,


Thus, mass of Te is 204.16 * 10^-2^4 g
Answer:
specific heat.
Explanation:
Definition:
The amount of heat required to raise the temperature of one gram of substance by one degree is called specific heat.
Formula:
Q = m. c. ΔT
Q = amount of heat required
m = mass of substance
c = specific heat of substance
ΔT = change in temperature
The substance with greater value of specific heat require more heat to raise the temperature while the substance with lower value will raise its temperature very quickly by absorbing smaller heat.
For example the beach sand gets hot very quickly because of lower specific heat of sand while water is colder than sand because of higher specific heat capacity.