For each of the following reactions, identify another quantity that is equal to delth degree rxn.
1. ch4(g) + 2o2(g) rightarrow co2(g) + 2h2o(i)
enathalpy of combustion of ch4
enthaply of formation of co2(g)
4x bond energy of c - h
- 4x bond energy of c - h
2. ch4(g) rightarrow c(g) + 4h(g)
enthalpy of combustion of ch4
enthalpy of formation of c(g)
4x bond energy of c - h
- 4x bond energy of c - h
3. c(graphite) + 2h2(g) rightarrow ch4(g)
enthalpy of comusion of ch4
enthalpy of formation of ch4(g)
4x bond energy of c - h
- 4x bond energy of c - h
4. c(g) + 4h(g) rightarrow ch4(g)
enthalpy of comusion of c
enthalpy of formation of ch4(g)
4x bond energy of c - h
- 4x bond energy of c - h

1)

Enthalpy of combustion.

2)

4x bond energy of C - H

3)

enthalpy of formation of CH₄(g)

4)

- 4x bond energy of C - H

Explanation:

The enthalpy of reaction is the heat change during the reaction.

It can be:

a) Enthalpy of combustion : the heat change during complete burning of one mole of a substance in presence of oxygen.

b) Enthalpy of formation: the heat change during formation of one mole of a substance from its constituent elements in their native state.

c) The difference in the bond energies of reactants and products.

For:

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.