Chapter 5, Problem 113SCQ

(a)

Interpretation Introduction

Interpretation:

The internal energy for the oxidation of $\text{Mg}$ has to be determined

Concept Introduction:

Heat energy required to raise the temperature of 1g of substance by 1K..Energy gained or lost can be calculated using the below equation.

  $\text{q=C×m×ΔT}$

Where, q= energy gained or lost for a given mass of substance (m), C =specific heat capacity, $\text{ΔT}$= change in temperature.

Sum of all energies transferred as heat in the system

  ${\text{q}}_{\text{r}}$ $\text{+}$ ${\text{q}}_{\text{bomb}}$ $\text{+}$${\text{q}}_{\text{water}}$$\text{=0}$

(b)

Interpretation Introduction

Interpretation:

The change in internal energy in the system has to be calculated.

Concept Introduction:

Standard enthalpy of the reaction,${\text{Δ}}_{\text{r}}{\text{H}}^{\text{o}}$, is the change in enthalpy that happens when matter is transformed by a given chemical reaction, when all reactants and products are in their standard states.

Enthalpy change for the reaction ${\text{Δ}}_{\text{r}}{\text{H}}^{\text{0}}$=${\text{ΣnΔ}}_{\text{f}}{\text{H}}^{\text{0}}\text{(products)}\text{-}{\text{ΣnΔ}}_{\text{f}}{\text{H}}^{\text{0}}\text{(reactants)}$