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.

(a) The formation of $CH_4$ will be,

$2C(coal)+2H_2O(g)\rightarrow CH_4(g)+CO_2(g)$ $\Delta H_{rxn}=?$

The intermediate balanced chemical reaction will be,

(1) $C(coal)+H_2O(g)\rightarrow CO(g)+H_2(g)$ $\Delta H_1=29.7kJ$

(2) $CO(g)+H_2O(g)\rightarrow CO_2(g)+H_2(g)$ $\Delta H_2=-41kJ$

(3) $CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)$ $\Delta H_3=-206kJ$

We are multiplying equation 1 by 2 and then adding all the equations, we get :

(b) The expression for enthalpy of reaction will be,

$\Delta H_{rxn}=2\times \Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H_{rxn}=(2\times 29.7)+(-41)+(-206)$

$\Delta H_{rxn}=-187.6kJ/mol$

Therefore, the enthalpy of reaction is, -187.6 kJ/mol

(c) Now we have to calculate the total heat.

$\Delta H=\frac{q}{n}$

or,

$q=\Delta H\times n$

where,

$\Delta H$ = enthalpy change = -187.6 kJ/mol

q = heat = ?

n = number of moles of coal = $\frac{1.00\times 1000g}{12.00g/mol}=83.33mol$

Now put all the given values in the above formula, we get:

$q=(-187.6kJ/mol)\times (83.33mol)=-2.251kJ$

Thus, the total heat will be, -2251 kJ

4 0

4 years ago

Ways to manage non-biodegradable waste

Lisa [10]

Answer:

The following are some ways of safely disposing of non-biodegradable waste.

1. Take them to a local recycling facility. Separate metal, plastic, glass, and other non-biodegradable waste and store them ready for recycling.

2. Combustion and energy recovery.

3. Disposal at sanitary facilities.

4. Reduce.

5. Landfills.

Explanation: Hope it helps! ^_^"

(G00gle)

7 0

3 years ago

Can Someone Please Help Me With This One Question

xz_007 [3.2K]

The engineer would C. research new scientific findings about ocean cleanup.

A competent engineer would already know what has been done in the past to clean up oceanic oil residue.

Identifying needs and evaluating benefits and challenges are <em>value judgements</em> that are more appropriate for other decision-makers such as politicians.

8 0

4 years ago

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