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1 year ago

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A cough syrup contains 5.0% ethyl alcohol, c2h5oh, by mass. if the density of the solution is 0.9928 g/ml, determine the molarit

y of the alcohol in the cough syrup.

1 answer:

Reil [10]1 year ago

7 0

<span>You are given a cough syrup that contains 5.0% ethyl alcohol, c2h5oh, by mass and its density of the solution is 0.9928 g/ml. The molarity of the alcohol in the cough syrup is 21.55.</span>

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Coal gasification is a multistep process to convert coal into cleaner-burning fuels. In one step, a coal sample reacts with supe

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Answer :

The enthalpy of reaction is, -187.6 kJ/mol

The total heat will be, -2251 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.

(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

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2 years ago

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Vesnalui [34]

<span>2 KClO3(s) → 3 O2(g) + 2 KCl(s)

</span><span>Note: MnO2 (Manganese Dioxide) is not part of the reaction. A catalyst lowers the activation energy and increases both forward and reverse reactions at equal rates.
</span>
molar mass of KClO3 = 122.5
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Moles of O2 produce = $\frac{3}{2} \times 0.028$

= 0.042 moles

molar mass of O2 = 32

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1 year ago

Write the expression for the equilibrium constant Kp for the following reaction.Enclose pressures in parentheses and do NOT writ

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<u>Answer:</u> The expression for $K_p$ is written below.

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Equilibrium constant in terms of partial pressure is defined as the ratio of partial pressures of the products and the reactants each raised to the power their stoichiometric ratios. It is expressed as $K_p$

For a general chemical reaction:

$aA+bB\rightleftharpoons cC+dD$

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The partial pressure for solids and liquids are taken as 1.

For the given chemical equation:

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The expression for $K_p$ for the following equation is:

$K_p=\frac{(P NH_3)\times (P H_2S)}{(P NH_4HS)}$

The partial pressure of $NH_4HS$ will be 1 because it is solid.

So, the expression for $K_p$ now becomes:

$K_p=\frac{(P NH_3)\times (P H_2S)}{1}$

Hence, the expression for $K_p$ is written above.

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Answer:

Explanation:

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The second resonance structure diagram for the ion given in the question can be found in the attached diagram below.

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