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3 years ago

PLZ HELP!!! I WILL GUVE BRAINLIEST TO THE FIRST RIGHT ANSWER!!!!

Chemistry

1 answer:

romanna [79]3 years ago

8 0

I think that the answer you are looking for is B.

Hope it helps :)

Can I have brainliest please? I need it really bad.

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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

ddd [48]

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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4 years ago

What happens to a liquids melting/freezing point and boiling point when you dissolve a substance in it

Inessa [10]

It either increases or decreases the melting/freezing point.

8 0

4 years ago

When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate int

sesenic [268]

Answer:

The solution expected to contain the greatest number of solute particles is: A) 1 L of 1.0 M NaCl

Explanation:

The number of particles is calculated as:

a) For Ionic compounds:

molarity × volume in liters × number of ions per unit formula.

b) For covalent compounds:

molarity × volume in liters

The difference is a factor which is the number of particles resulting from the dissociation or ionization of one mole of the ionic compound.

So, calling M the molarity, you can write:

# of particles = M × liters × factor

This table show the calculations for the four solutions from the list of choices:

Compound kind Particles in solution Molarity # of particles

(dissociation) (M) in 1 liter

A) NaCl ionic ions Na⁺ and Cl⁻ 1.0 1.0 × 1 × 2 = 2

B) NaCl ionic ions Na⁺ anc Cl⁻ 0.5 0.5 × 1 × 2 = 1

C) Glucose covalent molecules 0.5 0.5 × 1 × 1 = 0.5

D) Glucose covalent molecules 1.0 1.0 × 1 × 1 = 1

Therefore, the rank in increasing number of particles is for the list of solutions given is: C < B = D < A, which means that the solution expected to contain the greatest number of solute particles is the solution A) 1 L of 1.0 M NaCl.

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3 years ago

What will be the pH of a buffer solution containing an acid of pKa7.5, with an acid concentration exactly one fourth of that of

I am Lyosha [343]

Answer: pH of buffer solution is 8.1

Explanation:

The formula for the Henderson–Hasselbalch equation is:

$pH=pK_a+\log\frac{[A^-]}{[HA]}$