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2 years ago

Which profile best describes the reaction C(s) + 2H2(g) → CH4(g), AH = -74.9 kJ?

Chemistry

2 answers:

katrin [286]2 years ago

8 0

Answer:

Option B. A

Explanation:

From the question given above, the following data were obtained:

C(s) + 2H₂ (g) —> CH₄ (g). ΔH = –74.9 kJ

From the reaction above, we can see that the enthalpy change (ΔH) is negative (i.e –74.9 KJ) which implies that the heat content of the reactants is greater than the heat content of the products. Thus, the reaction is exothermic reaction.

For an exothermic reaction, the energy profile diagram is drawn in such a way that the heat content of reactants is higher than the heat content of products because the enthalpy change

(ΔH) is always negative.

Thus, diagram A (i.e option B) gives the correct answer to the question.

enyata [817]2 years ago

3 0

Answer:

B. A

Explanation:

Graph A, I just took a quiz on a p e x and it was correct!:)

You might be interested in

A sample containing 16.93 metal pellets is poured into a graduated cylinder containing 11.2 of water, causing the water level in

mixer [17]

Answer:

<h3>The answer is 1.99 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 16.93 g

volume = final volume of water - initial volume of water

volume = 19.7 - 11.2 = 8.5 mL

We have

$density = \frac{16.93}{8.5} \\ = 1.9917647058...$

We have the final answer as

Hope this helps you

7 0

3 years ago

(a) ions in a certain volume of .20M NaCl (aq) are represented in the box above on the left. in the box above on the right, draw

mamaluj [8]

Answer:

The first picture attached is the diagram that accompanies the question.

The<u> second picture attached</u> is the diagram with the answer.

Explanation:

In the box on the left there are 8 Cl⁻ ions and 8 Na⁺ ions.

The dissociaton equation for NaCl(aq) is:

NaCl (aq) → Na⁺ (aq) + Cl⁻(aq)

The dissociation equation for CaCl₂ (aq) is:

CaCl₂ (aq) → Ca²⁺ (aq) + 2Cl⁻(aq)

A 0.10MCaCl₂ (aq) solution will have half the number of CaCl₂ units as the number of NaCl units in a 0.20M NaCl (aq) solution.

Thus, while the 0.20M NaCl (aq) solution yields 8 ions of Na⁺ and 8 ions of Cl⁻, the 0.10MCaCl₂ (aq) solution will yield 4 ions of Ca²⁺ (half because the concentration if half) and 8 ions of Cl⁻ (first take half and then multiply by 2 because the dissociation reaction).

Thus, your drawing must show 4 dots representing Ca²⁺ ions and 8 dots representing Cl⁻ ions in the box on the right.