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AlladinOne [14]
3 years ago
5

Which step in the free-radical chlorination of methane do you expect to be the most exothermic? attempt this problem without loo

king at a table of bond dissociation enthalpies?
Chemistry
1 answer:
stiks02 [169]3 years ago
3 0

The termination step of the free-radical chlorination of methane is the most stable one among all three steps.

The free-radical substitution reaction between chlorine and methane features three major steps:

Initiation, during which chlorine molecules undergo homolytic fission to produce chlorine free radicals. Ultraviolet radiations are typically applied to supply the energy required for breaking the chlorine-chlorine single bonds. The initiation step is thus <em>endothermic</em>.

Propagation, a process in which chlorine free radicals react with methane molecules and remove a hydrogen atom from the alkane to produce hydrogen chloride and an alkyl radical e.g., \cdot \text{CH}_3. The carbon-containing free radical would react with chlorine molecules to produce chloromethane and yet another chlorine free radical. This process can well repeat itself to chlorinate a significant number of methane molecules.

Termination. Free radicals combine to produce molecules. For example, two chlorine free radicals would combine to produce a chlorine molecule, whereas two alkyl free radicals would combine to produce an alkane with two-carbon atoms in its backbone.

Chemical processes that increase the stability of a substance reduces its chemical potential energy. Energy conserves, thus such processes would also release energy equal to the potential energy lost in quantity. Free radicals are unstable and- as seen in the propagation step- compete readily with neutral molecules for their electrons. The propagation step keeps the number of free radicals constant and is therefore more exothermic than the initiation step. The termination step reduces the number of free radicals, increase the stability of the system by the greatest extent, and is therefore the most exothermic step among the three.

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Indicate whether each of the following statements is correct or incorrect.1)Every Bronsted-Lowry acid is also a Lewis acid2)Ever
Hunter-Best [27]

Answer:

1) correct

2) incorrect

3) correct

4)incorrect

Explanation:

1) A Lewis acid is a substance that accepts a nonbonding pair of electrons.

A Bronsted-Lowry acid is a substance that donates a proton H⁺

Since the donation of a proton involves the acceptance of a pair of electrons, every Bronsted-Lowry acid is also a Lewis acid.

2)A Lewis acid not necessarily needs to have a proton to be donated.

3) Conjugated acids of weak bases are strong acids and conjugated acids of strong bases are weak acids.

4)K⁺ comes from a strong base, therefore is does not have an acidic behaviour.

4 0
2 years ago
calculate δg o for each reaction using δg o f values: (a) h2(g) i2(s) → 2hi(g) 2.6 kj (b) mno2(s) 2co(g) → mn(s) 2co2(g) kj (c)
Reika [66]

(a)The change in Gibbs free energy for the reaction has been 2.6 kJ/mol.

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6 0
2 years ago
A man pours some hot coffee into a small cup from a large jug that contains enough coffee for several cups. Which statement corr
Stells [14]

Answer:

The correct answer is "The coffee in the jug has more thermal energy than the coffee in the cup".

Explanation:

First I had to look for the problem to know the possible answers.

In this case, the coffee jug has a large amount of coffee at the same temperature. If we analyze that the decanter and the coffee are at the same temperature, we have a homogeneous thermal system. The cup is at room temperature, so by pouring coffee into it, the temperature of the coffee decreases to balance with the temperature of the cup. At this moment, the temperature of the cup-cafe system is lower than the jug-cafe system.

Thermal energy is the part of the internal energy of an equilibrated thermodynamic system that is proportional to its absolute temperature and increases or decreases by energy transfer.

In this way, we can ensure that the thermal energy of the cup-cafe system is lower than that of the jug-cafe system.

Have a nice day!

3 0
3 years ago
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8 0
3 years ago
What is the most precise measurement this beaker can give?
allochka39001 [22]
<span>a.the nearest 1 ml

1 mL is much more precise than 100 mL because 1 mL is a very small and precise unit of measurement</span>
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