Answer:
These first and the last are examples of reversible reactions:
- Iodine and chlorine can react to form iodine chloride. At equilibrium, the system contains a mixture of iodine, chlorine, and iodine chloride.
- Hydrogen and nitrogen react to form ammonia. At low pressure, the equilibrium system contains all three substances.
Explanation:
The reactions that end in a quasi complete conversion of the reactants into the products are said that are not reversible reactions.
Most of the chemical reactions do not reach a complete conversion. They seem to stop without getting complete conversion. The reason is that these reactions are reversible. A reversible reaction is that that can be forward (direct reaction) and backward (inverse or reverese reaction). In these cases, when the equilibrium is reached the rates of the forward and reverse reactions are equal, which explain why the reaction seems to stop, and a mixture of products and reactants will remain.
The two examples of reversible reactions given may be represented in this way:
1) Iodine and chlorine can react to form iodine chloride. At equilibrium, the system contains a mixture of iodine, chlorine, and iodine chloride.
- Forward reaction: I₂ (g) + Cl₂ (g) → 2ICl (g)
- Reverse reaction: I₂ (g) + Cl₂ (g) ← 2ICl (g))
- Combined reaction: I₂ (g) + Cl₂ (g) ⇄ 2ICl (g)
The double arrow is used to indicate that the reaction is reversible. In the forward reaction, iodine and chlorine react to form iodine chloride, in the reverse reaction iodine chlorice decomposes to form the substances iodine and chlorine.
2) Hydrogen and nitrogen react to form ammonia. At low pressure, the equilibrium system contains all three substances.
- Forward reaction: 3H₂ (g) + N₂ (g) → 2NH₃ (g)
- Reverse reaction: 3H₂ (g) + N₂ (g) ← 2NH₃ (g)
- Combined reaction: 3H₂ (g) + N₂ (g) ⇄ 2NH₃ (g)
In the foward reaction, hydrogen a nitrogen combine to form amonia, in the reverse reaction ammonia decomposes producing the substances hydrogen and nitrogen.
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Answer : Option B) Attempt to control the conditions.
Explanation : While conducting an experiment, a scientist should always attempt to control the reaction conditions.
If the reaction conditions are not controlled one can lose the expected result or observation that was supposed to be generated from the experiment. Like controlling the given temperature, pressure, addition of catalysts, etc. If these conditions are overlooked one may not achieve the expected results and will not reach to the conclusion.
Answer:
Masses of bromobenzene molecular ions will occur at 156 and 158 m/z.
Explanation:
The molecular ion peak is the signal in the mass spectrum of a compound that represents the molecular ion (denoted as M). Compounds that are composed of atoms having abundant isotope also shows M +1 and M+2 peaks (depending on the isotope).
In the given bromobenzene compound, an atom of bromine is present. The two isotopes with considerable relative abundance of Br are 79Br and 81Br with a difference of two units in their mass. This means that two molecular ion peaks with a difference of two units will appear in the mass spectrum. The mass of the whole compound is 156 amu. Hence, the molecular ion peaks will appear at 156 m/z and 158 m/z due to the two isotopes of bromine.
When nuclear fusion reaction takes place, matter is converted to energy.