The answer is •c•
Hope this is correct I tried
If the reaction is represented by:
PCl₃ + Cl₂ <-> PCl₅ (exothermic)
the mole fraction of chlorine in the equilibrium mixture will change according to the following:
Decrease the volume: decrease
Increase the temperature: increase
Increase the volume: increase
Decrease the temperature: decrease
Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
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Elements in the same period have the same number of electron shells.
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Metallic elements become less reactive as you move left to right in a period.
-
Metallic elements become more reactive as you move top to bottom in a group.
Answer: 
Explanation:
A single displacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

Synthesis reaction is defined as the reaction where substances combine in their elemental state to form a single compound.
Decomposition reaction is defined as the reaction where a single substance breaks down into two or more simpler substances.

Combustion is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.

Answer:
I. The balloon has a volume of 22.4L
III. The balloon contains 6.022x10^23 molecules.
Explanation:
At stp, it has been proven that 1mole of a gas occupy 22.4L.
Therefore, option (i) is correct.
The molar mass N2 = 14.01 x 2 = 28.02g/mol
Number of mole of N2 = 1 mole
Mass of N2 =..?
Mass = mole x molar Mass
Mass of N2 = 1 x 28.02 = 28.02g.
The mass content of the balloon is 28.02g, therefore, option (ii) is wrong.
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02x10^23 molecules. This implies that 1 mole of N2 also contains 6.02x10^23 molecules
Therefore, option (iii) is correct.
The correct options to the question are:
Option i and option iii