Explanation:
According to the mole concept, there are atoms or molecules present in 1 mole.
As, it is given that mass of ethyne is 84.3 g. Hence, calculate its number of moles as follows.
No. of moles =
=
= 3.24 mol
Therefore, calculate number of ethyne molecules as follows.
atoms
= atoms
Thus, we can conclude that there are atoms in 84.3 grams of ethyne.
Answer:
1. 2+ ().
2. 0 ().
Explanation:
Hello,
In this case, the described chemical reaction is a redox reaction in fact, since the oxidation states of both magnesium and copper change as shown due to the displacement:
Therefore:
1. Since copper is the cation in the copper (II) nitrate, the (II) means that its charge is 2+ ().
2. Since copper is alone, it means no electrons are being neither shared not given, its charge is 0 ().
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Answer: Option (C) is the correct answer.
Explanation:
When chemical composition of a substance is not changing in a chemical reaction then it is known as a physical change.
For example, when water change state, from ice to steam then it means solid state is changing into gaseous state.
Therefore, it is a physical change.
And, a reaction which causes change in chemical composition is known as a chemical change.
For example,
Thus, we can conclude that we can see water change state, from ice to steam. This is a physical change in matter.