Answer:
<h2>0.64 moles </h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>0.64 moles</h3>
Hope this helps you
The law of conservation of mass states that mass cannot be created or destroyed. It can only be transformed/transferred from one form to another.
Answer:
6 moles of oxygen are needed to make 12 moles of magnesium oxide.
Explanation:
First of all you should know that the balanced chemical equation is:
2 Mg + O₂ → 2 MgO
The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:
a ⇒ b
c ⇒ x
So:

In this case the rule of three applies as follows: if 2 moles of magnesium oxide are produced from 1 mole of oxygen, 12 moles of magnesium oxide from how many moles of oxygen is produced?

moles of oxygen= 6
<u><em>6 moles of oxygen are needed to make 12 moles of magnesium oxide.</em></u>
Answer:
Answer : The number of atoms present in 159 g of calcium are
Explanation :
First we have to calculate the moles of calcium.
Molar mass of calcium = 40 g/mole
Now we have to calculate the number of atoms of calcium.
As, 1 mole of calcium contains number of atoms of calcium
So, 3.975 mole of calcium contains number of atoms of calcium
Therefore, the number of atoms present in 159 g of calcium are
Explanation: