Question

Find the number of moles of ‘X’ atoms in $93g$ of X. [X is phosphorous=$31$]

Answer 1

We can use of formula of number of moles of phosphorus using the formula given as-
$\Rightarrow$n=$\dfrac{W}{M}$
Where n is the number of moles of the element, W is the given mass of the element and M is the molecular mass of the element. Put the given values in the formula and divide the numerator by denominator to get the answer.

Complete step by step answer:
We have to find the number of moles of X atoms in $93g$ of X.
Given, the X is phosphorous whose atomic mass is $31$.
Now we know that the formula of number of moles is-
$\Rightarrow$n=$\dfrac{W}{M}$
Where n is the number of moles of the element, W is the given mass of the element and M is the molecular mass of the element.
Then it is given that W=$93g$ and M=$31$g.
On putting these values in the formula, we get-
$\Rightarrow$n=$\dfrac{{93}}{{31}}$
On division, we get-
$\Rightarrow$n=$3$

The number of moles of phosphorus in $93g$ of phosphorous is $3$

Additional Information:
Phosphorus is an element which does not exist in nature in the Free State, it is always found in a combined state. Its two main forms exist-
Red Phosphorous- which is an amorphous solid. It is an allotrope of phosphorus which is deep red in color. It is non-toxic. It is also more stable than white phosphorus.
White Phosphorous-It is a waxy solid which is poisonous in nature. It glows in the dark and is flammable when it reacts with oxygen present in the air.

Note:
Phosphorus is used as-
-Red phosphorus is used as a flame retardant in thermosetting polymers.
-It is used as a smoke device that quickly creates a smoke screen.
-It is used in making emergency flares.
-White phosphorus is used in incendiary devices.
-Phosphorus is also used as fertilizer and in production of steel.