Answer:
2 moles
Step-by-step explanation:
Mole:
Mole is the unit of amount in chemistry. It is SI unit and represented by "mol".
Example:
one mole of hydrogen has a mass of 1.008 g and contain 6.022× 10∧23 atoms.
Steps to find the number of moles:
1. If the number of grams are given then to find out the moles first of all we will find the molar mass of given chemical substance.
For example:
If the given chemical substance is NaOH then its molecular weight is determine through following way:
atomic mass of Na= 1×22.989 g/mol
+
atomic mass of oxygen= 1×16 g/mol
+
atomic mass of hydrogen= 1× 1.008 g/mol
molecular mass of NaOH= 39.97 or 40 g/mol
2. when the molar mass and grams are known then number of moles are determine through following formula:
number of moles= mass in gram/ molar mass (g/mol)
Given data:
Now we will put the values in formula,
number of moles= 8.00g/4 g/mol
number of moles= 2 mol