Step-by-step explanation:
According to the mole concept there are 
 atoms or molecules are present in 1 mole of a substance.
 atoms or molecules are present in 1 mole of a substance. 
 Mathematically, 1 mole = 
 atoms or molecules
 atoms or molecules 
 Therefore, calculate the number of molecules present in 2.50 moles of 
 as follows.
 as follows. 
 
 
 
 = 
 molecules
 molecules
Thus, we can conclude that there are 
 molecules in 2.50 moles of
 molecules in 2.50 moles of 
 .
.