Question

How many grams of NaCl present in 1 mole?
A) 58.5 g
B) 108 g
C) 85.7 g
D) 74.6 g

Answer 1

To find how many grams present have to find atomic weight of Na and Cl then we have to find molecular weight, which is the required answer.

Complete answer:
The Atomic weight of Na is 23 g and Atomic weight of Cl is 35.5 gm.
Atomic mass of an element is the mass of the atoms of an element measured in atomic mass units.
1 mol of Na = 23 gm of Na.
1 mol of Cl = 35.5 gm of Cl.
Now, 1 mol of NaCl = Atomic mass of Na + Atomic mass of Cl
= 23 + 35.5
= 58.5 g
$\therefore$ We can say 58.5 g of NaCl present in 1 mole.

$\therefore$ option A is correct.

Note: To solve this type of problem we have to go know the atomic weight of the respective elements. Mendeleev in 1859, who published this table by arranging atomic weight of the atoms in increasing order. So if we are going to read the periodic table we gradually get to know about the atomic weight or atomic mass of the respective elements.