Question

Find out the number of molecules in $2.5$ moles of water.

• A. $2.5N_A$
• B. $20N_A$
• C. $10N_A$
• D. $25N_A$

Answer 1

The correct option is A $2.5N_A$

As we know, one mole of each substance contains $N_A=6.023\times {10}^{23}$ molecules

So $2.5$ moles water will have $N=2.5\times 6.023\times {10}^{23}=15\times {10}^{23}$ molecules.