Question

The number of glucose molecules present in $10ml$ of decimolar solution is:

• A. $6.0\times {10}^{20}$
• B. $6.0\times {10}^{19}$
• C. $6.0\times {10}^{21}$
• D. $6.0\times {10}^{22}$

Answer 1

The correct option is A $6.0\times {10}^{20}$

Given, Molarity $=0.1M;V=10ml=0.01litre$

Number of moles $=Molarity\times volume$ (in liters)

$=0.1\times 0.01$

$={10}^{-3}moles$

Number of Molecules $=moles\times Avogadronumber\left(N_A\right)$

$={10}^{-3}\times 6.0\times {10}^{23}$

$=6\times {10}^{20}molecules$

So, the correct option is $A$