Question

calculate the number of chloride ions in 100ml of 0.001M HCl solution

Answer 1

0.001M HCl of 100mL will have 0.001*0.1 moles = 10^-4 moles

1 mole of HCl contains 6*10^23 Cl- ions

Thus 10^-4 moles of will contain 6*10^19 number of Cl ions

Answer 2

Answer : The number of chloride ions in 100 ml of 0.001 M HCl solution are $6.022\times 10^{19}$.

Solution : Given,

Volume of HCl solution = 100 ml

Molarity of solution = 0.001 mole/L

Molarity : It is defined as the number of moles of solute present in one liter of solution.

Formula used :

$Molarity=\frac{\text{ Moles of solute}\times 1000}{\text{ Volume of solution in liter}}$

Now put all the given values in this formula, we get moles of solute.

$0.001mole/L=\frac{\text{ Moles of solute}\times 1000}{100L}$

$\text{ Moles of solute}=0.0001moles=10^{-4}moles$

The moles of HCL = $10^{-4}moles$

1 mole of HCl Consists of 1 mole of $Cl^-$ ions and 1 mole of $H^+$ ions.

As, 1 mole of HCl contains $6.022\times 10^{23}$ chloride ions

$10^{-4}moles$ of HCl contains $(6.022\times 10^{23})\times (10^{-4})=6.022\times 10^{19}$ chloride ions

Therefore, the number of chloride ions in 100 ml of 0.001 M HCl solution are $6.022\times 10^{19}$.