6. 8.50 ml of a standardized 0.05120mol/L silver nitrate solution was used to titrate 10.00 ml of ammonium thiocyanate solution. Calculate the molar concentration of ammonium thiocyanate solution

To calculate the molar concentration of the ammonium thiocyanate solution, we can use the concept of stoichiometry and the fact that the reaction between silver nitrate (AgNO₃) and ammonium thiocyanate (NH₄SCN) is a 1:1 molar ratio.<br /><br />The balanced chemical equation for the reaction is:<br />\[ \text{AgNO}_3 + \text{NH}_4\text{SCN} \rightarrow \text{AgSCN} + \text{NH}_4\text{NO}_3 \]<br /><br />Given:<br />- Volume of silver nitrate solution (\(V_{\text{AgNO}_3}\)) = 8.50 mL<br />- Molarity of silver nitrate solution (\(M_{\text{AgNO}_3}\)) = 0.05120 mol/L<br />- Volume of ammonium thiocyanate solution (\(V_{\text{NH}_4\text{SCN}}\)) = 10.00 mL<br /><br />First, calculate the number of moles of silver nitrate used in the titration:<br />\[ \text{moles of AgNO}_3 = M_{\text{AgNO}_3} \times V_{\text{AgNO}_3} \]<br />\[ \text{moles of AgNO}_3 = 0.05120 \, \text{mol/L} \times 0.00850 \, \text{L} \]<br />\[ \text{moles of AgNO}_3 = 0.0004356 \, \text{mol} \]<br /><br />Since the reaction is a 1:1 molar ratio, the moles of ammonium thiocyanate will be the same as the moles of silver nitrate:<br />\[ \text{moles of NH}_4\text{SCN} = 0.0004356 \, \text{mol} \]<br /><br />Now, calculate the molar concentration of the ammonium thiocyanate solution:<br />\[ M_{\text{NH}_4\text{SCN}} = \frac{\text{moles of NH}_4\text{SCN}}{V_{\text{NH}_4\text{SCN}}} \]<br />\[ M_{\text{NH}_4\text{SCN}} = \frac{0.0004356 \, \text{mol}}{0.01000 \, \text{L}} \]<br />\[ M_{\text{NH}_4\text{SCN}} = 0.04356 \, \text{mol/L} \]<br /><br />Therefore, the molar concentration of the ammonium thiocyanate solution is \(0.04356 \, \text{mol/L}\).