determine the molar mass of hx.equation NaOH(aq)+Hx(aq) arrow Max (aq)+H2O(I). titrant =0.09156m vial before =7.4514g vial after =6.9225g. hx sample=0.4918. titrant is sodium hydroxide which have a concentration of 0.09156 and the titrant volume is 37.1ml

Answer 1

To calculate the molar mass of \( Hx \) based on the titration with sodium hydroxide (NaOH), we will follow these steps:

Step 1: Determine the Moles of NaOH Used

First, we need to find out how many moles of NaOH were used in the titration. The concentration of the NaOH solution is given, along with the volume used in the titration.

1. Convert the volume of NaOH from mL to L: \[ \text{Volume of NaOH} = 37.1 , \text{mL} = \frac{37.1}{1000} , \text{L} = 0.0371 , \text{L} \]

2. Calculate the moles of NaOH: \[ \text{Moles of NaOH} = \text{Concentration} \times \text{Volume} = 0.09156 , \text{mol/L} \times 0.0371 , \text{L} \] \[ \text{Moles of NaOH} = 0.003397 , \text{mol} , (\text{approximately}) \]

Step 2: Determine the Moles of Hx

From the balanced equation: \[ \text{NaOH(aq) + Hx(aq) → Max(aq) + H2O(l)} \] The stoichiometry is 1:1, meaning that the moles of \( Hx \) will be equal to the moles of \( NaOH \).

\[ \text{Moles of } Hx = 0.003397 , \text{mol} \]

Step 3: Calculate the Molar Mass of Hx

To calculate the molar mass \( M \) of \( Hx \), we can use the formula: \[ M = \frac{\text{mass of } Hx}{\text{moles of } Hx} \]

1. Calculate the mass of \( Hx \): \[ \text{Initial mass of the vial} = 7.4514 , \text{g} \] \[ \text{Final mass of the vial} = 6.9225 , \text{g} \] \[ \text{Mass of } Hx = \text{Initial mass} - \text{Final mass} = 7.4514 , \text{g} - 6.9225 , \text{g} = 0.5289 , \text{g} \]

2. Now calculate the molar mass: \[ M = \frac{0.5289 , \text{g}}{0.003397 , \text{mol}} \approx 155.0 , \text{g/mol} \]

Conclusion

The molar mass of \( Hx \) is approximately 155.0 g/mol.