Question

a chemistry student weighs out 0.0720 g of formic acid (hcho₂) into a 250. ml volumetric flask and dilutes to the mark with distilled water. he titrate the acid with 0.1900m naoh solution. calculate the volume of naoh solution the student will need to add to reach the equivalence point. be sure your answer has the correct number of digits. ml

Explanation:

Step1: Calculate the moles of formic acid

The molar mass of \(HCHO_2\) is \(M=(1\times2 + 12+16\times2)\space g/mol=46\space g/mol\).
The moles of \(HCHO_2\), \(n=\frac{m}{M}\), where \(m = 0.0720\space g\) and \(M = 46\space g/mol\).
\(n=\frac{0.0720\space g}{46\space g/mol}\approx1.565\times 10^{-3}\space mol\)

Step2: Determine the mole ratio from the chemical reaction

The reaction between formic acid \((HCHO_2)\) and \(NaOH\) is \(HCHO_2+NaOH
ightarrow NaCHO_2 + H_2O\). The mole ratio of \(HCHO_2:NaOH = 1:1\)

Step3: Use the formula \(n = C\times V\) to find the volume of \(NaOH\)

We know \(n_{NaOH}=n_{HCHO_2}=1.565\times 10^{-3}\space mol\) and \(C_{NaOH}=0.1900\space M\)
From \(V=\frac{n}{C}\), substituting the values: \(V=\frac{1.565\times 10^{-3}\space mol}{0.1900\space mol/L}\)
\(V = 8.24\times10^{-3}\space L\)

Step4: Convert liters to milliliters

Since \(1\space L=1000\space mL\), \(V = 8.24\times10^{-3}\space L\times1000\space mL/L = 8.24\space mL\)

Answer:

\(8.24\space mL\)