Succinic acid, an intermediate in the metabolism of food molecules, has a molecular weight of 118.1. When 1.926 g of succinic acid was dissolved in water and titrated, 65.20 mL of 0.5000 M NaOH solution was required to neutralize the acid. How many acidic hydrogens are there in a mol-ecule of succinic acid? (LO 4.16)(a) 1(b) 2 (c) 3 (d) 4

Verified step by step guidance

1. Determine the moles of NaOH used in the titration by using the formula: \( \text{moles of NaOH} = \text{volume (L)} \times \text{molarity (M)} \).
2. Calculate the moles of succinic acid present using the mass given and its molecular weight: \( \text{moles of succinic acid} = \frac{\text{mass (g)}}{\text{molecular weight (g/mol)}} \).
3. Use the stoichiometry of the neutralization reaction to relate the moles of NaOH to the moles of succinic acid. Assume the reaction is: \( \text{Succinic acid} + x \text{NaOH} \rightarrow \text{products} \).
4. Determine the value of \( x \) (the number of moles of NaOH per mole of succinic acid) by dividing the moles of NaOH by the moles of succinic acid.
5. The value of \( x \) corresponds to the number of acidic hydrogens in a molecule of succinic acid.

Key Concepts

Acid-Base Neutralization

Acid-base neutralization is a chemical reaction where an acid reacts with a base to produce water and a salt. In this context, succinic acid, a diprotic acid, reacts with sodium hydroxide (NaOH) to neutralize its acidic protons. The amount of base required for neutralization can help determine the number of acidic hydrogens in the acid.

Molarity and Volume Calculations

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution. In this problem, the volume of NaOH solution used in the titration and its molarity are crucial for calculating the moles of NaOH that reacted with succinic acid. This information is essential to determine how many moles of acidic protons were neutralized.

Stoichiometry of Titration

Stoichiometry involves the calculation of reactants and products in chemical reactions. In titration, the stoichiometric ratio between the acid and base allows us to infer the number of acidic hydrogens based on the moles of NaOH used. For a diprotic acid like succinic acid, the stoichiometry indicates that two moles of NaOH are needed to neutralize one mole of the acid.