What volume of each of the following bases will react completely with \(25.00 \mathrm{mL}\) of \(0.200 \mathrm{M}\) HCl? a. \(0.100 M\) NaOH c. \(0.250 M\) KOH b. \(0.0500 M \operatorname{Sr}(O H)_{2}\)

Understanding stoichiometry is essential for mastering acid-base titration calculations. Stoichiometry is the study of the quantitative relationships between the amounts of reactants used and products formed in a chemical reaction, based on the balanced chemical equations. A stoichiometric amount describes the exact proportion of reactants needed to react without any excess.

For instance, the reaction between NaOH and HCl has a stoichiometric coefficient of 1 for both reactants, indicating a 1:1 ratio. In other words, one mole of NaOH will react with one mole of HCl to produce one mole of NaCl and one mole of water. When you know the stoichiometry of a reaction, you can precisely determine the volume of another reactant needed to completely react with a known quantity of one reactant, which is often the goal in titration.

Molarity is a measure of the concentration of a solute in a solution and is defined as the number of moles of solute per liter of solution. It is denoted as M and is a crucial concept in titration because it allows chemists to relate the volume of a solution to the amount of substance in moles.

The formula to calculate molarity is given by:
\( \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{liters of solution}} \).

For example, if you have a solution of NaOH with a molarity of 0.100 M, this means each liter of solution contains 0.100 moles of NaOH. By knowing the molarity and the volume of the solution, you can calculate the number of moles present, which is vital for figuring out how much of another substance will react with it in a titration process.

Balanced chemical equations are representations of chemical reactions where the number of atoms for each element is the same on both the reactant and product sides of the equation. This balance is a requirement because of the law of conservation of mass.

When writing equations for titration reactions, it’s essential that they are balanced in order to correctly perform moles calculation and stoichiometry. Take the example of the reaction between HCl and NaOH forming NaCl and H2O:
\( \text{NaOH + HCl} \rightarrow \text{NaCl + H2O} \).

In this equation, each element has the same number of atoms on both sides, making the equation balanced. The balanced equation tells us that one mole of NaOH reacts with one mole of HCl, which is fundamental information when calculating how much of one reactant is needed to completely react with a given amount of another.

The calculation of moles is a fundamental part of chemical reactions and titration. The mole is a standard unit in chemistry that measures the amount of a substance. One mole is defined as exactly 6.02214076×10²³ elementary entities (usually atoms or molecules).

In acid-base titration calculations, you often start by determining the number of moles in a given volume of solution through the formula:
\( \text{moles} = \text{volume in liters} \times \text{molarity} \).

Thus, for a sample containing 25.00 mL of 0.200 M HCl, convert the volume to liters (0.025 L), then multiply by the molarity to find the moles of HCl:
\( \text{moles of HCl} = 0.025 \text{ L} \times 0.200 \text{ M} = 0.00500 \text{ moles} \).

This calculation is crucial because it allows you to determine how much of another reactant you’ll need to complete the reaction, as seen when you use stoichiometry to calculate the volume of NaOH required to react with the HCl.