Titrasi Asam-Basa (kimia SMA kelas 11 semester 2)

Summary

This video tutorial covers acid-base titration, a method used to determine the concentration of an unknown solution by reacting it with a solution of known concentration. The process involves using key equipment such as a burette, Erlenmeyer flask, and an indicator to identify the endpoint of the reaction. The script explains essential terms like titrant, titrate, indicator, equivalence point, and endpoint, while also providing step-by-step procedures for performing the titration. The video includes practical examples and calculations to demonstrate how to calculate the concentration of acids and bases from titration results.

Takeaways

• 😀 Acid-base titration is a method used to determine the concentration of an unknown acid or base solution by reacting it with a solution of known concentration.
• 😀 Titration involves the use of a titrant (standard solution), a titrate (substance being analyzed), and an indicator to visually detect the endpoint of the reaction.
• 😀 The titrant is placed in a burette, and the titrate is placed in an Erlenmeyer flask. The titrant is slowly dripped into the titrate until a color change indicates the endpoint.
• 😀 An indicator is added to the titrate solution to signal the endpoint of the titration when the solution changes color.
• 😀 The endpoint of the titration occurs when the indicator changes color, signaling that the reaction is complete.
• 😀 The equivalence point is where the moles of acid and base are equal, which is key in calculating the concentration of the unknown solution.
• 😀 The concentration of the titrate can be calculated using the formula: (M1 × V1 × N1) = (M2 × V2 × N2), where M is molarity, V is volume, and N is the valence.
• 😀 In a titration of HCl with NaOH, the concentration of HCl can be determined by calculating the ratio of volume and molarity of NaOH to the known volume of HCl.
• 😀 Example: In the titration of HCl, if 25 mL of HCl is titrated with 30 mL of NaOH (0.1 M), the concentration of HCl is calculated to be 0.12 M.
• 😀 In another example, titrating 20 mL of H2SO4 with NaOH (0.1 M), the concentration of H2SO4 was calculated to be 0.075 M using the titration data.
• 😀 To obtain more accurate results in titration, multiple trials can be conducted. For example, by averaging the volumes of NaOH used in three titrations, the concentration of HCl was found to be 0.15 M.

Q & A

What is the main purpose of acid-base titration?

The main purpose of acid-base titration is to determine the concentration of an acid or base solution whose concentration is not yet known, using a solution with a known concentration.

What is titrant, and where is it placed during titration?

A titrant is a substance whose concentration is known with certainty. During titration, the titrant is placed in a burette.

What is the function of the indicator in an acid-base titration?

The indicator is a substance that changes color when acid or base is added. Its role is to signal the end point of the titration by indicating when the titration should be stopped.

What is the difference between the end point and the equivalence point in titration?

The end point of titration is when the indicator changes color, signaling that the titration should be stopped. The equivalence point is when the moles of acid equal the moles of base in the reaction.

What equipment is commonly used for acid-base titration?

The common equipment for acid-base titration includes an Erlenmeyer flask, a burette, clamps, and stands. The burette holds the titrant, and the Erlenmeyer flask holds the titrate.

How is the concentration of an unknown solution calculated during titration?

The concentration of the unknown solution is calculated using the formula: MₐVₐ = MᵦVᵦ, where M is molarity and V is the volume of the acid (ₐ) and base (ᵦ), adjusted for their valences.

What does the term 'valence' refer to in the context of titration?

In titration, 'valence' refers to the number of hydrogen ions (H⁺) in an acid or hydroxide ions (OH⁻) in a base. It determines how many moles of acid or base react with each other.

In the titration example with HCl and NaOH, what is the concentration of HCl?

The concentration of HCl is calculated as 0.12 mol/L after titrating 25 mL of HCl with 0.1 M NaOH and reaching the end point after 30 mL of NaOH was added.

What happens during the titration of H₂SO₄ with NaOH in the second example?

During the titration of H₂SO₄ with NaOH, 20 mL of H₂SO₄ is titrated with 0.1 M NaOH, and the endpoint is reached after adding 30.2 mL of NaOH. The concentration of H₂SO₄ is calculated as 0.075 M.

How do you calculate the average volume of NaOH used in titration experiments?

To calculate the average volume of NaOH used, add up the volumes from multiple trials and divide by the number of trials. For example, (31 + 30 + 32) / 3 = 31 mL.