페놀프탈레인을 이용한 산염기 적정

표준 염기 용액으로 산의 농도 결정하기

Titrations Intermediate (High School) 45 분 ~$15.00

목표

페놀프탈레인을 지시약으로 사용하여 표준화된 수산화나트륨 용액으로 미지 농도의 염산 용액을 적정하고 농도를 결정한다.

배경

This classic acid-base titration demonstrates stoichiometric neutralization. HCl reacts with NaOH in a 1:1 molar ratio. Phenolphthalein turns pink above pH 8.2, providing a clear endpoint. Accurate burette technique and multiple trials are essential for reliable results.

안전 경고

  • NaOH is corrosive — avoid skin and eye contact
  • HCl is corrosive — handle with care
  • Wear safety goggles throughout
  • Wash any spills immediately with water

필수 개인 보호 장비

goggles gloves lab_coat

재료

  • Hydrochloric acid (HCl) (100 mL)
    Unknown concentration
  • Sodium hydroxide (NaOH) (100 mL)
    0.1M standardized
  • Phenolphthalein indicator (5 mL)
    1% in ethanol
  • Distilled water (500 mL)
    For rinsing

장비

50 mL burette Burette stand and clamp 250 mL Erlenmeyer flask 25 mL pipette Pipette filler White tile Wash bottle

실험 절차

1

Rinse the burette with a small amount of NaOH solution, then fill it to the 0 mL mark. Record the exact starting volume.

5 분 Handle NaOH carefully
2

Using the pipette and filler, transfer exactly 25.0 mL of the unknown HCl solution into the Erlenmeyer flask.

3 분
3

Add 2-3 drops of phenolphthalein indicator to the flask. The solution should remain colorless (acidic).

1 분
4

Place the flask on the white tile under the burette. Begin adding NaOH slowly while swirling the flask continuously.

5 분
5

As the endpoint approaches (pink color lingers longer), add NaOH drop by drop until a permanent pale pink color persists for 30 seconds.

5 분
6

Record the final burette reading. Calculate the volume of NaOH used.

2 분
7

Repeat the titration at least two more times for concordant results (within 0.10 mL).

15 분
8

Calculate the concentration of HCl using: C(HCl) = C(NaOH) x V(NaOH) / V(HCl).

5 분

예상 결과

The endpoint should show a clear transition from colorless to a persistent pale pink. Concordant titre values (within 0.10 mL) indicate good technique. The calculated concentration should match the expected value within experimental error.

정리

Drain the burette and rinse with distilled water. Neutralize waste solutions before disposal. Rinse all glassware thoroughly.

세부 정보

카테고리
Titrations
난이도
Intermediate (High School)
소요 시간
45 분
예상 비용
$15.00
단계
8
재료
4

더 많은 실험

과망간산칼륨 산화환원 적정 50 min 표백제의 아이오딘 적정 50 min 전도도 적정 50 min 제산제 정제의 역적정 60 min 메틸 오렌지를 이용한 산염기 적정 40 min 이중 지시약을 이용한 탄산염-중탄산염 혼합물 적정 55 min 침전 적정(모어법) 45 min 아이오딘을 이용한 비타민 C 적정 40 min EDTA 착화 적정을 이용한 물 경도 측정 45 min pH 적정 곡선 50 min

Frequently Asked Questions

What is the objective of 페놀프탈레인을 이용한 산염기 적정?
페놀프탈레인을 지시약으로 사용하여 표준화된 수산화나트륨 용액으로 미지 농도의 염산 용액을 적정하고 농도를 결정한다.
How difficult is 페놀프탈레인을 이용한 산염기 적정?
This experiment is rated as Intermediate (High School). It takes approximately 45 minutes to complete.
What safety precautions are needed for 페놀프탈레인을 이용한 산염기 적정?
Key safety precautions include: NaOH is corrosive — avoid skin and eye contact; HCl is corrosive — handle with care; Wear safety goggles throughout.
What materials are needed for 페놀프탈레인을 이용한 산염기 적정?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Phenolphthalein indicator, Distilled water.
What results should I expect from 페놀프탈레인을 이용한 산염기 적정?
The endpoint should show a clear transition from colorless to a persistent pale pink. Concordant titre values (within 0.10 mL) indicate good technique. The calculated concentration should match the expected value within experimental error.