아세트산나트륨의 발열 결정화

순간 결정화에서 방출되는 열 측정하기

Thermochemistry Intermediate (High School) 30 분 ~$8.00

목표

열량 측정법으로 과포화 아세트산나트륨의 결정화에서 방출되는 열을 정량한다.

배경

When supersaturated sodium acetate crystallizes, it releases stored energy as heat. By triggering crystallization inside a calorimeter and measuring the temperature rise, the enthalpy of crystallization can be determined. This is the same principle used in reusable hand warmers.

안전 경고

  • Hot solution during preparation
  • Crystallization releases heat — container gets warm

필수 개인 보호 장비

goggles

재료

  • Sodium acetate trihydrate (80 g)
  • Distilled water (150 mL)

장비

Polystyrene cup calorimeter Hot plate Thermometer Beaker (250 mL) Stirring rod

실험 절차

1

Dissolve 80 g sodium acetate trihydrate in 20 mL water by heating to about 70°C. Stir until clear.

8 분 Handle hot solution carefully
2

Pour the solution into the polystyrene cup calorimeter. Allow to cool undisturbed to room temperature.

15 분
3

Record the temperature of the supersaturated solution.

1 분
4

Add a single small crystal of sodium acetate to trigger crystallization. Immediately stir gently and record temperature every 15 seconds.

3 분
5

Record the maximum temperature reached.

1 분
6

Calculate the heat released: q = mcΔT. Determine ΔH of crystallization per mole.

5 분

예상 결과

Temperature should rise 15-25°C above room temperature. The enthalpy of crystallization is approximately -19.7 kJ/mol for sodium acetate trihydrate. Measured values should be within 20% of this.

정리

The sodium acetate can be remelted and reused. Rinse the calorimeter. Non-toxic — can go down the drain.

세부 정보

카테고리
Thermochemistry
난이도
Intermediate (High School)
소요 시간
30 분
예상 비용
$8.00
단계
6
재료
2

더 많은 실험

마그네슘의 연소열 50 min 금속의 비열 용량 40 min 커피컵 열량 측정 40 min 헤스의 법칙 검증 60 min 얼음의 융해 엔탈피 25 min 용해는 항상 발열이 아니다 25 min 냉찜질 팩의 화학 원리 20 min 폭탄 열량계 시뮬레이션 45 min 흡열 반응 실험 20 min

Frequently Asked Questions

What is the objective of 아세트산나트륨의 발열 결정화?
열량 측정법으로 과포화 아세트산나트륨의 결정화에서 방출되는 열을 정량한다.
How difficult is 아세트산나트륨의 발열 결정화?
This experiment is rated as Intermediate (High School). It takes approximately 30 minutes to complete.
What safety precautions are needed for 아세트산나트륨의 발열 결정화?
Key safety precautions include: Hot solution during preparation; Crystallization releases heat — container gets warm.
What materials are needed for 아세트산나트륨의 발열 결정화?
The main materials required are: Sodium acetate trihydrate, Distilled water.
What results should I expect from 아세트산나트륨의 발열 결정화?
Temperature should rise 15-25°C above room temperature. The enthalpy of crystallization is approximately -19.7 kJ/mol for sodium acetate trihydrate. Measured values should be within 20% of this.