Kahve Kupası Kalorimetresi

Basit kalorimetreyle nötrleşme entalpisini ölçme

Thermochemistry Intermediate (High School) 40 dak ~$8,00

Hedef

Polistiren bardak kalorimetre kullanarak HCl ve NaOH'ın nötrleşme entalpisini belirlemek.

Arka Plan

A polystyrene cup makes an inexpensive but effective calorimeter because it has low thermal conductivity. By mixing known volumes of acid and base and measuring the temperature change, the enthalpy of neutralization can be calculated. The accepted value for strong acid-strong base neutralization is -57.1 kJ/mol.

Güvenlik Uyarıları

  • HCl and NaOH are corrosive
  • Wear safety goggles
  • The mixture will get hot

Gerekli KKD

goggles gloves lab_coat

Malzemeler

  • Hydrochloric acid (HCl) (50 mL)
    1M
  • Sodium hydroxide (NaOH) (50 mL)
    1M
  • Distilled water (100 mL)
    For calibration

Ekipman

Two polystyrene (Styrofoam) cups (nested) Cardboard lid with hole Thermometer (0.1°C resolution) Graduated cylinder (50 mL) Stopwatch

Prosedür

1

Measure 50 mL of 1M HCl and pour into the nested polystyrene cups. Record the initial temperature every 30 seconds for 3 minutes.

5 dak HCl is corrosive
2

Measure 50 mL of 1M NaOH in a separate container. Record its temperature.

2 dak NaOH is corrosive
3

Quickly pour the NaOH into the HCl, stir gently, and replace the lid with thermometer.

1 dak Exothermic reaction
4

Record the temperature every 30 seconds for 5 minutes. Note the maximum temperature.

5 dak
5

Plot temperature vs time. Extrapolate the cooling curve back to the mixing time to find the corrected maximum temperature.

5 dak
6

Calculate ΔT, then q = mcΔT (assume c = 4.18 J/g°C, mass = 100 g). Calculate ΔH per mole of water formed.

8 dak

Beklenen Sonuçlar

Temperature should rise by approximately 6-7°C. Calculated ΔH should be approximately -50 to -57 kJ/mol (accepted: -57.1 kJ/mol). Losses to the calorimeter walls typically give lower values.

Temizlik

The neutralized solution is safe to pour down the drain. Rinse and dry the calorimeter cups for reuse.

Ayrıntılar

Kategori
Thermochemistry
Zorluk
Intermediate (High School)
Süre
40 dak
Tahmini Maliyet
$8,00
Adımlar
6
Malzemeler
3

Daha Fazla Deney

Bomba Kalorimetresi Simülasyonu 45 min Buzun Erime Entalpisi 25 min Çözünme Her Zaman Ekzotermik Değildir 25 min Endotermik Tepkime Gösterisi 20 min Hess Yasasının Doğrulanması 60 min Magnezyumun Yanma Isısı 50 min Metallerin Özgül Isı Kapasitesi 40 min Sodyum Asetatın Ekzotermik Kristallenmesi 30 min Soğuk Paket Kimyası 20 min

Frequently Asked Questions

What is the objective of Kahve Kupası Kalorimetresi?
Polistiren bardak kalorimetre kullanarak HCl ve NaOH'ın nötrleşme entalpisini belirlemek.
How difficult is Kahve Kupası Kalorimetresi?
This experiment is rated as Intermediate (High School). It takes approximately 40 minutes to complete.
What safety precautions are needed for Kahve Kupası Kalorimetresi?
Key safety precautions include: HCl and NaOH are corrosive; Wear safety goggles; The mixture will get hot.
What materials are needed for Kahve Kupası Kalorimetresi?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Distilled water.
What results should I expect from Kahve Kupası Kalorimetresi?
Temperature should rise by approximately 6-7°C. Calculated ΔH should be approximately -50 to -57 kJ/mol (accepted: -57.1 kJ/mol). Losses to the calorimeter walls typically give lower values.