Kalorimetri Cangkir Kopi

Mengukur entalpi penetralan menggunakan kalorimeter sederhana

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

Tujuan

Tentukan entalpi penetralan HCl dan NaOH menggunakan kalorimeter cangkir polistirena.

Latar Belakang

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.

Peringatan Keselamatan

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

APD yang Diperlukan

goggles gloves lab_coat

Bahan

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

Peralatan

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

Prosedur

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 menit HCl is corrosive
2

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

2 menit NaOH is corrosive
3

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

1 menit Exothermic reaction
4

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

5 menit
5

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

5 menit
6

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

8 menit

Hasil yang Diharapkan

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.

Pembersihan

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

Detail

Kategori
Thermochemistry
Tingkat Kesulitan
Intermediate (High School)
Durasi
40 menit
Perkiraan Biaya
$8,00
Langkah
6
Bahan
3

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Frequently Asked Questions

What is the objective of Kalorimetri Cangkir Kopi?
Tentukan entalpi penetralan HCl dan NaOH menggunakan kalorimeter cangkir polistirena.
How difficult is Kalorimetri Cangkir Kopi?
This experiment is rated as Intermediate (High School). It takes approximately 40 minutes to complete.
What safety precautions are needed for Kalorimetri Cangkir Kopi?
Key safety precautions include: HCl and NaOH are corrosive; Wear safety goggles; The mixture will get hot.
What materials are needed for Kalorimetri Cangkir Kopi?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Distilled water.
What results should I expect from Kalorimetri Cangkir Kopi?
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.