कॉफी कप ऊष्मामिति

सरल ऊष्मामापी का उपयोग करके उदासीनीकरण की एन्थैल्पी मापना

Thermochemistry Intermediate (High School) 40 मिनट ~$8.00

उद्देश्य

पॉलीस्टायरीन कप ऊष्मामापी का उपयोग करके HCl और NaOH के उदासीनीकरण की एन्थैल्पी निर्धारित करें।

पृष्ठभूमि

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.

सुरक्षा चेतावनियाँ

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

आवश्यक PPE

goggles gloves lab_coat

सामग्री

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

उपकरण

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

प्रक्रिया

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 मिनट HCl is corrosive
2

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

2 मिनट NaOH is corrosive
3

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

1 मिनट Exothermic reaction
4

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

5 मिनट
5

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

5 मिनट
6

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

8 मिनट

अपेक्षित परिणाम

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.

सफाई

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

विवरण

श्रेणी
Thermochemistry
कठिनाई
Intermediate (High School)
अवधि
40 मिनट
अनुमानित लागत
$8.00
चरण
6
सामग्री
3

अधिक प्रयोग

ऊष्माशोषी अभिक्रिया प्रदर्शन 20 min कोल्ड पैक रसायन 20 min धातुओं की विशिष्ट ऊष्मा क्षमता 40 min बम ऊष्मामिति सिमुलेशन 45 min बर्फ की संलयन एन्थैल्पी 25 min मैग्नीशियम के दहन की गर्मी 50 min विघटन हमेशा ऊष्माक्षेपी नहीं होता 25 min सोडियम एसीटेट का ऊष्माक्षेपी क्रिस्टलीकरण 30 min हेस के नियम का सत्यापन 60 min

Frequently Asked Questions

What is the objective of कॉफी कप ऊष्मामिति?
पॉलीस्टायरीन कप ऊष्मामापी का उपयोग करके HCl और NaOH के उदासीनीकरण की एन्थैल्पी निर्धारित करें।
How difficult is कॉफी कप ऊष्मामिति?
This experiment is rated as Intermediate (High School). It takes approximately 40 minutes to complete.
What safety precautions are needed for कॉफी कप ऊष्मामिति?
Key safety precautions include: HCl and NaOH are corrosive; Wear safety goggles; The mixture will get hot.
What materials are needed for कॉफी कप ऊष्मामिति?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Distilled water.
What results should I expect from कॉफी कप ऊष्मामिति?
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.