HS 1st year : Chemistry chapter 6 Equilibrium experiments

 

Experiment Title:

Study of Chemical Equilibrium – Effect of Concentration on the Position of Equilibrium

Objective:

To observe the effect of changing concentration on the position of equilibrium in a reversible reaction.

Materials Required:

• Iron(III) chloride solution (FeCl₃)

• Potassium thiocyanate solution (KSCN)

• Distilled water

• Test tubes

• Dropper

• Beaker

• Glass rod

Chemical Reaction:

$\text{Fe}^{3+}(aq) + \text{SCN}^-(aq) \rightleftharpoons \text{FeSCN}^{2+}(aq)$
This reaction shows a reddish-brown complex formation, which is reversible.

Procedure:

1. Preparation of Equilibrium Mixture:

   • Take about 5 mL of 0.002 M FeCl₃ solution in a test tube.

   • Add 5 mL of 0.002 M KSCN solution.

   • Mix well and observe the reddish-brown colour of FeSCN²⁺ complex indicating equilibrium.

2. Effect of Adding Reactant (KSCN):

   • Take a small portion of the equilibrium mixture in another test tube.

   • Add a few drops of KSCN solution.

   • Observe the intensification of the reddish-brown colour (due to shift in equilibrium to the right).

3. Effect of Adding Reactant (FeCl₃):

   • Take another portion of the original equilibrium mixture.

   • Add a few drops of FeCl₃ solution.

   • Observe the increase in colour intensity again (shift to the right).

4. Effect of Dilution:

   • Take a third portion of the equilibrium mixture.

   • Add distilled water.

   • Observe the fading of the colour indicating a shift in equilibrium (can be interpreted depending on ion concentration changes).

Observation:

• Addition of either Fe³⁺ or SCN⁻ ions deepens the colour of the complex.

• This confirms that equilibrium shifts to the right (product side) when reactant concentration increases (as per Le Chatelier’s Principle).

Conclusion:

The position of chemical equilibrium is influenced by the concentration of reactants. Increasing the concentration of reactants shifts the equilibrium towards the formation of more product.

HS 1st year : Chemistry chapter 5 Thermodynamics experiments

 

Experiment 1: Determination of the Mechanical Equivalent of Heat (J) using Joule’s Calorimeter

Apparatus Required:
Joule’s calorimeter, battery, ammeter, voltmeter, stopwatch, rheostat, key, and connecting wires.

Procedure:

1. Arrange the Joule’s calorimeter with stirrer and heating coil inside it.

2. Measure the mass of water in the calorimeter.

3. Note the initial temperature of the water.

4. Complete the circuit using the battery, ammeter, voltmeter, and key.

5. Close the key and start the stopwatch simultaneously.

6. Keep the current flowing for a known time interval.

7. Note the final temperature of the water.

8. Use the known values of voltage (V), current (I), and time (t) to calculate the heat produced:

   $$H = VIt \, \text{joules}$$

9. Compare the calculated heat with the heat gained by the water:

   $$H' = mc\Delta T$$

10. The mechanical equivalent of heat $J = \frac{H}{H'}$

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Experiment 2: Determination of Specific Heat of a Liquid by the Method of Mixtures

Apparatus Required:
Calorimeter, thermometer, stirrer, water, and the liquid under test.

Procedure:

1. Measure and record the mass of the calorimeter and water.

2. Note the initial temperature of water.

3. Heat the liquid to a known temperature.

4. Pour the hot liquid into the calorimeter containing water.

5. Stir gently and note the final temperature.

6. Use the principle of calorimetry:

   $$\text{Heat lost by liquid} = \text{Heat gained by water + calorimeter}$$

7. Calculate the specific heat of the liquid using the formula.

HS1 Physics GRAVITATION Chapter 7: Experiments

 Title: Experiment to Measure Acceleration Due to Gravity (g) Using a Simple Pendulum

Objective: To determine the acceleration due to gravity (g) using a simple pendulum.

Materials Required:

1. A rigid support with a hook

2. A long, inextensible thread (approximately 1-2 meters)

3. A small, heavy bob (metal sphere)

4. Stopwatch

5. Meter scale

6. Protractor

Theory: The time period (T) of a simple pendulum is given by the formula:

where:

• = Time period of the pendulum

• = Length of the pendulum

• = Acceleration due to gravity

From this formula, can be calculated using:

Procedure:

1. Set up the simple pendulum by suspending the bob with the thread from the rigid support.

2. Measure the length of the pendulum (L) from the point of suspension to the center of the bob using the meter scale.

3. Displace the pendulum slightly (small angle, less than 10°) and release it without any push.

4. Use the stopwatch to measure the time for 20 complete oscillations and record it.

5. Calculate the time period (T) by dividing the recorded time by 20.

6. Repeat the experiment 3 times for accuracy and take the average value of T.

7. Substitute the values of L and T in the formula to calculate g.

Observations:

• Length of the pendulum (L) = ______ cm

• Time for 20 oscillations (Trial 1) = ______ s

• Time for 20 oscillations (Trial 2) = ______ s

• Time for 20 oscillations (Trial 3) = ______ s

• Average time for 20 oscillations = ______ s

• Time period (T) = Average time / 20 = ______ s

Calculation: Substitute the average value of T and the value of L in the formula:

Result: The calculated value of acceleration due to gravity (g) is ______ m/s².

Precautions:

1. Ensure the amplitude of oscillations is small (less than 10°).

2. The thread should be inextensible and should not have any knots.

3. The bob should be heavy and spherical for smooth oscillations.

4. The pendulum should not be affected by air currents.

HS1 Physics LAWS OF MOTION Chapter 4: Experiments

 

Experiment Process for Demonstrating Laws of Motion

Aim:

To demonstrate Newton's Laws of Motion through simple experiments.

Materials Required:

• A smooth wooden surface

• A small wooden block

• Spring balance

• String

• Pulley

• Weights (different masses)

• Stopwatch

• Graph paper

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Procedure:

1. Demonstrating Newton's First Law (Law of Inertia):

1. Place the wooden block on the smooth surface.

2. Gently push the block. Observe that it moves but stops after some time due to friction.

3. Now, remove friction by making the surface even smoother (use a glass surface).

4. Observe that the block moves farther, showing that an object continues in its state of rest or uniform motion unless acted upon by an external force.

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2. Demonstrating Newton's Second Law (F=ma):

1. Attach a string to the wooden block and pass it over the pulley.

2. Attach a weight to the other end of the string.

3. Measure the acceleration of the block using the stopwatch as it moves.

4. Repeat with different weights and record the acceleration in each case.

5. Plot a graph of force (weight) against acceleration to show that force is directly proportional to acceleration (F = ma).

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3. Demonstrating Newton's Third Law (Action and Reaction):

1. Place two identical blocks on a smooth surface, one of which has a spring-loaded surface.

2. Push one block towards the other.

3. Observe that both blocks move in opposite directions, showing that for every action, there is an equal and opposite reaction.

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Observations:

Record your observations for each of the three experiments in a tabular format.

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Conclusion:

• The experiment demonstrates all three laws of motion effectively:

  • The first law (Inertia) is shown by the object's resistance to changes in motion.

  • The second law (F=ma) is verified by the direct proportionality of force and acceleration.

  • The third law (Action-Reaction) is shown by the interaction between two blocks.

HS1 Physics MOTION IN A PLANE Chapter 3: Experiments

 

Experiment: Study of Motion in a Plane (Projectile Motion)

Objective:

To study the motion of a projectile and verify the independence of horizontal and vertical motions.

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Apparatus Required:

• Projectile launcher or a spring-loaded gun

• Ball (small metal or plastic)

• Carbon paper

• Measuring scale or tape

• Stopwatch (if needed)

• Protractor

• Plumb line

• White chart paper

• Stand with clamp

• Ticker timer (for motion tracking, optional)

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Theory:

Projectile motion is a form of motion in which an object moves in a curved path under the action of gravity. The horizontal and vertical motions are independent of each other, with:

• Horizontal motion at constant velocity.

• Vertical motion with constant acceleration due to gravity.

Equations of motion used:

• Horizontal: $x = u_x t$

• Vertical: $y = u_y t + \frac{1}{2} g t^2$

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Procedure:

1. Setup the apparatus on a level table. Place the launcher at the edge and align it horizontally.

2. Mount the chart paper on the floor below the edge of the table.

3. Place carbon paper on top of the chart to mark the point of landing.

4. Launch the projectile horizontally from a known height.

5. Measure the horizontal distance (range) from the base of the table to the point of impact.

6. Calculate the time of flight using the vertical height $h$ from which the projectile is launched:

   $$t = \sqrt{\frac{2h}{g}}$$

7. Calculate the horizontal velocity:

   $$u_x = \frac{Range}{Time}$$

8. Repeat the experiment 3–5 times to ensure accuracy.

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Observations:

Record height, range, time of flight, and calculate the theoretical and experimental velocities.

Trial	Height (h)	Range (x)	Time of Flight (t)	Velocity (u_x)
1
2
...

Result:

• The calculated values verify the independence of horizontal and vertical motions.

• Projectile follows a parabolic path, consistent with theoretical predictions.

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Precautions:

• Ensure the launcher is horizontal.

• Measure the height accurately using a plumb line.

• Use a flat and level surface for the experiment.

• Avoid air drafts.

HS2 Physics Chapter 8 ELECTROMAGNETIC WAVES : Experiments

 

Experiment Title:

Demonstration of Displacement Current and Verification of Electromagnetic Wave Properties

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Aim:

1. To demonstrate the existence of displacement current using a charging capacitor.

2. To verify that the displacement current is equal to the conduction current.

3. To observe the nature of electromagnetic (EM) wave propagation (E ⊥ B ⊥ direction of propagation).

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Apparatus Required:

• Parallel Plate Capacitor

• DC Power Supply

• Switch

• Ammeter (for conduction current)

• Magnetic Field Sensor or small compass

• Connecting Wires

• CRO (optional for waveform observation)

• Function Generator (for AC EM wave demonstration)

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Theory:

• According to Maxwell, a time-varying electric field produces a displacement current which acts as a source of magnetic field similar to conduction current.

• Displacement current is given by:

  $$i_d = \varepsilon_0 \frac{d\Phi_E}{dt}$$

• In a charging capacitor, between the plates, there is no conduction current, yet magnetic field exists — evidence of displacement current.

• EM waves are transverse in nature, with electric field (E) and magnetic field (B) perpendicular to each other and the direction of wave propagation.

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Procedure:

Part A: Demonstration of Displacement Current

1. Connect the capacitor in series with a DC power supply, a switch, and an ammeter.

2. Close the switch to start charging the capacitor.

3. Observe the current in the ammeter — this is the conduction current in the wire.

4. Place a magnetic field sensor or a compass between the capacitor plates (ensure plates are partially open to access).

5. Detect magnetic field — this confirms the presence of a magnetic field inside the capacitor, despite no physical current flow.

6. Conclude that a displacement current exists inside the capacitor, equal in magnitude to the conduction current.

Part B: Verification of EM Wave Orientation (Optional with AC Source)

1. Connect a function generator to a dipole antenna (or capacitor).

2. Observe the oscillating electric field using an electric field probe.

3. Use a magnetic field sensor orthogonal to the electric field direction to detect B.

4. Verify that E ⊥ B ⊥ direction of propagation as expected from the EM wave model.

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Observations:

• Charging current observed on ammeter: ________ A

• Magnetic field detected between plates: Yes/No

• Orientation of E and B fields in AC demonstration: Confirmed / Not confirmed

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Calculations:

Calculate the displacement current:

$$i_d = \varepsilon_0 \frac{dE}{dt} \cdot A$$

Compare with the measured conduction current $i_c$.

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Result:

• The displacement current exists and equals the conduction current during capacitor charging.

• Magnetic field inside the capacitor confirms Maxwell’s prediction.

• Orientation of EM wave components follows the expected transverse nature.

HS2 Physics Chapter 7 ALTERNATING CURRENT: Experiments

 

Experiment Title: Alternating Current

Aim:

To study the characteristics of alternating current and verify the relationship between root mean square (rms) value and peak value of AC voltage.

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Apparatus Required:

• Step-down Transformer

• AC Voltmeter

• DC Voltmeter

• Milliammeter

• Resistor (Load)

• Diode (for rectification)

• CRO (Cathode Ray Oscilloscope)

• Connecting Wires

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Theory:

Alternating current (AC) varies sinusoidally with time and is given by:
$I(t) = I_0 \sin(\omega t)$

Where:

• $I_0$ is the peak current,

• $\omega = 2\pi f$ is the angular frequency.

The root mean square (rms) value of AC is:
$I_{rms} = \frac{I_0}{\sqrt{2}}$

For voltage:
$V_{rms} = \frac{V_0}{\sqrt{2}}$

This experiment also explores rectification (conversion of AC to DC) and filtering.

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Procedure:

Part A: Observation of AC Waveform

1. Connect the step-down transformer to the AC mains.

2. Connect the secondary coil of the transformer to the CRO.

3. Switch on the transformer and observe the waveform on the CRO screen.

4. Measure the peak voltage $V_0$ using the vertical scale of the CRO.

5. Calculate the rms voltage using:
   $V_{rms} = \frac{V_0}{\sqrt{2}}$

Part B: Verification using AC Voltmeter

6. Connect an AC voltmeter across the transformer secondary.

7. Record the reading of the voltmeter (which gives $V_{rms}$).

8. Compare this value with the calculated $V_{rms}$ from the CRO observation.

Part C: Rectification and Filtering

9. Connect a diode in series with a resistor to form a half-wave rectifier circuit.

10. Connect this circuit to the transformer output.

11. Use a DC voltmeter across the resistor to measure the rectified DC voltage.

12. To observe the filtered output, connect a capacitor in parallel with the resistor and note the change in output waveform on the CRO.

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Observations:

Record values of:

• Peak Voltage from CRO

• RMS Voltage (Calculated and Measured)

• DC Output Voltage (Rectified)

• Waveform shape before and after filtering

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Calculations:

Compute:

• RMS voltage from peak voltage

• % error between measured and calculated values

• DC output with and without filtering

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Result:

• The rms value of AC is verified to be $\frac{V_0}{\sqrt{2}}$

• The AC waveform, rectified output, and filtered output were successfully observed and recorded

HS2 Physics Chapter 6 ELECTROMAGNETIC INDUCTION : Experiments

 

Experiment: Demonstration of Electromagnetic Induction

Objective:

To demonstrate the phenomenon of electromagnetic induction and verify Faraday’s laws.

Apparatus Required:

• A solenoid or coil of wire

• A galvanometer

• A strong bar magnet

• Connecting wires

• Stand and clamps

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Procedure:

1. Setup:

   • Connect the coil to the galvanometer using connecting wires.

   • Fix the coil vertically using a stand.

   • Ensure the galvanometer is zeroed and sensitive enough to detect small currents.

2. Demonstration Steps:
   a) Moving Magnet into the Coil:

   • Quickly insert the north pole of the bar magnet into the coil.

   • Observe the galvanometer. It should show a deflection, indicating an induced current.

   b) Stationary Magnet:

   • Hold the magnet stationary inside the coil.

   • The galvanometer shows no deflection, indicating no current is induced when there is no change in magnetic flux.

   c) Withdrawing the Magnet:

   • Pull the magnet out of the coil.

   • The galvanometer deflects in the opposite direction, showing a reverse current is induced.

   d) Changing the Speed:

   • Insert and remove the magnet more quickly.

   • The deflection increases, indicating a larger induced EMF with a faster rate of change of magnetic flux.

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Observations:

• A current is induced in the coil only when there is a relative motion between the magnet and the coil.

• The direction of the current changes with the direction of motion.

• Faster motion causes greater deflection, confirming that the induced EMF is proportional to the rate of change of magnetic flux.

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Conclusion:

This experiment verifies Faraday’s laws of electromagnetic induction:

• An EMF is induced when the magnetic flux linked with a circuit changes.

• The magnitude of the induced EMF is proportional to the rate of change of flux.

• The direction of induced EMF opposes the cause producing it (Lenz’s law).