Identifying the Specific Heat Capacity of Vegetable Oil

Interactive chemistry logbook: read thermometers · record data · plot graph · extrapolate · calculate

Practical setup

Aim: determine the specific heat capacity of vegetable oil by comparing its temperature change with water heated on the same hotplate.


Example hypothesis: Vegetable oil will have a lower specific heat capacity than water. Therefore, when equal masses are heated under similar conditions, vegetable oil should have a larger temperature increase than water.

Logbook score

0 XP

Earn XP for accurate readings, graph plotting, extrapolation, calculations and MC questions. Hints reduce XP slightly.

Draft

Hypothesis

Logbook checklist

• Start the experiment to generate a new data set.
• Read both thermometers as the experiment runs.
• Fill in the table while the slider or auto-run changes the time.
• After the experiment ends, check your thermometer accuracy.
• Plot both graphs, extrapolate the cooling line, then complete the calculations.

Virtual laboratory and results table

Current time: 0 s Phase: Ready

Water

—

Vegetable oil

—
🔥🔥🔥
Time slider 0 s

Start the experiment from the setup page. Use the slider or smooth auto-run to move through the practical.

Zoomed water thermometer

Read the scale carefully between 20 and 90 °C.

Zoomed oil thermometer

Read the scale carefully between 20 and 90 °C.
Result entry
Record each temperature reading as the experiment runs. Check your readings after the experiment is complete.

Waiting for completion

Plot your own graph

Choose a substance, then tap/click the graph to place points. Use Delete to switch into eraser mode and remove individual points without clearing the rest.

Selected: water

Water Vegetable oil Revealed answer

Correct graph shown. The dotted lines and open circles are the correct water and oil data points. Your plotted points remain visible so you can compare them.
Recorded results

Extrapolate from your plotted graph

Use your cooling data and extend each best-fit line back to 0 s. The dashed vertical line marks when the beakers were removed from the hotplate. The temperature where each line crosses 0 s is the extrapolated final temperature for that liquid.

Selected: water line

Your water points Your oil points Revealed best-fit lines

Solution: The green dashed best-fit lines run through the cooling data and are extended backwards across the original graph to the y-axis at 0 s. Their y-intercepts are the extrapolated final water and oil temperatures.

Why extrapolate?

Once a beaker is removed from the hotplate, it begins losing energy to its surroundings. Keep the original time scale, draw a best-fit line through the cooling data, and extend it backwards to the original y-axis at 0 s.

Stepped calculations

Use your initial and corrected final temperatures. Complete and check each calculation in order.

Step 1: Calculate ΔT for water

ΔT(water) = T(final, corrected) − T(initial)
—°C

Step 2: Calculate q for water

q = m × c × ΔT, using c(water) = 4.18 J g⁻¹ °C⁻¹
—J

Step 3: Calculate ΔT for oil

Use the initial oil temperature and the extrapolated oil temperature from the y-axis intercept.
—°C

Step 4: Calculate c for oil

Assume q(oil) = q(water), then c(oil) = q ÷ (m × ΔT)
—J g⁻¹ °C⁻¹

Formula bank

• q = m × c × ΔT
• c(water) = 4.18 J g⁻¹ °C⁻¹
• c(oil) = q ÷ (m × ΔT)

Multiple choice analysis questions

Complete your logbook


Sample conclusion: Vegetable oil had a lower specific heat capacity than water because its temperature increased more when both liquids were heated under similar conditions. Extrapolating the cooling data improved the estimated final temperature and therefore improved the calculation of energy supplied. Experimental uncertainty remains because heat was lost to the surroundings and the two beakers may not have received exactly the same energy.

Reflection questions

• Which liquid had the larger temperature increase?
• How did extrapolation improve the result?
• What sources of error still remain?