Does warmer oil flow faster?
Keep the liquid and opening the same. Change the temperature, time a fixed amount flowing, and compare repeated readings.
How does oil temperature affect the time it takes 6 mL to flow through the same opening?
Viscosity means resistance to flow. Density means mass per unit volume; they are different properties. Many liquids flow more easily when warmer because their particles move past one another more readily. This test measures elapsed time, not an exact viscosity. The opening, amount of liquid above it, temperature and bubbles can all affect the time.
Review the related lesson →Science words you will use
A hypothesis is a possible explanation. A prediction is what you expect to observe. The independent variable is what you change or compare; the dependent variable is what you measure. Controlled variables stay the same in a fair test. Qualitative observations describe what you notice; quantitative observations use numbers and units.
Accuracy means closeness to a trusted value. Precision describes how closely repeated readings agree. Repeating a result does not prove it is accurate. A pattern between two quantities does not, by itself, show that one caused the other.
What good work includes
- Change temperature while keeping the liquid, opening and measured volume interval the same.
- Collect three real flow times near each of three temperatures and record actual temperatures.
- Use measurements and their variation to support a conclusion with one specific limitation.
Plan your investigation
Plan your investigation
Use your own words. You can return and change your ideas as you collect evidence.
Set up a controlled flow test
Clamp one 10 mL plastic syringe barrel vertically over a collecting cup. Remove the plunger and use no needle. Oil drains under gravity. Time the level falling from 8 mL to 2 mL: a fixed 6 mL interval. Your teacher must pilot the apparatus first and choose an opening that gives a measurable time without squeezing or pushing.
Sketch shown at the start mark; not to scale. Use the actual barrel markings. Start timing at 8 mL, not when you remove the cap.
Materials & safety
- One 10 mL plastic syringe barrel without plunger or needle, and a removable tip cap
- Stable clamp stand, collecting cup and spill tray
- One batch of teacher-approved vegetable oil
- Digital thermometer and stopwatch
- Teacher-prepared cool, room-temperature and warm water baths
- Safety goggles and spill-cleaning materials
Teacher supervision is required. Use plastic equipment with no needle and wear goggles. The teacher prepares water baths at or below 40°C. Students do not use kettles, hot plates or flames. Do not taste liquids. Keep bath water out of the oil. Clean spills immediately and collect used oil as your teacher directs; do not pour it down a drain.
Suggested procedure — adapt and record changes
- Write a prediction and plan a fair test. Have your teacher pilot the apparatus. If the oil flows too fast to time reliably or the opening clogs, adjust the apparatus before collecting data and record the change.
- Choose three approved temperatures, such as about 15°C, 25°C and 35°C. Prepare separate portions from the same oil batch in covered containers in the water baths. Wait until the oil temperature is steady.
- Keep the same syringe, opening, vertical position and 8-to-2 mL interval. Before every run, rinse the barrel with a little oil at the test temperature and let it drain. Keep water out of the barrel. Use the same person or method for timing.
- Measure the actual temperature of the oil portion immediately before transfer. Record it rather than copying the bath target. Remove the thermometer, cap the syringe tip and fill the barrel to 10 mL. Check for bubbles.
- Remove the cap without pushing on the oil. Start timing when the bottom of the oil surface passes 8 mL; stop at 2 mL. Read the marks at eye level. Record the elapsed time in seconds and anything unusual.
- Collect three readings near each chosen temperature using fresh portions of the same oil and the same preparation steps. Measure temperature before each run. Keep unusual readings and explain them; do not remove a value because it disagrees with your prediction.
- If time allows, return to room temperature for a final check. A changed time may show that the apparatus or method changed. Record and discuss the result.
- Graph time against actual temperature. Compare readings near each temperature and the spread of repeat times. Mean view only combines exactly matching group labels and temperatures; do not alter temperatures to force a mean. Explain what the evidence suggests and one limitation.
Your data and graph
Enter actual temperatures from 5°C to 40°C and positive times in seconds. No flow before your stopping time is not a zero-second result: describe it in your notebook and discuss it with your teacher.
The table keeps your exact readings. On a small screen, scroll inside the table or graph to see the rest. With a keyboard, focus it and use the arrow keys.
Add readings to enable data and graph downloads.
Explain your results and reflect
Think like a scientistExplain, question and reflect
A new question to explore
Try another teacher-approved vegetable oil as a separate group. Compare the two oils at the same temperature. Explain why flow time alone does not tell you which liquid is denser.
Your lab report
Preview your notes, measurements, calculations and graph. Choose Print / Save as PDF in the report, or download an HTML copy. Submit that PDF in Google Classroom using your teacher’s instructions. This website does not submit your work.
A backup is a JSON file for restoring this notebook. It is different from your finished report. Keep your own copy before clearing browser data or changing devices.