Charles Law Apparatus (Combined)
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Product Code : EL-POM-10373
Quick answer: The Charles law apparatus (combined), also called Jolly's apparatus, is used to study how the pressure of a fixed mass of air changes with temperature when its volume is held constant. A Jolly's air bulb is joined by rubber tubing to a mercury reservoir on a sliding bracket, read against a 0-100 cm scale. Lab Exports manufactures it in Delhi for colleges and universities.
Specifications
| Item | Specification |
|---|---|
| Also known as | Jolly's apparatus |
| Air bulb | Jolly's air bulb, connected by flexible rubber tubing |
| Mercury reservoir | Glass reservoir tube on a sliding bracket, movable along a vertical support rod |
| Stand | Polished wooden stand on a heavy cast metal base with levelling screw |
| Scale | Metre rule, 0-100 cm x 1 mm, readable in both directions |
| Mercury | Not included |
Mercury is not supplied; it should be handled over a spill tray and stored under the laboratory's own rules for mercury.
How the Jolly's apparatus experiment is done
The air bulb holds a fixed mass of dry air. When the bulb is warmed in a water bath the air tries to expand, so the mercury reservoir is raised on its sliding bracket until the mercury on the bulb side returns to its starting level and the volume of air stays the same. The difference between the two mercury levels, read on the metre rule and added to atmospheric pressure, gives the pressure of the gas at each temperature.
Plotted against temperature, the pressure rises in a straight line, and extended backwards the line meets zero pressure near -273 deg C. This is the pressure law, p/T = constant at constant volume, which is taught alongside Charles's law (V/T = constant at constant pressure) and leads to absolute zero and the Kelvin scale.
- Level the base with the levelling screw so that the metre rule stands vertical.
- With the bulb in a water bath at room temperature, set the reservoir so the mercury on the bulb side stands at a chosen reference level; record both levels and the temperature.
- Heat the water bath in steps, stirring, and at each temperature raise the reservoir to bring the mercury back to the reference level.
- Record the difference in mercury levels at each step and add the atmospheric pressure read from a barometer.
- Plot pressure against temperature and extend the line to find where the pressure would fall to zero.
Key features
- Jolly's air bulb that holds a fixed mass of air at constant volume
- Mercury reservoir on a sliding bracket, movable along the vertical support rod
- Metre rule 0-100 cm with 1 mm divisions, readable in both directions
- Polished wooden stand on a heavy cast metal base
- Levelling screw to set the scale truly vertical
Documentation and supply
Installation instructions and a manual are supplied with the apparatus. Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the Charles law apparatus (Jolly's type) at its works in Laxmi Nagar, Delhi, and supplies it to colleges and universities in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.
Related Properties of Matter products
- Expansion of Liquid Apparatus (EL-POM-10372)
- Charles Law Apparatus, Basic (EL-POM-10374)
- Liquid Level Apparatus (EL-POM-10371)
- Boyles Law Apparatus, Advanced with Oil (EL-POM-10375)
- Pascal Law Apparatus, Weinholds Type (EL-POM-10370)
- Bourdon Gauge (EL-POM-10376)
The full range is in the Properties of Matter section of the Physics Lab range.
Frequently asked questions
What does Jolly's apparatus measure?
It measures how the pressure of a fixed mass of air changes with temperature at constant volume, from the difference in mercury levels read on the scale.
Is mercury supplied with the apparatus?
No. The apparatus is supplied without mercury, which must be obtained, handled and stored under the laboratory's own safety rules.
What is the scale range?
The metre rule reads 0-100 cm in 1 mm divisions and can be read in both directions.
What is the price of the Charles law apparatus (Jolly's type)?
Prices are not published on the website. Add the Charles law apparatus (Jolly's type) to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-POM-10373 and the quantity, to receive a quotation.
Does Lab Exports manufacture the Charles law apparatus (Jolly's type)?
Yes. Lab Exports manufactures the Charles law apparatus (Jolly's type) at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-POM-10373.
Request a quote
Email [email protected] with the house code EL-POM-10373 and the quantity, or add the Charles law apparatus (Jolly's type) to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.
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