# physics

posted by .

When an immersion glass thermometer is used to measure the temperature of a liquid, the temperature reading will be affected by an error due to heat transfer between the liquid and the thermometer. Suppose you want to measure the temperature of 7 mL of water in a Pyrex glass vial thermally insulated from the environment. The empty vial has a mass of 5.0 g. The thermometer you use is made of Pyrex glass as well and has a mass of 18 g, of which 4.5 g is the mercury inside the thermometer. The thermometer is initially at room temperature (20.0°C). You place the thermometer in the water in the vial and, after a while, you read an equilibrium temperature of 29°C. What was the actual temperature of the water in the vial before the temperature was measured? The specific heat capacity of Pyrex glass around room temperature is 800 J/(kg K) and that of liquid mercury at room temperature is 140 J/(kg K).

• physics -

-Qout=Qin
---------
-(Qwater+Qvial)=Qthermometer+Qmercury
-(mwater*cwater*(Tfinal-Tinitial)+mvial*cvial*(Tfinal-Tinitial)) = mthermometer*cthermometer*(Tfinal-Tinitial)+mmercury*cmercury*(Tfinal-Tinitial)

Plug in the equilibrium temperature for Tfinal. Then plug in the Room temperature for Thermometer and Mercury Tinitial. Solve for Water and Vial Tinitial. Done.

Make sure to use the right C numbers if you change the masses to kg.

## Similar Questions

1. ### physics

A piece of glass has a temperature of 72.0 °C. Liquid that has a temperature of 37.0 °C is poured over the glass, completely covering it, and the temperature at equilibrium is 50.0 °C. The mass of the glass and the liquid is the …
2. ### Chemistry

Suppose that you had a mercury-in-glass thermometer and calibrated to measure temperatures from -10 degrees C to 110 degrees C and you wished to measure a temperature of approximately 115 degrees C accurately. How might you use your …
3. ### engineering

A thermometer is used to measure the temperature of a gas flow through a pipe. The gas temperature is read at 500°C and the duct temperature is measured to be 350°C. The thermometer is cylindrical with a diameter of 1 mm and an intrusion …
4. ### Physics

An ornamental thermometer, commonly known as a Galileo thermometer, contains a number of spheres of hollow colored glass, representing different temperatures, immersed in a column of ethanol. A particular sphere rises from the bottom …
5. ### physics

Ideally, when a thermometer is used to measure the temperature of an object, the temperature of the object itself should not change. However, if a significant amount of heat flows from the object to the thermometer, the temperature …
6. ### PHYSICS

Ideally, when a thermometer is used to measure the temperature of an object, the temperature of the object itself should not change. However, if a significant amount of heat flows from the object to the thermometer, the temperature …
7. ### physics

A piece of glass has a temperature of 76.0 °C. Liquid that has a temperature of 40.0 °C is poured over the glass, completely covering it, and the temperature at equilibrium is 54.0 °C. The mass of the glass and the liquid is the …
8. ### physics

Temperatures are often measured with electrical resistance thermometers. Suppose that the resistance of such a resistance thermometer is 177Ω when its temperature is 28.7 °C. The wire is then immersed in a liquid, and the resistance …
9. ### Chem

In a lab where a thermometer is used to measure temperature for a hot liquid it is possible as and error that the thermometer will cause the temperature of the liquid to cool slightly causing a observation error but how can this be …
10. ### Science - heat

1-By opening the door of a refrigerator ehich is inside a room, the temperature of the room : A) decreases B) increases C) remains unchanged D) first decreases and then increases******(my ans) 2- The thermometer used to measure very …

More Similar Questions

Post a New Question