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Why is the entire mercury bulb of the thermometer must be below the level of the side arm in order to obtain an accurate reading of the distillation?
Wiki User
∙ 12y ago
The boiling point of the distillate is normally the temperature of the vapour. If the bulb of the thermometer is placed too high, above the sidearm leading to the condeser, the entire bulb will not be heated up by the vapour of the distillate, and the temperature will be too low. however, if the bulb of the thermometer is placed too low, too near to the surface of the boiling water, the thermometer will show a too-high reading.Thus, the bulb of the thermometer should be placed at the sidearm or just below the sidearm in order to obtain an accurate reading of the distillation.
Source: http://books.Google.com.sg/books?id=qHoWToUx1uYC&pg=PA86&lpg=PA86&dq=why+is+the+bulb+of+the+thermometer+placed+at+the+sidearm&source=bl&ots=JBLp_O9h3d&sig=cY86Ubsrci1WpGedNfoU9x8GovE&hl=en&ei=1yRPSoO1JISIsgP02K2XBw&sa=X&oi=book_result&ct=result&resnum=1
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoIt is important to place the thermometer bulb at the correct place because it measures the temperature of the vapors being produced not of the solution being distilled. The correct place is right at the base of the opening from the distillation head to the condenser.
Wiki User
∙ 13y agoHad you dip it in the solution, the thermometer would have measured the temperature of the direct heat from the flame. However, what we want is the temperature at which a substance boils. Hence, by positioning the thermometer near the sidearm of the distillation flask measures the temperature of the vapour which is also the boiling point of that substance.
Wiki User
∙ 13y agoIf it is a standard distillation, most of the Mercury in the thermometer is in the bulb, and this must be allowed to be in equilibrium with the vapour coming out of the still, and therefore completely below the point where the vapour pours into the condensor.
Stephen L. Escora
• The bulb part of the thermometer is positioned near the side arm of the Y-adaptor so that it monitors the temperature of the vapours. If it is positioned too high, it will be out of the path of the vapours and read lower than the true temperature.
Wiki User
∙ 12y agoto completely bathe the mercury bulb of the thermometer so you can get an accurate measurement
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Why do you have to shake the clinical thermometer after reading but do not have to shake the laboratory thermometer?
So that the mercury will return to its original position (becos there's a constriction that actually keeps the mercury in place after u remove it from your mouth)
Is Mercury a pure compound?
Mercury is an element that is also a liquid. It is in the Periodic Table and is #80.
Why was it important not to let the thermometer rest on the bottom of the breaker?
to get an accurate reading of the liquid inside the beaker, the thermometer should not rest on the bottom of the beaker.
Where would a good place be to place a room thermometer so that it will get an accurate reading?
There are several good places where a person can place a room thermometer so it will give an accurate reading. A person should place it in the middle of the room in the center of their home. Also, make sure it isn't near a window, door or heater, all which can affect the reading.
Why must you read the temperature without removing the thermometer from the solution?
The thermometer reading will change from reading the solution temperature.
Define vapor pressure thermometer?
A thermometer which utilizes a gas(vapor) to react to temperature changes for an accurate reading. (Instead of a hazardous material such as a mercury filled thermometer.)
Why the reading of thermometer is taken when the mercury stop expanding?
The mercury will expand and rise up the thermometer tube until it reaches the temperature of the air around it. When it stops expanding, it is the same temperature as the air, and therefore gives an accurate reading.
Why do you have to shake the clinical thermometer after reading but do not have to shake the laboratory thermometer?
So that the mercury will return to its original position (becos there's a constriction that actually keeps the mercury in place after u remove it from your mouth)
What is the advantage and disadvantage of using alcohol in thermometer?
u don't have to flick the thermometer to reset the temperature reading when you use an alcohol based thermometer (unlike a mercury thermometer where you have to flick and flick and flick flick flick that thermometer for the mercury to be reset so that you can make an accurate reading) a disadvantage is that the alcohol thermometer is slightly less acurate The biggest advantage is that alcohol is not nearly as toxic as mercury, so that if the thermometer breaks, you won't be poisoned.
Why is there a constriction in a clinical thermometer?
The constriction prevents the mercury from returning back to the bulb when the thermometer is removed from a particular body.
Do you get the accurate temperature reading from the forehead if it is wet?
If you are referring to using a surface thermometer, no.
Which type of thermometer give the least accurate reading of all?
disposable thermometers
Why is in water used in thermometers?
Well, Mercury can't freeze or evaporate at the temperature recorded on a standard thermometer. If water were used in a thermometer, we wouldn't be able to record any temperatures below its freezing point (0 degrees Celsius) or above its boiling point (100 degrees Celsius. Mercury has many unique properties. It is a liquid metal and as a metal it expands when heated. When the mercury is heated it rises in the thermometer. And markings on the glass indicate the temperature. Water does not do this. But now in this Digital World mercury has been loosing its importance just because everyone wants to use Digital Technology which provide fast and accurate reading and also safe in use, no doubt mercury provides an accurate reading of temperature but it is not fast and safe as compared to Digital Thermometer.
What effect does the use of an uncalibrated thermometer have on the boiling point of a liquid?
The thermometer's reading of the point the liquid boils may not be accurate.
Why water is not used in thermometer?
Well, Mercury can't freeze or evaporate at the temperature recorded on a standard thermometer. If water were used in a thermometer, we wouldn't be able to record any temperatures below its freezing point (0 degrees Celsius) or above its boiling point (100 degrees Celsius. Mercury has many unique properties. It is a liquid metal and as a metal it expands when heated. When the mercury is heated it rises in the thermometer. And markings on the glass indicate the temperature. Water does not do this. But now in this Digital World mercury has been loosing its importance just because everyone wants to use Digital Technology which provide fast and accurate reading and also safe in use, no doubt mercury provides an accurate reading of temperature but it is not fast and safe as compared to Digital Thermometer.
Why there is kink in clinical thermometer?
In a normal clinical thermometer, the mercury moves up and down the capillary tube as the temperature changes and thus if you removed it from contact with the patient the reading would steadily fall as it cooed. As you need a clinical thermometer to give you a reading of the patients temperature even after it has been removed from the patient, you need to stop the mercury shrinking back into the reservoir. The 'kink' breaks the connection between the mercury in the capillary tube and the reservoir so the reading given is accurate. On the other hand before it can be used again the mercury in the capillary tube has to be vigorously shaken back into the reservoir.On a point of interest, clinical thermometers are getting very rare because they have been phased out due to concerns regarding mercury poisoning should they break in use.
Is Mercury a pure compound?
Mercury is an element that is also a liquid. It is in the Periodic Table and is #80.
