Why alcohol is used in thermometer?
Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C, while mercury freezes at -38 degrees C. Thermometers rely upon thermal expansion of the liquid in a bulb at the base of a thin glass tube.
How do alcohol thermometers work?
Alcohol thermometers work by enclosing a narrow capillary attached to a bulb of reserve fluid. As the temperature heats up, the alcohol expands, rising up the capillary. As the temperature goes down, the fluid contracts, dropping down the capillary.
Why is alcohol used in the bulb of the thermometer to replace mercury?
Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. If it freezes it won’t move in the tube, so a liquid must be used that has a freezing point that’s lower than the temperature it’s measuring.
Can alcohol be used in thermometer?
alcohol is not used in thermometer. Mercury is used in it.
Why can’t you take your temperature with your hand?
The lower (closer to sea level) in the atmosphere you go, the greater the atmospheric pressure. IF you feel feverish, why can’t you take your own temperature with your hand? … Because mecury is denser it can handle more atmospheric pressure.
Can a smartphone be used as a thermometer?
With the right app, your Android smartphone or tablet can function as a thermometer using your device’s built-in temperature sensor. However, even if your mobile device is not equipped with a temperature sensor, there is still a way to get a decent temperature reading for the surrounding air.
How accurate are alcohol thermometers?
Alcohol thermometers are also inexpensive and durable. They are typically not as accurate as mercury thermometers because of the alcohol’s susceptibility to evaporation, polymerization potential and capillary separation. Their primary advantage is safety to humans and the environment.
Which has lower freezing point mercury or alcohol?
The freezing point of alcohol is about -170 F, and mercury -37.9 F. There is a technical reason for using mercury in clinical thermometers. Mercury has a greater coefficient of thermal expansion than alcohol.
Why is alcohol not used in thermometer?
Alcohol is not used in a clinical thermometer. It cannot measure the high temperatures because of its low boiling point.
How do you shake down an alcohol thermometer?
Grasp the Stem End Securely. Grasp the end of the thermometer that is opposite the bulb end with your fingers and thumb. The stem ends in a knob (usually colored either blue or red) that helps you to hold onto the thermometer during the shaking down process.
What liquid is used in thermometer and why?
Mercury is the only one in liquid state at room temperature. It’s used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures.