Why is mercury and alcohol used in thermometers instead of water?

Why is mercury and alcohol used in thermometers instead of water?

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.

Why are thermometers filled with alcohol and not water?

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.

Why do you think alcohol is used instead of water?

As alcohol evaporates at a much faster rate compared with water due to its lower boiling temperature (82 compared to 100 degrees C), it is able to carry away more heat from the skin. This means for a given amount of time much more alcohol evaporates than water.

What happens when water is changed from a liquid to a gas?

Evaporation happens when a liquid turns into a gas. When liquid water reaches a low enough temperature, it freezes and becomes a solid—ice. When solid water is exposed to enough heat, it will melt and return to a liquid. As that liquid water is further heated, it evaporates and becomes a gas—water vapor.

What is the difference between water and alcohol?

The difference in polarity between water and alcohol can also explain another property of these liquids. Since alcohol is less polar than water, alcohol evaporates faster than water and boils at a lower temperature.

What is the difference between alcohol and mercury?

Main Difference – Alcohol vs Mercury Thermometers A thermometer is a device that is used to measure the temperature. The main difference between alcohol and mercury thermometer is that the bulb of mercury thermometer is filled with mercury whereas the bulb of alcohol thermometer is filled with an alcohol.

What is it called when water changes state from a gas to a liquid?

Condensation is when a gas becomes a liquid. It happens when a gas, like water vapor, cools down. Photo from: Wikimedia Commons. Evaporation and condensation are two processes through which matter changes from one state to another.

Why is mercury used instead of water in a thermometer?

A mercury thermometer is used to measure temperature. Why do people use alcohol in thermometers instead of water? Most often thermometers use mercury, but alcohol could be used as well since it has a very low freezing point (-114°C).

Why do people use alcohol in thermometers instead of water?

Because it has a high boiling point so that it won’t evaporate when it gets to a really high temperatureActually, the most common alcohol used in thermometers is ethanol which has a fairly low boiling point, 78ºC, compared with 100ºC for water.

What’s the freezing point of water in a thermometer?

Freezing point of water is 0 degree Celsius and the boiling point of water is 100 degree Celsius. So if we use water in the thermometer, then we won’t be able to measure the temperature lower than 0 degree celsius, as water freezes at these temperatures.

Why do you have to wash your thermometer before using it?

#1 Wash the thermometer before using it. Washing of the clinical thermometer is very necessary because it is used for different patients in clinics or hospitals. In order to prevent the transmission of bacteria or any other infections, the clinical thermometer should be washed before its use.