Why Do Barometers Use Mercury?
Mercury is commonly used in barometers because its high density means the height of the column can be a reasonable size to measure atmospheric pressure. A barometer using water for instance would need to be 13.6 times taller than a mercury barometer to obtain the same pressure difference.
Why did barometers use mercury?
Complete answer: In the barometer mercury is used as the barometric liquid. … Mercury has high density. Because of this property when there is a change in pressure the change in height of the mercury in the barometer tube will be very reasonable.
Why don’t we use water instead of mercury in barometer?
Explain why water cannot be used in place of mercury in a barometer? The atmospheric pressure at sea level = 76cm of Hg = 1.013×105 Pascal. That is if water is used in barometer tube instead of mercury the length of the tube must be greater than 10.326 cm. … So we cannot replace mercury by water in the barometer.
Why is mercury preferred over water in a barometer?
Mercury is used in barometers and not water. This is because the high density of mercury gives a reasonable height of the column to measure atmospheric pressure. While a barometer using water for instance would need to be 13.6 times higher column length than a mercury barometer to obtain the same pressure difference.
Why is mercury used as a barometric liquid give three reasons?
(i) The density of mercury is greater than that of all the liquids so only 0.76m height of mercury column is needed to balance the normal atmospheric pressure. (ii) The mercury neither wets nor sticks to the glass tube therefore it gives the correct reading.
How does a mercury barometer work?
The barometer works by balancing the weight of mercury in the glass tube against the atmospheric pressure much like a set of scales. … If the weight of mercury is less than the atmospheric pressure the mercury level in the glass tube rises (high pressure).
Do barometers contain mercury?
What are the disadvantages of mercury barometer?
- It has a long glass tube with no protection to it. …
- It requires zero adjustment before taking the reading.
- The barometer must be kept vertical to get the correct reading.
- The container in which the glass tube is inverted is open from the top.
Who invented mercury barometer?
Evangelista Torricelli
The mercury barometer is the oldest type of barometer invented by the Italian physicist Evangelista Torricelli in 1643. Torricelli conducted his first barometric experiments using a tube of water.Jun 19 2014
What is mercury barometer?
A mercury barometer is a barometer with a column of mercury whose height varies according to the atmospheric (barometric) pressure. A barometer is an instrument for measuring atmospheric pressure which is used in forecasting the weather.
What does the sudden fall in mercury in a barometer indicate?
Sudden fall in Mercury level: It signifies that there has been a fast fall in atmospheric pressure over the region. This will pool air from the surrounding regions vigorously and there is a possibility of storm in that area.
Why is not water used as a barometric liquid Give two reasons?
Water is not a suitable barometric liquid because: (i) The vapour pressure of water is high so its vapours in the vacuum space will make the reading inaccurate. (ii) Water sticks with the glass tube and wets it so the reading becomes inaccurate.
What is the meaning Torr?
The torr (symbol: Torr) is a unit of pressure based on an absolute scale defined as exactly 1760 of a standard atmosphere (101325 Pa). Thus one torr is exactly 101325760 pascals (≈ 133.32 Pa). … It is often combined with the metric prefix milli to name one millitorr (mTorr) or 0.001 Torr.
What is mercury barometer and its uses?
In the mercury barometer atmospheric pressure balances a column of mercury the height of which can be precisely measured. To increase their accuracy mercury barometers are often corrected for ambient temperature and the local value of gravity.
How do you use a simple mercury barometer?
How do barometers work without mercury?
Are mercury barometers accurate?
Which barometer does not employ mercury?
What are the advantages and disadvantages of a mercury barometer?
- To measure the altitude of a place.
- To measure the air (atmospheric) pressure of a certain environment.
- To know weather forecasting.
- For the calibration of aneroid barometers.
- To measure the pressure in aircrafts.
- For analysis of surface water.
What is the difference between aneroid barometer and mercury barometer?
What are the advantages of simple barometer?
Aneroid barometer does not need a mercury column so it is compact. It is easier to handle. 2. It is easier to read as the measurements are calibrate minutely.
How does a barometer predict rain?
The basic rules of thumb are: If the barometer measures low air pressure the weather is bad if high pressure it is good. If pressure is falling then the weather will get worse if rising better. The faster it is falling or rising the faster and more the weather will change.
What do gradual increase in mercury level in barometer indicate?
Gradual rise in mercury level is equal to good weather conditions or sunny days. Thus no possibility of rain. Note:Remember that the glass tube is immersed in the mercury the air pressure in the atmosphere presses the surface of the mercury.
What is the principle of an aneroid barometer state its advantages over a mercury barometer?
The aneroid barometer is more durable and compact and much easier to read. The only particular advantage of a mercury barometer is that it’s a direct measurement — there’s no calibration involved. If you can measure the height of the column above the pool and you know the density of mercury you have the pressure.
What do the following indicate in a barometer regarding weather i gradual fall in the mercury level 2 sudden fall in mercury level 3 gradual rise in mercury level?
Gradual fall in mercury level =The weather is going to be bad like stormy weather or thundering clouds.
Why water Cannot be used in barometers?
water cannot be used as barometric liquid because it’s density is lower than Mercury . water’s density is 1000 gram per cubic meter. hence it requires a barometer whose height is around 11 meters.
What is a barometer suggest a reason why water is not a suitable barometric liquid?
Water is highly inconvenient to take a tube of height 10.4 m for a barometer. The vapor pressure of water is high so its vapors in the vacuum space will make the reading inaccurate.
What is barometric liquid?
Barometric Liquid ( Defined ) A barometer is an instrument used to measure atmospheric pressure and the liquid inside it used to measure the atmospheric pressure is barometric liquid. Barometer uses Mercury ( A highly Poisonous liquid metal) as it’s liquid.
Is torr same as mmHg?
One unit of gas pressure is the millimeter of mercury (mmHg). An equivalent unit to the mmHg is called the torr in honor of the inventor of the barometer Evangelista Torricelli. … Standard atmospheric pressure is called 1 atm of pressure and is equal to 760 mmHg and 101.3 kPa.
Is 1 atm exactly 760 mmHg?
1 atm = 101 325 Pascals = 760 mm Hg = 760 torr = 14.7 psi. The prefix “kilo” means “1 000” so one kilopascal = 1 000 Pa.
Which unit is bar?
pressure
The bar is a metric unit of pressure but not part of the International System of Units (SI). It is defined as exactly equal to 100 000 Pa (100 kPa) or slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar).
How does a mercury barometer measure pressure?
How does a mercury barometer move?
The best advice we can give is to just tilt the barometer slowly and gently to 45 degrees and let the top of the tube fill with mercury then transport the barometer at that angle. Be sure to wrap the barometer in a good stout plastic bag to contain any possible mercury spills and cushion it well.
What is the working of barometer?
How does a barometer work? Simply put a barometer acts like a balance that ‘balances’ the weight of the atmosphere (or air around you) against the weight of a mercury column. If the air pressure is high the mercury will rise. At low air pressure the mercury goes down.
The history of the barometer (and how it works) – Asaf Bar-Yosef
32 Mercury Barometer
Mercury Barometer
Why Mercury is used in Barometer not Water ?||Informative||competent Chemistry||abdulrehman