Imagine that you are in chemistry lab and need to make 1.00 l of a solution with a ph of 2.60. you have in front of you 100 ml of 7.00×10−2 m hcl, 100 ml of 5.00×10−2 m naoh, and plenty of distilled water. you start to add hcl to a beaker of water when someone asks you a question. when you return to your dilution, you accidentally grab the wrong cylinder and add some naoh. once you realize your error, you assess the situation. you have 80.0 ml of hcl and 87.0 ml of naoh left in their original containers. assuming the final solution will be diluted to 1.00 l , how much more hcl should you add to achieve the desired ph?

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.