A chemist wants to make 450. mL of a solution that is 0.500 M in concentration of Zn2+. Her available materials are 1.45 M ZnSO4 and 0.200 M ZnCl2. Unfortunately for the chemist, there is no deionized water available to dilute the solutions. Assuming that the solutions’ volumes are additive, how many mL of each solution are required to make the 450. mL of 0.500 M Zn2+solution? Which of the ions present has the lowest concentration in the final solution Volume of 1.45 M ZnSO4
Volume of 0.200 M ZnCl2
Ion with lowest concentration in final solution

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.