. A 60.0 g piece of Zn at 20.0 o C is dropped into 200.0 g of water at 100.0 o C. Determine the final temperature reached by the Zn and water, knowing that the specific heat capacity of Zn and water are 0.389 J/(g. o C) and 4.184 J/(g. o C), respectively.

97.8 C

Explanation:

Recall the equation for specific heat:

q = mcΔT

There are several things to know in order to answer this question:

1. Whatever heat energy one object gains is the same as the heat energy the other has lost (conservation of energy).

2. Since one substance loses heat and the other gains heat, you need to multiply one side by -1 to account for the opposite direction of heat transfer.

3. The final temperature of both substance will be the same (zeroth law of thermodynamics)

Below, the left side of the equation represents water and the right side represents zinc.

-1 x 200 x 4.184 x (T - 100) = 60 x 0.389 x (T - 20)

Solve this equation and you get T = 97.8.

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.