A student determines the copper(II) content of a solution by first precipitating it as copper(II) hydroxide, and then decomposing the hydroxide to copper(II) oxide by heating. How many grams of copper(II) oxide should the student obtain if his solution contains 40.0 mL of 0.462 M copper(II) nitrate?

1.44g of CuO

Explanation:

First we put down the balanced chemical reaction equations involved. Then we obtain the amount of Cu2+ present in the Cu(NO3) from the information provided. This same amount of Cu2+ is present in Cu(OH)2 which decomposes to give copper II oxide. From the balanced reaction equation, we obtain the mass of CuO obtained from this amount of Cu2+ as shown in the image attached.

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.