Write balanced equations for the following reactions (a) reaction between magnesium (mg) and nitrogen (n.) to form mg n, at high a temperature. (b) reaction between mgan, and water to form magnesium hydroxide and ammonia (nh) (c) decomposition of magnesium hydroxide when it is strongly heated. see step 22 of the procedure for the products formed in this reaction.] a sample of 0.756 moles of propane (ch) is completely burned in 1.95 moles of oxygen. the products are carbon dioxide and water. (a) write the balanced equation. (b) which is the limiting reactant? (show calculations) (c) how many moles of water are produced during this reaction? (show calculations) (d) which is the excess reactant? how much of the excess reactant remains unreacted?

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.