The composition of a compound is 6.27 g calcium and 1.46 g nitrogen. Calculate the empirical formula.

Ca₃N₂

Explanation:

The empirical formula is the simplest whole-number ratio between moles of each element present in a molecule.

Thus, we need to convert mass of each atom to moles and find the ratio between these as follows:

Moles N:

1.46g * (1mol / 14.0067g) = 0.104moles

Moles Ca:

6.27g * (1mol / 40.078g) = 0.156moles

The ratio between Moles N and moles of Ca is:

0.156moles / 0.104 moles = 1.5

That means there are 1.5 moles of Ca per mole of N. As empirical formula must be given in whole numbers:

There are 3 moles of Ca per 2 moles of N.

Empirical formula is:

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.