How many moles of nitrogen dioxide gas will be produced if 25.0 ml of 2M nitric acid react? Cu + HNO3 = Cu(NO3)2 + NO2 + H2O

0.025 moles of NO₂  will produced

Explanation:

Given data:

Moles of NO₂ formed = ?

Volume of HNO₃ = 25.0 mL

Molarity of HNO₃ = 2 M

Solution:

Chemical equation:

Cu + 4HNO₃   →        Cu(NO₃)₂ + 2NO₂ + 2H₂O

Number of moles of HNO₃:

Molarity = number of moles /  volume in L

2M = number of moles / 0.025 L

Number of moles = 2 M × 0.025 L

Number of moles = 0.05 mol

Now we will compare the moles of HNO₃  with NO₂  from balance chemical equation.

                                  HNO₃            :          NO₂

                                      4                :            2

                                 0.05               :         2/4×0.05 =0.025

0.025 moles of NO₂  will produced.

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.