The balanced equation for the reaction of nitrogen gas and fluorine gas is

N2(g) + 3 F2(g) → 2 NF3(g)

What is the limiting reactant if 25 N2 molecules are allowed to react with 75 F2 molecules?

a. N2
b. F2
c. NF3
d. There is no limiting reactant: the reactants are present in stoichiometrically equivalent amounts
e. More information is needed to solve this problem

We don't have a limiting reactant.

The reactants are present in stoichiometrically equivalent amounts.

Option D is correct

Explanation:

Step 1: Data given

Molecules N2 = 25 molecules

Molecules F2 = 75 molecules

Number of Avogadro = 6.02 * 10^23 / moles

Step 2: Calculate moles N2

Moles N2 = molecules N2 / number of Avogadro

Moles N2 = 25 / 6.02 * 10^23

Moles N2 = 4.15 * 10^-23 moles

Step 3: Calculate moles F2

Moles F2 = 75 molecules / 6.02 * 10^23

Moles F2 = 1.25 *10^-22 moles

Step 4: Calculate limiting reactant

For 1 mol N2 we need 3 moles F2 to produce 2 moles NF3

For 4.15 * 10^-23 moles N2 we need 1.25 * 10^-22 moles F2

OR  

For 25 molecules N2 we need 75 molecules F2

Both reactants will completely react.

This means we don't have a limiting reactant.

The reactants are present in stoichiometrically equivalent amounts.

Option D is correct

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.

that's what i got you can count the number of atoms