No matter how many miles of helium is mixed with any number of moles of hydrogen there wont formation of any new compounds or molecules. Because helium is a noble gas. Which means it is in the most stable state possible. Hence you would still end up with two moles of helium and n moles of hydrogen.

Dear Aspirant,

Thermodynamics is a very important chapter and you will find a lot of questions from this topic in your school exams and also in various competitive exams like JEE, etc.

Here are some topics you should prepare for:

1. All Laws of thermodynamics
2. Cp-Cv=R
3. Basics of Carnot Engine
4. Isothermal,Isobaric,Isochoric and Adiabatic process
5. Change in Enthalpy and Work done.
6. Refrigerator.

Hope this helps. Thank you.

N2(g) + 3H2(g) ------> 2NH3(g) ; rH° = -92.4 KJ/mol

enthalpy of formation of NH3 means heat released in the formation of 1 mole of NH3 .

so, divide both sides by 2 in above reaction

1/2N2(g) + 3/2H2(g) ---> NH3(g) ;

Therefore , fH° = rH°/2 = -92.4/2 = 46.2 KJ/mol

Thank you.

Dear Aspirant,

As you have described that you have completed these many subjects it is just a matter of couple of more months that you'll be done with the syllabus however I would suggest you should slow down your pace as you're aiming for 2021. In general to prepare for gate a period of 8 months is sufficient with a 6 hours study everyday.

Since you are done with enough subjects, I suggest you should start to solve previous year gate questions from last 30 years. That will help you to be in the league and non forgetting what you have learned.

Also always revise what you have studied 3-4 weeks ago. It will strengthen your command over those topics. Do not stress yourself too much now, start pressing yourself in the month of July next year as your aim is 2021.

Hope this helps.

Feel free to comment your doubts.

Thank you.