विलयन Solution | Chap 02 | L 03| 12th NEET 2021-22 | New Regular Course | Chemistry | Vikram Singh

Read the given information and decide the appropriate course of action. NEET examination has laid the following conditions to qualify for appearance in the NEET Exam. 1. Candidate should pass Grade 12 with a minimum of 50% marks in Biology, Physics and Chemistry group. 2. Candidate should have completed 17 years as on 31-03-2018. 3. Candidate should have opted for Biology, Physics and Chemistry in Grade 12. Candidate 1: Ram’s date of birth is 14-05-2001, with 40% marks in Mathematics, Physics, Chemistry and Biology. Candidate 2: Sham’s date of birth is 16-08-2000, with 60% marks in Biology, Physics and Chemistry. Who is eligible to write the NEET Exam?

In chemistry, 'mole' is an essential tool for the chemical calculations. It is a basic SI unit adopted by the 14^(th) general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12 g of ""^(12)C . 1 mole of a gas at STP occupies 22.4 litre volume. Molar volume of solids and liquids is not definite. Molar mass of a substance is also called gram-atomic mass or gram molecular mass. The virtual meaning of mole is plenty, heap or the collection of large numbers. 1 mole of a substance contains 6.022 xx 10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. XL N_(2) , gas at STP contains 3xx10^(22) molecules. The number of molecules in x L ozone at STP will be

According to the Avogadro's law , equal number of moles of gases occupy the same volume at identical conditions of temperature and pressure. Even if we have a mixture of non-reacting gases then Avogadro's law is still obeyed by assuming mixture as a new gas. Now let us assume air to consist of 80% by volume of nitrogen (N_(2)) and 20% by volume of oxygen (O_(2)) . If air is taken at STP , then its 1 mol would occupy 22.4 L . 1 mol of air would contain 0.8 mol of N_(2) and 0.2 mol of O_(2) hence the mole fraction of N_(2) and O_(2) are given by X_(n_(2))=0.8, X_(o_(2))=0.2 If air is treated as a solution of O_(2) and N_(2) , then % w/w of oxygen is: