Dear aspirant !

Hope you are doing great ! You should know the formula first and that is n =N/Na where n is the no . Of moles which is equal to given mass / molar mass and N is the no. Of molecules asked in the question and Na is avogadro number which is a constant . Compare both given mass / molar mass =N/ Na , keep the N one side put all the values ,and you will get lithium as your answer .

Hope it helps you !

Thank you

Hi!!!

Hope you are doing well.

100 atoms of A+ 100 molecules of B means 100 atoms of A will react with 100 molecules of B. Thus, both the reagents are present in stoichiometric amounts.

Hope you are clear now. Feel free to ask if you have any other queries. All The Best!!!

Hi aspirant,

To understand this we must understand the difference between an atom and a molecule. Atom is the smallest unit of ordinary matter that forms a chemical element which maybe solid-liquid or gas. The atoms are divided into three parts internally but that is not taken into general consideration while division. Now talking about molecules, they are electrically neutral group of two or more atoms held together by chemical bonds. These molecules may be same or different from each other.

So if we say 100 atoms of a, it refers to 100 singular particles of same nature. Eg-- N

100 molecules of B means that 100  groups of different atoms come together to form a unit. Eg--N2

Hope it helps!!

Hello,

The seperation coefficients of benzoic acid in partially miscible two phase mixtures of (methanol + cyclohexane) were measured at the temperature of 293.15, 303.15, and 313.15 K. The inventive outcome show that the benzoic acid is more soluble in methanol than in cyclohexane and thus it makes the seperation coefficients, defined as the ratio of the total molar concentration of benzoic acid in methanol phase to cyclohexane phase, be greater than unity.

thank you.

Hello student ,

Generally 1 mole of a substance contains Avogadro Number of molecules that is 6.022 × 10^23 therefore

1. 28g of N2 = 1 mole = 6.022×10^23 molecules.                             Therefore 7g of N2 = 7/28 = 0.25 mole =  6.022× 10^23/4 = 1.505×10^23 molecules .
2. 2g of H2 = 1 mole = 6.022×10^23 molecules
3. 16g of O2 = 1 mole = 6.022×10^23 molecules            Therefore 8g of O2 = 8/16=0.5mole = 6.022×10^23/2= 3.011×10^23 molecules.
4. 46g of NO2 = 1mole=6.022×10^23 molecules            Therefore 20g of NO2 = 20/46=0.434 moles = 6.022×10^23*0.434= 2.6×10^23 molecules

Thus 2g of H2 has the highest number of molecules among the given elements/compounds

A material at a certain temperature does not have all of its particles at the same energy. In the basic definition of the word, "temperature" is the average random motional (kinetic) energy of the particles of a material. (Thermodynamics gives a broader definition to temperature, but we don't need this definition here.) Did you notice the word "average" in the basic definition? Just because we can assign a single number to the temperature of an object that is in thermal equilibrium does not mean that every atom of the material is moving with the same energy because of the nature of averaging. If the average height of everyone in the room is 5 feet 9 inches, this does not imply that everyone in the room is 5 feet 9 inches tall. Some people will be 6 feet tall while others will be 5 feet 6 inches tall. The average of a set of a values only gives us a general idea of the group as a whole and does not tell us about any individual in the group. In the same way, the atoms in a material are all moving at different speeds and with different energies, even when the material has a constant and uniform temperature. Some of the atoms are moving faster than the speed corresponding to the material's temperature and some of the atoms are moving slower. A few of the atoms are moving much faster than what is implied by the temperature.