HARD
Earn 100

Calculate the relative molecular mass of Glauber's salt. 

Important Questions on Some Basic Concepts of Chemistry

EASY
Which symbol replaced the unit of atomic mass, amu?
EASY

Calculate:

Mass of 5 gram atoms of calcium.
[Hint: Gram atoms mass: Ca=40 g]

MEDIUM
Two elements A and B which form 0.15 moles of A2B and AB3 type compounds. If one mole of each A2B and AB3 weigh equally, then the atomic weight of A is____times of atomic weight of B.
EASY

Calculate:

How many gram atoms of sodium is present in 115 g sodium?

EASY
Calculate mass of 3.01×1024 atoms of an element having atomic mass 21.13.
EASY
The unit of atomic mass, amu is replaced by u, here u stands for
EASY

A and B react to produce C according to the following chemical equation 
2A + B  2C

A, B and C are the formulas for three gaseous substances. The vapour densities of A and B are 32 and 16 respectively. Find out the vapour density of C. 

EASY
The common isotopes of carbon are C12 and C13. The average mass of carbon is 12.01115 amu. What is the abundance of the C13 isotope?
EASY
The element whose gram-atomic mass and gram-molecular mass are the same is-
HARD
An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this substance is subjected to complete combustion.
EASY
If 0.228 g of silver salt of dibasic acid gave a residue of 0.162g of silver on ignition, then molecular weight of the acid is
EASY
116mg of a compound on vaporisation in a Victor Meyer's apparatus displaces 44.8 ml of air measured at S.T.P. The molecular weight of the compounds is
EASY
Number of atoms of He in 100 u of He (atomic weight of He is 4) are
EASY
Tabulate the difference between gram-molecular mass and relative molecular mass.
EASY
An alkane has a CH ratio (by mass) of 5.1428. Its molecular formula is
EASY
Accurate determination of atomic masses is done with the instrument called as-