### Some basic concept of chemistry

$$\text {Temperature in } ^{ o}F = {(\frac{9}{5}}) ^{ o}C + 32$$ $$\text{Relative atomic mass }= \frac{\text{Mass of an atom of the element}}{\frac{1}{12} \text{x Mass of an atom of carban(C-12)}}$$ $$\text{Number of gram molecules }= \frac{W(g)}{ \text{ Gram molecular mass}}$$ $$\text{Number of gram atoms} = \frac{W(g)}{ \text{ Gram Atomic Mass(GAM)}}$$ $$\text{Avogadro's number } N_{\,A} = 6.022 X 10 ^{23}$$ $$\text{Mass of one atom of element } = \frac{GAM}{ N_{\,A} }$$ $$\text{Mass of one molecule of substance } = \frac{GMM}{ N_{\,A}} \text{ ( where GMM is Gram molar mass)}$$ $$\text{Number of molecule in W(g) of substance } = \frac{W(g) \text{x} N_{\,A}} {GMM}$$ $$\text{Mass % of an element in a compound } = \frac{ \text{Mass of that element in 1 mole of compound}} { \text{Moler mass of the compound }} \text{x 10}$$ $$\text{Mass percent } = \frac{\text{Mass of solute}} { \text{Mass of solution }} \text{x 100}$$ $$\text{Molarity(m) } = \frac{\text{Number of moles of solute}} { \text{Mass of solvent in kg}}$$ $$\text{Molecular mass } = \text{2 x vapour density}$$