Limiting reactant of Chemical Reaction , Mole and volume of gases
Every chemical reaction needs accurately calculated amounts of reactants to obtain the required amounts of products , If the amount of one of the reactants increases than required , this extra amount remains as it is , without participation in the reaction .
The other reactant is completely consumed and determines the quantities of products formed and it is known as the limiting reactant .
It is the reactant which is completely consumed during the chemical reaction and reacts with other reactants to produce the lowest number of moles of the product .
The mole and volume of gases
The solid or liquid matter has a definite and constant volume , It can be measured by various methods , On the other hand , the volume of gases changes according to gases of the container .
Gas volume is directly proportional to the number of its moles when the temperature and pressure are constant .
The equal volumes of different gases contain the equal number of molecules , at the same standard temperature and pressure ( STP ) .
STP means Standard Temperature and Pressure that means temperature = 273 K which equals 0 degree Celsius and pressure = 760 mm.Hg which equals the normal atmospheric pressure ( 1 atm pressure ) .
The volume of one mole of any gas = 22.4 L at STP
This means that one mole from any gas at STP occupies a volume of 22.4 L , One mole from any gas contains 6.02 × 1023 molecules , If the number of moles is doubled , The volume doubled and the number of molecules also doubled .
Volume of gas ( at STP ) = no. of moles × 22.4 L
The molar volume is the volume occupied by one mole of the substance (the chemical element or the chemical compound) at the given temperature and pressure , Its symbol is Vm , The molar volume is equal to the molar mass (M) divided by the mass density (ρ) .