Question

calculate the molarity of pure water if its density at room temprature is 1.0gcm

Answer 1

Given ;-

Molarity of pure water if its density at room temperature is 1.0 g/ cm ³.

To find :-

Molarity of pure water = ?

Sol ;-

Molarity = No. of moles of solute / Volume of solution 
        
 Before finding the Molarity let us find the mass of one litre of water  -  so therefore,

Mass of 1 litre  = Density of water × volume 
                     
                       = 1 kg / L × 1 L
     
        1 kg         =   1000 grams
 

⇒  Mass of 1 kg of water  =          Mass / Molar Mass
             
                                           =          1000 / 18
            
                                           =          55.56 

⇒ Molarity of water                    =          55.56 / litre


 

Answer 2

how can we change it into kg . to find moles mass is always in grams