Question

Find the molarity of water if density of water is 0.9 gram per ml

Answer 1

Answer:

0.05M

Explanation:

let us consider 100ml of water

mass of water =90g

no of moles of water =90/18=5

vol of water=mass/density

=900/0.9=100

molarity=5/100=0.05M

Answer 2

Answer:

the answer that someone had given to you is wrong .

The correct answer should me 50 M      you should take the volume in terms of litre and not in ml .

Explanation:

it is given that ,

density =0.9 gram per ml

let us consider 100 ml of water

we know that in this case ,mass of water = density * volume

                                                                    = 0.9 gram per ml * 100 ml

                                                                    = 90 gram

now formula to calculate molarity is

  M=number of moles / volume ( in litre )

so let us calculate number of moles

  number of moles =mass /molecular mass  ( here for water )

                               = 90/18  [since  molecular mass of H2O=18]

                               = 5 moles

again  volume of water = 100 ml =100/1000 litre = 0.1 litre

 

now ,

      molarity = 5/0.1

                     =50 M

you should know that unit for molarity is mole/litre or simply M

    HOPE YOU UNDERSTAND .