Question

40g of NaOH is added in 460g of water if density of solurion 1g/ml. find out molarity of solution.

Answer 1

40g of NaOH is added in 460g of water

Molarity = moles of solute/volume of solution

So we need to find number of moles of NaOH(solute) and volume of the solution.
___________________________

Mass of NaOH = 40g

molar mass of NaOH = 23+16+1 = 40g

Number of moles of NaOH in 40g = 40/40 = 1 mole
____________________________

total mass of solution = 460 + 40 = 500g

density of solution = 1 g/ml

volume = mass/density = 500/1 = 500ml = 0.5L
______________________________

Now, molarity = moles of NaOH / Volume of solution

=> Molarity = 1 / 0.5 mol/L

=> Molarity = 2 mol/L

$\boxed{\textbf{ \red{Molarity = 2 \ mol/L}}}$

Answer 2

$\huge\mathcal{\fcolorbox{cyan}{black}{\pink{ĄNsWeR࿐}}}$

40g of NaOH is added in 460g of water

Molarity = moles of solute/volume of solution

So we need to find number of moles of NaOH(solute) and volume of the solution.

_________________

Mass of NaOH = 40g

molar mass of NaOH = 23+16+1 = 40g

Number of moles of NaOH in 40g = 40/40 = 1 mole

_________________

total mass of solution = 460 + 40 = 500g

density of solution = 1 g/ml

volume = mass/density = 500/1 = 500ml = 0.5L

_____________

Now, molarity = moles of NaOH / Volume of solution

=> Molarity = 1 / 0.5 mol/L

=> Molarity = 2 mol/L

$\boxed{\textbf{ \red{Molarity = 2 \ mol/L}}}$