Question

40g
of
NaOH
is
dissolved
to
make
a
2L
solution.
Find
the
molarity?

Does
it
change


with
change
in
temperature?​

Answer 1

Answer:

molarity = no.of moles of NaoH/volume of solutions in litres

molarity =given mass / molecular mass ×volume of solution

molarity=40/40×2

=0.5 M

molarity does not depend upon temperature so they do not change with temperature

Answer 2

Given:

40g of NaOH is dissolved to make a 2L solution.

To Find:

• Molarity of solution ?
• Does it change with temperature change?

Calculation:

First, let's find out the number of moles:

$\therefore \: moles = \dfrac{given \: mass}{molar \: mass}$

$\implies\: moles = \dfrac{40}{23 + 16 + 1}$

$\implies\: moles = \dfrac{40}{40}$

$\implies\: moles = 1 \: mol$

Now, lets find molarity:

$\implies \: molarity = \dfrac{moles}{volume\:of\: solution \: (in \: l)}$

$\implies \: molarity = \dfrac{1}{2}$

$\implies \: molarity = 0.5 \: M$

So, molarity is 0.5 M.

• Yes molarity will change with change in temperature.

• If temperature increases, the volume of solution will also increase and hence the molarity will decrease.