Question

(i)What is the number of molecules in 18.0 g of caustic soda(NaOH)?

Answer 1

FIRST FIND OUT OUT THE MOLAR MASS OF NaOH.

${23 + 16 + 1 } \: \\ = 40$

SO MOLAR MASS OF NaOH IS 40g/mol. NOW DIVIDE THE GIVEN MASS. BY MOLAR MASS i.e.

$\frac{18}{40}$

NOW MULTIPLY IT BY AVOGADRO NUMBER TO GET THE ANSWER.

$6.022 \times {10}^{23} \times 0.45 \\ = 2.70 \times {10}^{23}$

SO OUR REQUIRED ANSWER IS

$2.70 \times {10}^{23}$

HOPE IT HELPS.

MARK AS BRAINLIEST.