Answer:
1.926 g of NaOH
Step-by-step explanation:
Concept tested: Mole and Avogadro's number
- We need to know that , 1 mole of a compound contains number of molecules equivalent to the Avogadro's number.
- Th Avogadro's number is 6.022 × 10^23
Therefore;
- 1 mole of a compound = 6.022 × 10^23 molecules
In this case; Our compound is NaOH
Therefore;
1 mole of NaOH contains 6.022 × 10^23 molecules
But; Molar mass of NaOH is 40.0 g/mol
Therefore;
- 40.0 g of NaOH contains 6.022 × 10^23 molecules
With this we can calculate the mass of 2.90 × 10^22 molecules
- Mass of a compound = (number of molecules ÷ Avogadro's constant) × molar mass
Therefore;
Mass of NaOH =(2.90 × 10^22 molecules ÷ 6.022 × 10^23 molecules)40g
= 1.9263 g
= 1.926 g NaOH
Thus, the mass of NaOH is 1.926 g