How many atoms are there in 4 grams of NaOH? M (NaOH) = – 40 g / mol

1. The sodium hydroxide molecule consists of three atoms: Na, O and H;

2.Find the chemical amount of 4 g of hydroxide:

n (NaOH) = m (NaOH): M (NaOH);

n (NaOH) = 4: 40 = 0.1 mol;

3. find the number of moles for 3 atoms:

n (NaOH atoms) = n (NaOH) * 3 = 0.1 * 3 = 0.3 mol;

4.Calculate the number of atoms in a portion of the hydroxide:

N (NaOH atoms) = n (NaOH atoms) * Na, where Na is Avogadro’s constant;

N (NaOH atoms) = 0.3 * 6.02 * 10 ^ 23 = 1.8 * 10 ^ 23.

Answer: 1.8 * 102 ^ 3 atoms.