Question

How many grams are 7.00 x 1022 molecules of NaOH?

a
46.5
b 6.65
C 7.0
d 4.65
e 11.6

Answer 1

`\huge{ \boxed{4.64 \: g}}`

Step-by-step explanation:

The number of grams of NaOH can be found by using the formula;

mass = number of moles × molar mass

Molar mass of NaOH = 40 g/mol

Since the number of particles was given the number of moles of the compound can be found by using the formula;

`n = (N)/(L)`

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question;

N = 7.00 × 10²² molecules

`\therefore \: n = \frac{7.00 * {10}^(22) }{6.02 * {10}^(23) } \\ = 0.116 \: moles`

The number of moles attained is then substituted into the formula for finding the mass of the compound.

`\therefore \: mass = 0.116 * 40 = 4.64 \: g`