Question

Find the number of moles in 8 g of KOH (K=39u, O=16u, H=1u)

Answer 1

Step-by-step explanation:

No. of moles in 8g of oxygen atom

n=

M

m

×N

A

⇒

16

8

×6.02×10

23

=3.01×10

23

moles

ii) 6.02×10

23

atoms contains 1 mole

Then, 4.088×10

21

atom contains =

6.02×10

23

4.088×10

21

=0.67×10

−2

moles

Answer 2

Given - Mass of potassium hydroxide - 8 gram

Elemental weight of atoms - K - 39u, O - 16u, H - 1u.

Find - Number of moles in 8 gram of potassium hydroxide.

Solution - Number of moles of compound can be calculated by the formula - Weight of given compound/Molecular weight of given compound.

Molecular weight of potassium hydroxide - 39+16+1

Molecular weight of potassium hydroxide - 56 g/mol

Keeping the values in equation-

Number of moles - 8/56

Number of moles - 0.14.

Hence, number of moles in 8 gram of potassium hydroxide is 0.14