How many moles are in 1.50 x 1023 molecules NH3?

A.

2.49 x 10 -1 mol NH3

B.

2.49 x 101 mol NH3

C.

2.65 x 10 -1 mol NH3

D.

2.78 x 10 1 mol NH3

1 mol contains 6.02

E23 molecules.

To find the number of moles in 1.50 x 10^23 molecules of NH3, we can use Avogadro's number, which states that 1 mole of any substance contains 6.022 x 10^23 particles.

Given:
Number of molecules (N) = 1.50 x 10^23 molecules

To calculate the number of moles (n), we can use the formula:

n = N / (Avogadro's number)

Substituting the values:
n = 1.50 x 10^23 molecules / (6.022 x 10^23 molecules/mol)

Simplifying and rounding the answer to two significant figures gives us:

n ≈ 0.25 mol NH3

Therefore, the correct answer is option A: 2.49 x 10^-1 mol NH3.

To find the number of moles in a given number of molecules, you need to use Avogadro's number, which states that there are 6.022 x 10^23 particles in one mole of a substance.

In this case, you are given 1.50 x 10^23 molecules of NH3. To convert this to moles, divide the number of molecules by Avogadro's number:

1.50 x 10^23 molecules NH3 / 6.022 x 10^23 molecules/mol = 0.249 mol NH3

The correct answer is therefore:
A. 2.49 x 10^-1 mol NH3