Question

How many molecules are there in 65 g of silver nitrate (AgNO3)?

A. 

3.82 × 1023

B. 

2.3046 × 1023

C. 

2.3046 × 1024

D. 

3.82 × 1024

E. 

2.3046 × 1012

​

Answer 1

The correct answer is B, $2.3046 × 10^{23}$

The first step to solving this problem is to find the molar mass of AgN$O_{3}$. From the periodic table this can be found to be 169.87g/mol. As a reminder, Avogadro's Number tells us that there are 6.022×1$0^{23}$ molecules per mol.

Now you can set up dimensional analysis to solve the problem as follows:

$65g AgNO_{3} x \frac{1 mol}{169.87g AgNO_{3} } x \frac{6.022x10^{23}molecules }{1 mol}$ ≈ 2.304$6^{23}$

Answer 2

Answer:

B. 2.3046 × 1023