Question

Chemical Quantities "Molar Mass - 2 step" - Wksh #3 Directions: Use dimensional analysis to perform the following calculations. Show all work, (K and U) include your units and box your final answers. 1. How many molecules are in 13.5 g of sulfur dioxide, SO2? 2. What is the mass of 2.23 x 1023 atoms of sulfur? 3. How many formula units of silver fluoride, AgF, are equal to 42.15 g of this substance? 4. What is the mass of 8.83 x 1023 formula units of Iron (III) oxide, Fe2O3?

Answer 1

There are about 1.27  × 10^23 molecules present in 13.5 g of SO2.

What are molecules?

A molecule is the simplest part of a compound that have independent existence.

Number of moles of sulfur dioxide = 13.5 g/64 g/mol = 0.211 moles

If 1 mole of SO2 contains 6.02 × 10^23 molecules

0.211 moles of SO2 contains 0.211 moles × 6.02 × 10^23 molecules/1 mole

= 1.27  × 10^23 molecules

32 g of sulfur contains 6.02 × 10^23 atoms

x g of sulfur contains  2.23 x 10^23

x = 32 × 2.23 x 10^23 /6.02 × 10^23

x = 11.85 g

6.02 × 10^23 formula units has a mass of AgF = 127 g

x formula units has a mass of  = 42.15 g

x = 6.02 × 10^23 × 42.15/127

x = 2 × 10^23 formula units

6.02 × 10^23 formula units of Fe2O3 has a mass of 160 g

8.83 x 10^23 formula units of Fe2O3 has a mass of 8.83 x 10^23 x 160 g/6.02 × 10^23

x = 235 g

Learn more about formula unit: brainly.com/question/19293051