Practice Problem: Conversions Using Avogadro's Number

The video tutorial explains how to use Avogadro's number for conversions. It covers two main problems: calculating the number of gold atoms in a 5 kg brick and determining the number of carbon atoms in a 40 mg sample of saccharin. The tutorial guides viewers through the conversion process, including converting mass to moles using molar mass and then to atoms using Avogadro's number. It also provides tips for simplifying calculations and adjusting scientific notation.

What is the primary purpose of using Avogadro's number in chemical conversions?

• To calculate the density of a substance

• To determine the number of atoms or molecules

• To convert mass to volume

• To find the boiling point of a compound

How do you convert kilograms to grams in the context of molar conversions?

• Add 1000

• Multiply by 1000

• Divide by 1000

• Subtract 1000

What is the molar mass of gold used in the conversion process?

• 196.967 g/mol

• 183.18 g/mol

• 12.01 g/mol

• 6.022 g/mol

Why is scientific notation useful in chemical calculations?

• It is used to calculate temperature changes

• It helps in determining the chemical formula

• It increases the accuracy of measurements

• It simplifies the representation of very large or small numbers

What is the molar mass of saccharin used in the second question?

• 183.18 g/mol

• 196.967 g/mol

• 6.022 g/mol

• 12.01 g/mol

How many carbon atoms are present in one molecule of saccharin?

• 7

• 8

• 6

• 5

What is the final step to find the number of carbon atoms in the saccharin sample?

• Subtract 7 from the number of molecules

• Add 7 to the number of molecules

• Divide the number of molecules by 7

• Multiply the number of molecules by 7