Avogadro's number is significant because it:

A. Represents the number of atoms in 12 grams of carbon-12.

B. Relates the macroscopic world to the atomic/molecular level.

C. Defines the number of electrons in one mole of electrons.

D. Represents the number of molecules in 1 gram of water.

Which of the following is the correct unit for molar mass?

A. g/mol

B. mol/g

C. g

D. mol

To determine the molar mass of an element using periodic table data, one should:

A. Take the atomic number of the element.

B. Take the number of neutrons in the element.

C. Take the relative atomic mass of the element.

D. Take the number of electrons in the element.

If you have 0.5 moles of sodium (Na), how many atoms of sodium do you have?

A. 0.5 x 6.02 x 10^23

B. 0.5 + 6.02 x 10^23

C. 0.5 - 6.02 x 10^23

D. 0.5 / 6.02 x 10^23

The mole concept is crucial in stoichiometry because:

A. It allows for the counting of individual atoms and molecules.

B. It defines the mass of one mole of a substance.

C. It provides a bridge between the atomic and macroscopic worlds.

D. It represents the number of electrons in an atom.

a) Define Avogadro's number and explain its significance in relating the macroscopic world to the atomic/molecular level. [3]

b) How can one determine the molar mass of an element using periodic table data? [2]

a) Differentiate between the terms 'mole' and 'molar mass'. [3]

b) If you have 12 grams of carbon, how many moles of carbon atoms do you have? [2]

a) Describe the importance of the mole concept in stoichiometry. [3]

b) If a chemical reaction requires 2 moles of hydrogen gas (H2) to produce 1 mole of water (H2O), how many moles of hydrogen gas would be needed to produce 5 moles of water? [2]

a) What is the significance of Avogadro's number in the context of the mole concept? [3]

b) Given that the atomic mass of magnesium is approximately 24.31, determine its molar mass. [2]

c) How many atoms are present in 0.5 moles of magnesium? [3]

a) Define the terms 'element', 'compound', and 'mixture'. [3]

b) How does the atomic theory explain the composition of compounds? [3]

c) If 3 moles of water (H2O) are decomposed, how many moles of hydrogen gas (H2) and oxygen gas (O2) would be produced? [3]