Understanding Moles in Chemistry-IGCSE

What is the formula to calculate moles from mass?

• moles = mass (g) * molar mass (g/mol)

• moles = mass (g) + molar mass (g/mol)

• moles = mass (g) - molar mass (g/mol)

• moles = mass (g) / molar mass (g/mol)

How many moles are in 32 grams of oxygen gas (O2)?

• 1 mole

• 4 moles

• 0.5 moles

• 2 moles

If you have 2 moles of a solid substance, how many grams do you have if its molar mass is 58 g/mol?

• 1160 grams

• 2 grams

• 58 grams

• 116 grams

What is the volume of 1 mole of an ideal gas at standard temperature and pressure (STP)?

• 15 liters

• 10 liters

• 22.4 liters

• 32 liters

How do you calculate the number of moles in a solution?

• moles = density (g/mL) × volume (L)

• moles = concentration (mol/L) × volume (L)

• moles = mass (g) / volume (L)

• moles = concentration (mol/L) + volume (L)

If you dissolve 5 grams of sodium chloride (NaCl) in water, how many moles of NaCl do you have?

• 0.0856 moles

• 0.2 moles

• 0.05 moles

• 0.1 moles

What is the relationship between moles and molecules?

• One mole contains 12 molecules.

• One mole is equal to 1,000 molecules.

• One mole is the same as 6.022 x 10^22 molecules.

• One mole contains approximately 6.022 x 10^23 molecules.

How many moles are in 22.4 liters of a gas at STP?

• 5 moles

• 0.5 moles

• 1 mole

• 2 moles

If you have 0.5 moles of a substance, how many molecules do you have?

• 3.011 x 10^23 molecules

• 2.5 x 10^23 molecules

• 6.022 x 10^22 molecules

• 1.204 x 10^24 molecules

What is the molar mass of carbon dioxide (CO2)?

• 18.02 g/mol

• 44.01 g/mol

• 28.02 g/mol

• 32.00 g/mol