moles Flashcards
(24 cards)
What is the definition of a mole?
A mole is a unit of measurement in chemistry that represents 6.022 x 10^23 particles, atoms, or molecules.
True or False: A mole is equivalent to 12 grams of carbon-12.
True.
What is Avogadro’s number?
Avogadro’s number is 6.022 x 10^23, which is the number of atoms, ions, or molecules in one mole of a substance.
Fill in the blank: The mole is a fundamental concept in _____ that relates mass to the number of particles.
stoichiometry.
What is the mole ratio in a balanced chemical equation?
The mole ratio is the ratio of the coefficients of reactants and products in a balanced chemical equation.
Calculate the mole ratio of hydrogen to oxygen in the balanced equation 2H2 + O2 → 2H2O.
The mole ratio of hydrogen to oxygen is 2:1.
True or False: The coefficients in a balanced equation represent the number of moles of each substance.
True.
What is the significance of Avogadro’s number in chemistry?
Avogadro’s number allows chemists to count particles by weighing them.
In the reaction 4Fe + 3O2 → 2Fe2O3, what is the mole ratio of iron to oxygen?
The mole ratio of iron to oxygen is 4:3.
Fill in the blank: The concept of the mole helps bridge the gap between _____ and _____ in chemistry.
the macroscopic world; the microscopic world.
What is the molar mass of a substance?
The molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol).
True or False: One mole of any substance contains the same number of entities, regardless of the substance.
True.
What is the relationship between moles and mass?
Mass (in grams) equals the number of moles multiplied by the molar mass.
Calculate the number of moles in 18 grams of water (H2O).
There are 1 mole of water in 18 grams.
What does the term ‘stoichiometry’ refer to?
Stoichiometry refers to the calculation of reactants and products in chemical reactions based on balanced equations.
Fill in the blank: The balanced equation 2Na + Cl2 → 2NaCl indicates that 2 moles of sodium react with _____ mole of chlorine.
1.
What is the mole ratio of products to reactants in a balanced chemical equation?
It is determined by the coefficients of the balanced equation.
True or False: The mole is only used for measuring gases.
False.
What is the formula to convert grams to moles?
Moles = mass (g) / molar mass (g/mol).
Calculate the mole ratio of nitrogen to hydrogen in the balanced equation N2 + 3H2 → 2NH3.
The mole ratio of nitrogen to hydrogen is 1:3.
Fill in the blank: A mole of any gas at standard temperature and pressure occupies _____ liters.
22.4.
What is the purpose of using mole ratios in calculations?
Mole ratios are used to convert between amounts of reactants and products in chemical reactions.
True or False: The concept of moles is only applicable to solids.
False.
What is the molar mass of carbon dioxide (CO2)?
The molar mass of CO2 is 44.01 g/mol.
