2.1.3 - Amount of Substance Flashcards
What is stoichiometry?
Stoichiometry is the calculation of the quantities of reactants and products involved in a chemical reaction based on their molar relationships.
What does the stoichiometric ratio refer to?
The stoichiometric ratio refers to the ratio of moles of reactants to moles of products in a balanced chemical equation.
What is the molar ratio in a chemical equation?
The molar ratio is the ratio of the coefficients of the substances (reactants and products) in a balanced chemical equation.
How do you calculate the moles of a substance involved in a chemical reaction?
The moles of a substance can be calculated by using the stoichiometric ratio in the balanced equation and the amount (in moles) of another substance involved in the reaction.
What is the limiting reactant?
The limiting reactant is the reactant that is completely consumed first in a chemical reaction, limiting the amount of product that can be formed.
How do you identify the limiting reactant?
To identify the limiting reactant, compare the amount of each reactant available to the amount required according to the balanced equation. The reactant that runs out first is the limiting reactant.
What is the theoretical yield?
The theoretical yield is the maximum amount of product that can be produced from a given amount of reactants, calculated based on stoichiometry.
What is the actual yield?
The actual yield is the amount of product actually obtained from a chemical reaction, which may be less than the theoretical yield due to losses, side reactions, or incomplete reactions.
What is percent yield?
Percent yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage:
Percent yield = (Actual yield / Theoretical yield) × 100
What are reacting masses?
Reacting masses refer to the masses of the reactants and products involved in a chemical reaction. Stoichiometry allows the calculation of these masses.
How do you calculate the mass of a product in a reaction?
The mass of a product can be calculated using:
1- Convert the mass of a reactant to moles.
2- Use the stoichiometric ratio to find the moles of product.
3- Convert the moles of product to mass using its molar mass.
What is the molar mass used for in stoichiometry?
The molar mass is used to convert between the mass of a substance and the number of moles, allowing for calculations of reacting masses.
How do you convert grams to moles?
To convert grams to moles, divide the mass of the substance by its molar mass:
Moles = Mass (g) / Molar mass (g/mol)
How do you calculate the moles of a product from the moles of a reactant?
Use the stoichiometric ratio from the balanced equation to calculate the moles of product based on the moles of reactant.
For example, if the ratio is 1:2, double the moles of the reactant to get the moles of the product.
What is conservation of mass in a chemical reaction?
Conservation of mass states that mass is neither created nor destroyed in a chemical reaction. The total mass of the reactants is equal to the total mass of the products.
What is the significance of the coefficients in a balanced chemical equation?
The coefficients represent the stoichiometric ratio, indicating the number of moles of each reactant and product involved in the reaction.
How do you calculate the volume of a gas at standard temperature and pressure (STP)?
Use the formula:
Volume (dm³) = Moles × 22.4 dm³/mol at STP, where 22.4 dm³ is the molar volume of a gas at STP.
What is the ideal gas equation?
The ideal gas equation is:
PV = nRT
Where P is pressure, V is volume, n is moles, R is the gas constant, and T is temperature in Kelvin.
How do you calculate the volume of a solution from the number of moles and concentration?
The volume can be calculated using:
Volume (dm³) = Moles / Concentration (mol/dm³)
How do you calculate the concentration of a solution?
The concentration can be calculated using:
Concentration (mol/dm³) = Moles / Volume (dm³)
How do you convert cm³ to dm³?
To convert from cm³ to dm³, divide by 1000.
1 dm³ = 1000 cm³
What is the unit for concentration in stoichiometric calculations?
The unit for concentration is moles per liter (mol/L) or mol/dm³.
What does STP stand for in gas calculations?
STP stands for Standard Temperature and Pressure, which is 0°C (273 K) and 1 atm pressure.
What is the molar volume of a gas at STP?
The molar volume of a gas at STP is 22.4 dm³/mol. This is the volume that 1 mole of an ideal gas occupies at standard temperature and pressure.
What is Avogadro’s Law?
Avogadro’s Law states that equal volumes of gases, at the same temperature and pressure, contain the same number of molecules. This law is important for calculating the volume of gases in reactions.
