Stoichiometry and Chemical Reactions

These flashcards cover key concepts related to stoichiometry, chemical reactions, and related calculations.

What is stoichiometry?

The calculation of reactants and products in chemical reactions.

What do you need to calculate the mass of a product from the mass of a reactant?

Mole ratio from the balanced chemical equation, molar mass of the reactant, molar mass of the product.

What is the formula for balancing chemical equations?

Write a preliminary expression, count atoms on both sides, balance one element at a time, adjust coefficients.

What chemical equation represents the process of photosynthesis?

6 CO2(g) + 6 H2O(l) → C6H12O6(aq) + 6 O2(g).

What is a limiting reactant?

The substance that is completely consumed in a chemical reaction and determines the amount of product formed.

In the combustion of methane, what is the balanced equation?

CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g).

What is required to determine the limiting reactant?

The number of moles of reactants and the stoichiometry of the balanced chemical equation.

What is the theoretical yield?

The maximum amount of product that could be obtained from given quantities of reactants.

What is percent yield?

The ratio of the actual yield to the theoretical yield multiplied by 100%.

How is percent composition calculated?

Mass of the element divided by the total mass of the compound, multiplied by 100%.

What is the empirical formula?

The smallest whole-number ratio of elements in a compound.

How can you determine the empirical formula from mass percentages?

Assume a 100 g sample, convert masses to moles, and find the smallest whole-number ratio.

What is the significance of phase symbols in chemical reactions?

They indicate the physical states of the reactants and products.

What did cyanobacteria contribute to the carbon cycle?

They were among the first organisms capable of photosynthesis.

How do you calculate the mass of CO2 produced from carbon combustion?

Use the mass of carbon consumed and stoichiometry relations to find the mass of CO2.

What is the purpose of using coefficients in balancing equations?

To ensure the same number of atoms for each element on both sides of the reaction.

What is meant by 'excess' ingredients in a reaction?

Ingredients that are not completely consumed in a chemical reaction.

How do you find the molecular formula from the empirical formula?

Multiply the empirical formula by n, where n is the ratio of the molar mass to the mass of the empirical formula unit.

What is the role of molar mass in stoichiometry?

It allows conversion between grams and moles of substances.

In a reaction, what does the term 'actual yield' refer to?

The amount of product actually obtained from a reaction.

What is the percent yield if the actual yield is 50 g and the theoretical yield is 75 g?

Percent yield = (50 g / 75 g) × 100% = 66.67%.

What is the empirical formula of a compound with 69.94% Fe and 30.06% O?

Fe2O3.

What are the steps to determine the limiting reactant?

Calculate the mass of product each reactant can produce, the one producing the lesser value is limiting.

What is the chemical equation for the combustion of carbon?

C(s) + O2(g) → CO2(g).

What does 'stoichiometry' refer to in a chemical reaction?

The quantitative relationship between reactants and products.

How do you convert grams to moles?

Use the formula: moles = mass (grams) / molar mass (g/mol).

What does the term 'empirical formula' represent?

The simplest whole number ratio of atoms in a compound.

What chemical reaction produces aluminum bromide from aluminum and bromine?

6.0 g of aluminum reacts with bromine to yield aluminum bromide.

If 10.0 g of CH4 is burned in 20.0 g of O2, what is necessary to find the limiting reactant?

Balanced chemical reaction and mass comparisons of products produced.