Deducing Stoichiometry Flashcards

All 5 cards in this deck

What is the stoichiometry of a reaction?

The ratio of the numbers of moles of the reactants and products, shown by the balancing numbers in the equation.

What are the steps to deduce the stoichiometry of a reaction from masses?

e.g. 4.8 g Mg gives 8.0 g MgO ($A_r$ Mg = 24, $M_r$ MgO = 40)

1. Convert each mass to moles: $4.8/24 = 0.2$; $8.0/40 = 0.2$
2. Divide by the smallest to get the simplest whole number ratio: Mg : MgO $= 1 : 1$

When deducing stoichiometry, how do you find the mass of a reactant that was not measured directly?

Use conservation of mass: total mass of products minus the mass of the reactant that was measured.

True or false? The mole ratio deduced from experimental masses gives the balancing numbers for the equation.

True. The simplest whole number mole ratio is the stoichiometry of the balanced equation.

In hydrated copper sulfate, $\mathrm{CuSO_4.5H_2O}$, what does the formula tell you about moles?

Each mole of $\mathrm{CuSO_4.5H_2O}$ contains 5 moles of water.