05 05 Limiting Reactant Journal PDF

Preview

Summary

Download 05 05 Limiting Reactant Journal PDF

Description

Chemistry Journal 5.5 Limiting Reactant Driving Question: How do the limits of reactants affect the outcome of chemical reactions? Key Ideas and Terms Notes FQ: How do limiting reactants affect the outcome of chemical reactions? What is theoretical yield?

the maximum amount of product you would expect from the reaction due to a reactant running out before the others

What is the limiting reactant? the reactant that controls the amount of product that can be produced by a chemical reaction because it is used up completely

What is the excess reactant?

the reactant that is not used up completely in a chemical reaction

Video: Limiting Reactant 

Describe limiting reactant problems.

In a limiting reactant problem, there are given amounts of more than one reactant, and one will run out before the others. So, that reactant stops, or limits, the reaction, and it determines how much product can be made.

. 

According to the video, how do you identify the limiting and excess reactants of a reaction?

The reactant that can make less is the limiting reactant, and the reactant that could produce more is the excess reactant.



Show how the limiting reactant is determined for 3.80 g of magnesium reacting with 12.5 g of oxygen.

3.80 grams of magnesium can only produce 6.30 grams of magnesium oxide while 12.5 grams of oxygen gas would be able to produce 31.5 grams of magnesium oxide.

Which reactant is the limiting reactant and which is the excess reactant when there are 15.0 g of hydrogen gas and 10.0 g of nitrogen gas?

3H2(g) + N2(g) → 2NH3(g)

FQ: How do we use stoichiometry to help identify the limiting and excess reactants? Solving limiting reactant problems involves stoichiometry skills. To solve for limiting and excess reactants, you will repeat the same stoichiometry steps using the same product in the chemical reaction for all reactants

If 3.0 moles of HF react with 4.5 moles of SiO2, how many moles of SiF4 can be formed? Describe the steps. SiO2(s) + HF(g) → SiF4(g) + H2O(l)

What about the other product?

If 5 moles of carbon monoxide react with 2.3 moles of hydrogen gas, how many moles of methanol can be produced?

To find the mole amount of the second product, use the starting amount of the limiting reactant to calculate the amount for the second product.

CO + 2H2 → CH3OH FQ: How is stoichiometry used to find the mass of the theoretical yield? How is the mass of the theoretical yield determined?

If 35.0 grams of coal (carbon) burns in 58.5 grams of oxygen gas, how many grams of carbon dioxide can be produced? Describe the steps. C + O2 → CO2

Usually, when working with chemical reactions, we are given the masses of samples in the reaction. From here, we can determine the mass of the theoretical yield. But first, we must determine which reactant limits the reaction. The mass produced by the limiting reactant is the mass of the theoretical yield

Be sure to record any extra helpful notes, vocabulary terms, and practice sample problems....