# Limiting Reagent Problem Set

This problem set was developed by S.E. Van Bramer for Chemistry 145 at Widener University.

1. The Kingston Steam Plant burns 14,000 tons of coal each day and generates 1010 kilowatts-hours of electricity each year (enough for 700,000 homes). Coal is primarily carbon which undergoes combustion in the following reaction:

C(s) + O2 (g) -> CO2(g)

1. How many grams of oxygen is required for the combustion of 1 day's coal?
2. How much carbon dioxide is produced each day?

2. CO2 is removed from the atomsphere by trees and converted into cellulose. The basic reaction for this is:

6 CO2 (g) + 5 H2O (l) -> C6H10O5 (s) + 6 O2 (g)

1. How many grams of water are required to process the CO2 from one day's electrical production at the Kingston Steam Plant?
2. How much oxygen is produced by this process?
3. How much cellulose is produced?
4. If you assume that a tree weigh's 2 tons, how many trees are required to process the CO2 produced in one day?

3. A typical automobile gets 30 miles per gallon of gas and drives 12,000 miles every year. Assuming that octane (C8H18, density 0.7025 g cm-3) is a principal component of gasoline;

1. How much oxygen is required for a car to run for 1 year?
2. How much CO2 is produced by the car in 1 year?
3. How many trees are required to remove the CO2 produced by the car in 1 year?

4. Modern instrumental techniques are capable of detecting lead in a milliliter sample at picomolar concentration.
1. How many moles of lead are in the sample?
2. What is the mass of lead in this sample?
3. How many grams of sodium chloride would be required to precipitate all the lead in this sample as lead (II) chloride?
4. What would the mass of the lead (II) chloride precipitate be?

Please send comments or suggestions to svanbram@science.widener.edu

Scott Van Bramer
Department of Chemistry
Widener University
Chester, PA 19013