2.1.7 Practice: Chemical Reactions
Practice: Chemical Reactions
You will need to use a calculator and a periodic table to complete this activity.
1. Conditions around hydrothermal vents deep in the ocean floor can enable chemical reactions that produce solid materials. A student models one of these reactions by combining aqueous Ca(OH)2 and Na2SO4
, and observes the formation of a solid in a liquid.
a. Justify the choice of a net ionic equation for describing this reaction. (2 points)
b. Write and balance a net ionic equation for the reaction. Show your original equation as well as the balanced one. (3 points)
c. Explain the steps you took to balance the original unbalanced net ionic equation. (2 points)
2. Identify the oxidation numbers for each element in the following equations. Then determine whether each equation describes a redox reaction. Justify your answer in terms of electron transfer. Describe the oxidation and reduction that occurs.
a. Ca + 2HCl → CaCl2 + H2
(4 points)
b. 2KOH + K2Cr2O7 → 2K2CrO4 + H2O (4 points)
c. AgNO3 + KI → AgI + KNO3
(4 points)
d. 2PbS + 3O2 → 2PbO + 2SO2
(5 points)