Chemistry PLTL Workshop 8

Redox Reactions

100

How can you recognize if a reaction is a redox reaction?

Since redox reactions involve the transfer of electrons within a chemical equation, the oxidation states of some elements in the reactants are different from the oxidation states of some of the elements in the products.

200

Identify the oxidation number of each element in the following molecule:

CO₂

Carbon: +4

Oxygen: -2

300

Identify the oxidation number of each element in the following molecule:

HCO₃^-

Hydrogen: +1

Carbon: +4

Oxygen: -2

400

Identify the reducing agent and oxidizing agent in the following reaction:

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Reducing agent: CO

Oxidizing agent: Fe₂O₃

500

Write out half-redox reactions for the following reaction:

_Mg + _O₂ → _MgO

Oxidation: Mg → Mg²⁺ + 2e^-

Reduction: O₂ + 4e^- →  2O^-

Throwback Q's

100

Is the following compound soluble or insoluble in water? Write out its formula.

Ammonium hydroxide

Soluble

NH₄OH

200

Identify the formula and molar mass of the following compound:

Rubidium sulfite

Rb₂SO₃

~251 g/mol

300

A nurse practitioner prepares an injection of promethazine, an antihistamine used to treat allergic rhinitis. If the stock bottle is labeled 25 mg/mL and the order is a dose of 12.5 mg, how many milliliters will the nurse draw up in the syringe?

USE SIG FIGS

0.50 mL

400

Identify the number of molecules in 0.50 kg of sugar (C₁₂H₂₂O₁₁).

USE SIG FIGS

8.8 x 10²³ molecules of sugar

500

After running a purification of mutant protein obtained from E. coli cells, you collect 78 ug of mutant protein. The protocol you followed estimates you should have obtained 0.15 mg of product. What is the percent yield of the purification?

52%