General Chemistry Answers

10. Tin is used to coat tin cans for food storage. If the tin is scratched and the iron of

the can exposed, will the iron corrode more rapidly or less rapidly? Explain

9. Construct a galvanic cell using the following reactions. Look up E° values

(a) MnO4 (aq)

- + e

- → MnO4

2-

(aq)

(b) Zn

2+

(aq) + 2e- → Zn(s)

(i) What type of electrodes are used at the anode and cathode and why?

(ii) Write the reaction at the anode and cathode

(iii) Write the overall reaction and calculate the cell potential

(iv) Write the line notation for the reaction above

6. Give the balanced full reaction and calculate the E° for galvanic cells based on the

following reactions. Draw diagrams indicating; the anode, cathode, flow of electrons, salt bridge

(a) Zn

2+

(aq)+ 2e

-  Zn (s)

Pb

2+

(aq) + 2e

-  Pb(s)

(b) Cr2O7

- + 14H+ + 6e

-  2Cr

3+ + 7H2O

H2O2 + 2H+ + 2e

-  2H2O

In a titration experiment, an average of 15.2 mL of a 0.25 mol/L NaOH solution was needed to neutralize 20.0 mL of an unknown concentration of HCl. What is the molar concentration of the HCl solution?

A 50.0 mL solution of H₂SO₄ has a concentration of 2.00 mol/L. It is dilutedby adding 150mL of water. What is the molar concentration of the sulphuric acid after dilution?

Ammonia (NH₃) will react with water and cause phenolphthalein to turn pink. Using the Bronsted-Lowry Theory of acids and bases to write balanced equation of this reaction. Also, indicating each component as an acid, base, conjugate acid, or conjugate base.

Silver chromate, Ag₂CrO₄, is insoluble. It forms a brick-red precipitate. Calculate the mass of silver chromate that forms when 50.0mL of 0.100mol/L silver nitrate reacts with 25.0 mL of 0.150mol/L sodium chromate.

If 125.0mL of 0.500mol/L NaNo_3(aq) is mixed with 15.0mL of 0.250mol/L MgSO_4(aq),what is the concentration of sulfate ions in the final solution?

3. Calculate the maximum work available from 50.0 g of aluminum in the following cell when the cell potential is 1.15 V. Al(s) |Al3+ (aq) || H+ (aq) | O2(g) |Pt . Note that O2 is reduced to H2O. Use appropriate standard reduction potentials.

1. Iodic acid, HIO3, can be prepared by reacting iodine, I2, with concentrated nitric acid. The skeleton equation is: I2(s) + NO3 - (aq) → IO3 - (aq) + NO2(g). Balance this equation using the half reaction method.