Question

1. You titrate a 10.00 mL sample of a solution of borax with HCl. If it requires 24.89 mL of 0.100 M HCl to reach the endpoint, calculate Ksp for borax.

______M

2. Considering the information given and the calculations performed, how many significant figures should properly be reported for the answer to the previous question.

A. 2

B. 3

C. 4

D. 5

3. You measure K_sp for borax to be 7.8 x 10^-3 and 2.9 x 10^-3 at 23.6°C and 1.8°C, respectively. Calculate the standard enthalpy change, ΔH°, (in kJ) for the dissolution of borax.

________kJ

4. You measure K_sp for borax and find it to be 6.2 x 10^-3 at 22.8°C. If the standard enthalpy change, ΔH°, for the dissolution of borax is 58 kJ, calculate the standard entropy change, ΔS°, (in J/K) for the dissolution of borax at this temperature. (Assume ΔH° is independent of temperature.)
_______________ J/K

5.You drop a piece of zinc metal into a 1 M solution of copper(II) sulfate and notice that a black film forms on the surface of the piece of zinc. Which of the following best describes the chemical reaction that is happening?

A. Zinc metal is being reduced and copper(II) ion is being oxidized.

B. Zinc metal is being oxidized and copper(II) ion is being reduced.

C. Copper metal is being reduced and zinc ion is being oxidized.

D. Copper metal is being oxidized and zinc ion is being reduced.

6. A galvanic cell is constructed as follows:

One half-cell consists of a strip of magnesium metal immersed in a 1 M solution of magnesium sulfate. The other half-cell consists of a strip of zinc metal immersed in a 1 M solution of zinc sulfate. The two half-cells are connected with a salt-bridge and the two electrodes are connected with a wire.

Which of the following statements is correct with regard to this galvanic cell?

A. Zinc metal is produced at the anode and magnesium ions are produced at the cathode.
B. Zinc metal is produced at the cathode and magnesium ions are produced at the anode.
C. Zinc ions are produced at the cathode and magnesium metal is produced at the anode.
D. Zinc ions are produced at the anode and magnesium metal is produced at the cathode. 7. Calculate the potential (in V) of the following cell at 25°C. Zn(s) | Zn2+(1.0 M) || Cu2+(1.0 M) | Cu(s) The standard potential for the reduction of Zn2+ to Zn is -0.76 V. The standard potential for the reduction of Cu2+ to Cu is 0.34 V. ______________V WHOEVER YOU ARE, YOU ARE A LIFESAVER! THANK YOU! <3

Answer 1

question 6. option d is correct