Punchy

What is the free energy of the reaction of Cu2+ and Zn when the concentration of all metal ions in solution is 0.1M?

Determine the pH of a solution when 25.2 mL of 0.021 M HNO3 is mixed with 18.1 mL

of

A. 0.0110 M NaOH.

B. distilled water

C. 0.0100 M HCl

D. 0.132 M KOH

A sample of silver (with work function Φ=4.52 eV) is exposed to an ultraviolet light source (𝜆=200 nm),

which results in the ejection of photoelectrons. What changes will be observed if:

The silver is replaced with cobalt (Φ=5.00 eV)?

a) less energetic photoelectrons (on average)

b) fewer photoelectrons ejected

c) more energetic photoelectrons (on average)

d) no photoelectrons are emitted

e) more photoelectrons ejected

A second (identical) light source also shines on the metal?

a) less energetic photoelectrons (on average)

b) no photoelectrons are emitted

c) more photoelectrons ejected

d) more energetic photoelectrons (on average)

e) fewer photoelectrons ejected

The ultraviolet source is replaced with an X‑ray source that emits the same number of photons per unit time as the original ultraviolet source?

a) no photoelectrons are emitted

b) more energetic photoelectrons (on average)

c) more photoelectrons ejected

d) fewer photoelectrons ejected

e) less energetic photoelectrons (on average)

How can you analyze the force and motion of a single object in collision when force is not constant if you have force-time graph, position-time graph, and velocity-time graph.

A mixture was found to contain 1.05 g of silicon dioxide, 0.69 g of cellulose, and 2.17 g of calcium carbonate. Compute the mass percentage of oxygen in the mixture.

What is the oxidizing agent in the reaction

2MnO4−(aq) + 10I−(aq) + 16H+(aq) --> 2Mn2+(aq) + 5I2(aq) + 8H2O(l)?

A solid was found to be highly soluble in water. Treating separate portions of a solution of this solid with NaCl, NaBr, NaI, Na2SO4, Na2CO3, Na3PO4, NaOH, and Na2S produced no precipitates. Treatment of an aqueous solution of this solid with acid resulted in the formation of the foul-smelling gas H2S. This solid was:

a) (NH4)2S

b) KBr

c) Pb(NO3)2

d) Li2CO3

A geochemist looking for new minerals makes the following observations.

a. Sample A dissolves in hydrochloric acid, but no gas is released.

b. Sample B does not react with hydrochloric acid.

c. Sample C dissolves in hydrochloric acid and bubbles of a colorless, odorless gas form.

Based on these tests, what can be said about the chemical composition of each of these samples.

A salt solution results from the reaction between the "black solid" (heated malachite) and hydrochloric acid. Suggest a way to obtain the solid salt from this solution.

The labels have fallen off of three bottles thought to contain hydrochloric acid, or sodium chloride solution, or sodium hydroxide solution. Describe how you would determine which bottles contain which solutions.

A neutral atom has an electron configuration of [Rn]7s25f146d107p4. What Period 2 element is a member of the same group?

To 10.0 mL of 1.0 M aqueous hydrochloric acid enough pure, distilled water is added to make 1.0 L of solution. Does the pH rise or fall and by how many pH units?

The mass of a proton is 1.67 x 10^-27 kg. If its diameter is 1.0 x 10-15 m, calculate the density of the proton in units of g/cm3.

For the reaction 2H2(g) + O2(g) --> 2H2O, give a complete list of the bonds that are

broken and the bonds that are formed as the reactants are converted to product.