The energy (J) required for an electronic transition in a Bohr ...

[daltonest1984]

The energy (J) required for an electronic transition in a Bohr hydrogen atom from n = 1 to n = 3 is ________ J.
 
  A) -8.90  10-1
  B) 3.00  10-19
  C) -3.00  10-19
  D) 1.94  10-18
  E) 8.90  10-1

Question 2

Consider an electrochemical cell based on the reaction: 2H+ (aq) + Sn (s)  Sn2+ (aq) + H2 (g) Which of the following actions would not change the measured cell potential?
 
  A) lowering the pH in the cathode compartment
  B) addition of more tin metal to the anode compartment
  C) increasing the tin (II) ion concentration in the anode compartment
  D) increasing the pressure of hydrogen gas in the cathode compartment
  E) Any of the above will change the measured cell potential.

Question 3

A 0.1 M solution of ________ has a pH of 7.0.
 
  A) Na2S
  B) KF
  C) NaNO3
  D) NH4Cl
  E) NaF

[bitingbit]

Answer to Question 1

D

Answer to Question 2

B

Answer to Question 3

C