Ch. 10, 14, & 19 thermodynamics & nuclear chem test [80 points] Honors Chemistry

Show your work in an organized manner, includes any relevant equation / formula, proper units in your work / answer, and the proper number of significant figures in your answer.

1. What information can be provided by: [9 points]

a. ∆ H

b. ∆ S

c. ∆ G

2. What does the equation: E = m c 2 mean ? [6 points]

 

3. What is ∆ S reaction: mix aqueous solutions of sodium phosphate and calcium chloride ? Justify your answer. [15 points]


4. KOH (s)  -->  K +(aq) + OH -(aq)      [15 points]

a. calculate ∆ H of the above reaction.

b. what is the amount of heat generated or consumed in the above reaction by dissolving 2.0 g solid KOH in water ?

c. what is the temperature of 45 g water at 25 °C, when 2.0 solid KOH was dissolved in water ?

 

5. write the nuclear reaction described below: [20 points]

a. 95Kr undergoes beta minus decay: _______________________

b. 80Rb undergoes beta plus decay: ________________________

c. 187Hg undergoes alpha decay: ________________________

d.   238Np -->  2 10n  +  95 Nb +  _____

e. 4He + 11B -->  __________

 

6. 35S has a half-life of 87 days. [15 points]

a. what is the decay constant of the isotope ?

b. 100. g 35S decays to 10.0 g 35S. What is the age of the object ?

c. how much time would it take for 250. g 35S to become 50.0 g 35S ?