Chem 103 Final exam review

1. Let’s Get Started
• Get in equal groups (let’s shoot for 7-8 people
each)
• Pull out a paper and write down the names of
the people in your group.
• Turn on gaming buzzer by holding the on/off
button for 5 seconds

2. 1) What is the pH range for acid?
2) For base?
3) neutral?

3. Answer
Less than 7 is acidic
Greater than 7 is basic
7 is neutral

4. In the following acid base
reaction, identify the Brønsted
Lowery acid and it’s conjugate
base
NH3 + H2S  NH4
+ + HS-

5. Answer:
Acid = H2S
Base = NH3
Conjugate Acid = HS-
Conjugate base = NH4
+

6. What is the pKa of a weak acid
with Ka of 6.5 x 10-5?

7. Answer
4.19

8. What are two definition of a
strong acid?

9. Answer
dissociates completely with water
to form H3O+ ions

10. In acid and base equilibrium, in
which direction does the
equilibrium favor?

11. Answer
The formation of weak acid and weak base

12. Household ammonia (NH3) has a
pOH of 3. What is the pH of
ammonia?

13. Answer
pOH + pH = 14
pH = 11

14. Solution A has a pH of 2 and solution
B has a pH of 4.
1) Which has a higher hydronium
concentration?
2) and how many times greater?

15. Answer
1) A
2) 100

16. 1) Complete the following reaction
and 2) what type of reaction is this.
KOH + HI  _____ + _____

17. Answer
1) KOH + HI  KI + H2O
2) Neutralization

18. Give 2 definitions of a base.

19. Answer
1) Produces OH- ions in aqueous
solutions
2) Proton acceptor

20. Substance A has a pKa of 2.3 and
substance B has a pKa of 3.4.
Which is the stronger acid?

21. Answer
A

22. 1) What is transmutation
2) And name two types of nuclear
reactions that result in
transmutation

23. Answer
1) When one element is turned into
another element through nuclear
reactions
2) Alpha, beta, and positron
emission and electron capture

24. What has the greatest
penetrating power?
Alpha, beta, or gamma

25. Answer
Gamma > beta > alpha

26. What can cause the most
damage in the body?
Alpha, beta, or gamma

27. Answer
Alpha > beta > gamma

28. What is gamma radiation?
How does it differ from alpha
and beta radiation?

29. Answer
-gamma radiation is part of the electromagnetic
spectrum, it has no mass or charge
-beta radiation is a particle similar to an
electron and has negligible mass and -1 charge
-Alpha radiation is essentially a helium atom
with a mass of 4 and a charge of -2

30. If the half life of 100.0 grams of a
radioactive isotope is 8 years, how
many grams will remain after 32
years?

31. Answer
6.25 g

32. Tungsten-188 is beta emitter.
Complete this nuclear reaction.

33. Answer
W188
74
0
-1
+ Re188
75

34. What isotope is formed from the
alpha decay of Radium-222?

35. Answer
Radon-218

36. A buffer is composed of formic acid
and its conjugate base, the formate
ion. What is the pH of a solution
that has a formic acid concentration
of 0.05 M and a sodium formate
concentration of 0.035 M?
The Ka of formic acid is 1.8 x 10-4.

37. Answer
3.59
pH = 3.74 + log (.035/.05)
pH = 3.74 – 0.15