Lab Quiz

Question 1

How do u calculate delta H

Answer 1

=-m*R
M is in K, and = to slope
R is the constant and in J/Mol/K
Delta H is in J/mol

Question 2

How do you find slope given delta H?

Answer 2

• delta H/R

Question 3

How do you find delta S? Entropy

Answer 3

b * R

B is the y-intercept and R is the constant

Question 4

How do you find the y intercept

Answer 4

Delta S /R

Question 5

How do you find initial conc after mixing big before reaction

Answer 5

Stock conc * (Vscn or Fe / V total)

Question 6

What is the reaction? Colors?

Answer 6

Fe 3+ (pale yellow) + SCN (colorless) = [Fe(SCN)]2 (pink - red)

Question 7

What is every variable for Ln (K) calf?

Answer 7

Delta H/R = m
1/T= x
Delta S/R= b

Question 8

How is X found for the ICE table?

Answer 8

X is found from A= e b c
C = x, c = A/(e b)
e is 2200
b= 1

Question 9

How do you read the graph?

Answer 9

b is at the origin

Slope is the trend line

Question 10

How to find k eq given info and temp

Answer 10

1:1 ratio so Fe reacted = SCN reacted
Do diluted - reacted, finding reacted from A/ e b

Put new values into K equation

Question 11

How does adding SCN affect the reaction

Answer 11

Q will be momentarily less than keq, shifting the reaction towards products
Solution gets darker

Question 12

How does adding NaOH affect the eq

Answer 12

It will react with Fe, forming fe(OH)3 causing the eq to shift left and the concentration of fe to decrease
Solution will be lighter

Question 13

How does Keq change with temp

Answer 13

Proportional so if one increases the other decreases

Conc and temp