Straighterline Chemistry Final- deck 3| Questions Answered 100% Correct/Verified Solutions

Straighterline Chemistry Final- deck 3|
Questions Answered 100%
Correct/Verified Solutions

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the
solution after 15.00 mL of acid have been added to the ammonia solution?
[Kb(NH3) = 1.8 × 10-5]
Select one:
a. 10.26
b. 9.30
c. 9.21
d. 8.30
e. 8.21 - ANSWER a. 10.26


When a strong acid is titrated with a weak base, the pH at the equivalence point
Select one:
a. is greater than 7.0.
b. is equal to 7.0.
c. is less than 7.0.
d. is equal to the pKa of the conjugate acid.
e. is equal to the pKb of the base. - ANSWER c. is less than 7.0.



A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH.
What is the pH of this buffer? [Ka(CH3COOH) = 1.8 × 10-5]
Select one:
a. 4.57
b. 4.52
c. 4.87

,d. 4.92
e. 4.97 - ANSWER d. 4.92




Which is necessary for a process to be spontaneous?
Select one:
a. ΔHsys < 0
b. ΔSsys > 0
c. ΔSsurr < 0
d. ΔSuniv > 0
e. ΔGsys = 0 - ANSWER d. ΔSuniv > 0


As the molar mass of a compound increases, the entropy ______.
Select one:
a. decreases
b. is constant
c. increases - ANSWER c. increases


What is ΔS° for the reaction SO2(s) + NO2(g) → SO3(g) + NO(g)?
Substance


S°(J/K • mol)


SO2(g)


248.5


SO3(g)

, 256.2



NO(g)


210.6


NO2(g)


240.5


Select one:
a. 53.6 J/K • mol
b. -53.6 J/K • mol
c. -22.2 J/K • mol
d. 474.8 J/K • mol
e. -474.8 J/K • mol - ANSWER c. -22.2 J/K • mol


The most probable state is the one with the _______.
Select one:
a. highest energy
b. largest number of possible arrangements
c. lowest number of possible arrangements
d. most symmetry
e. highest enthalpy - ANSWER b. largest number of possible arrangements


What is ΔS° for the reaction SO3(g) + H2O(l) → H2SO4(aq)?