Barrons SAT Subject Test Chemistry, 13th Edition

(D) 2.0 × 10−5

(E) 3.0 × 10−10

45. 
    

    If the density of a diatomic gas at STP is 1.43 grams/liter, what is the molar
    mass of the gas?
    (A) 14.3 g
    (B) 32.0 g
    (C) 48.0 g
    (D) 64.3 g
    (E) 224 g

    
    


46. 
    

    From 2 moles of KClO 3 how many liters of O 2 can be produced at STP by

    
    

decomposition of all the KClO 3?

(A) 11.2

(B) 22.4

(C) 33.6

(D) 44.8

(E) 67.2

47. Which value best determines whether a reaction is spontaneous?

(A) change in Gibbs free energy, ΔG

(B) change in entropy, ΔS

(C) change in kinetic energy, ΔKE

(D) change in enthalpy, ΔH

(E) change in potential energy, ΔPE

Questions 48–52 refer to the following experimental scenario and data:

Silver oxide is placed into a crucible and heated strongly for 15 minutes over a
flame. After cooling, the mass of the crucible and contents is determined. The
whole system is heated strongly again for 5 minutes and cooled. Then the mass is
measured again.

Recorded Data:

Mass of crucible

= 14.03 g

Mass of crucible and silver oxide

= 18.67 g

Mass of crucible and product (after 1st heating)

= 18.36 g