D) tetrahedral
E) T-shaped
5) Sodium hydride reacts with excess water to produce aqueous sodium hydroxide and
hydrogen gas:
NaH (s) + H2O (l) → NaOH (aq) + H2 (g)
A sample of NaH weighing ________ g will produce 982 mL of gas at 28.0 °C and 765
torr, when the hydrogen is collected over water. The vapor pressure of water at this
temperature is 28 torr.
A) 2.93
B) 0.960
C) 0.925
D) 0.0388
E) 925
6) What is the mass % of oxygen in lead (II) nitrate (Pb(NO3)2) rounded to three
significant figures?
A) 4.83
B) 19.3
C) 29.0
D) 14.5
E) 0.331
7) In general, as activation energy increases, reaction rate ________.
A) goes down if the reaction is exothermic
B) goes down if the reaction is endothermic
C) stays the same regardless of whether the reaction is exothermic or endothermic
D) goes down regardless of whether the reaction is exothermic or endothermic
E) none of the above
8) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: