Circle the best answer for each of the following questions.

1		The scientist who discovered oxygen was
			A)	Joseph Priestley
			B)	Johann Becher
			C)	Fritz Haber
			D)	Antoine Lavoisier
2		According to the phlogiston hypothesis,
			A)	all substances that can be burned contain phlogiston
			B)	as a substance burns, the phlogiston it contains is turned into ash or powder
			C)	metals are considered to be solid forms of pure phlogiston
			D)	phlogiston must be present in air before a substance can be burned
3		The phlogiston hypothesis was overthrown as a result of the experiments conducted by
			A)	Georg Stahl
			B)	Joseph Priestley
			C)	Antoine Lavoisier
			D)	Johann Becher
4		When heated in the presence of air, tin turns into a white powder. The substance in the air that combines with the tin to form the white powder is
			A)	nitrogen
			B)	hydrogen
			C)	carbon dioxide
			D)	oxygen
5		In the preceding question, the tin has been
			A)	activated
			B)	oxidized
			C)	tempered
			D)	alloyed
6		The burning of coal, in which energy is liberated, is a(n)
			A)	exothermic reaction
			B)	endothermic reaction
			C)	catalytic reaction
			D)	equilibrium reaction
7		A compound is usually relatively stable if
			A)	its decomposition is weakly exothermic
			B)	it liberates energy when decomposed
			C)	a great deal of energy is needed to decompose the compound
			D)	the PE of its electrons is high
8		A good fuel is
			A)	strongly exothermic
			B)	cheap and abundant
			C)	easy to transport
			D)	all of the above
9		A catalytic converter works by
			A)	trapping harmful gases so they are not part of the exhaust
			B)	increasing the reaction temperature to increase the rate of combustion
			C)	increasing the concentration of exhaust gas to promote more complete combustion
			D)	promoting reactions that convert polluting gases into harmless ones by the actions of certain metals
10		Hydrogen is not widely used as a fuel at present because
			A)	its combustion products are extremely "dirty"
			B)	it is currently too expensive for ordinary purposes
			C)	it has an extremely low heat of combustion
			D)	it is scarce
11		A disadvantage of the use of syngas is
			A)	the scarcity of the raw materials needed to produce syngas
			B)	its high sulfur content
			C)	problems related to transport and storage
			D)	its carbon monoxide content
12		Which one of the following elements plays a major role in the formation of acid rain?
			A)	carbon
			B)	sulfur
			C)	chlorine
			D)	boron
13		The rate of a chemical reaction can be increased by
			A)	lowering the temperature of the reaction
			B)	reducing the concentration of the reactants
			C)	increasing the surface area of a solid reactant
			D)	lowering the activation energy
14		Catalysts used by living organisms to regulate their chemical processes are called
			A)	hormones
			B)	steroids
			C)	enzymes
			D)	lipids
15		A major disadvantage of fuel cells is their
			A)	relatively short life span
			B)	high weight in proportion to the electrical power they supply
			C)	lower efficiency as compared to current lead-acid storage batteries
			D)	greater expense as compared to current lead-acid batteries

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16		The drawing represents
			A)	combustion of molten NaCl
			B)	transmutation of NaCl
			C)	catalytic dissociation of NaCl
			D)	electrolysis of molten NaCl
17		The current in the molten NaCl consists of
			A)	moving Na and Cl atoms
			B)	moving Na+ and Cl– ions
			C)	moving Cl– ions only
			D)	moving electrons
18		The process illustrated by the drawing is an example of
			A)	an oxidation reaction only
			B)	a reduction reaction only
			C)	both oxidation and reduction reactions
			D)	an acid-base neutralization reaction

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19		The nitrate ions (NO3–) remain in solution because
			A)	nitrate ions are more soluble than silver ions
			B)	silver atoms lose electrons at the anode more readily than nitrate ions
			C)	the mass of a nitrate ion is less than that of a silver ion
			D)	silver ions have a greater tendency to react with the metals than do nitrate ions
20		Silver atoms are reduced at the
			A)	spoon
			B)	anode
			C)	battery
			D)	cathode