TERM TEST

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TERM TEST 2
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1. In an exothermic reaction the (A) reactants
have less energy than the products since
energy is absorbed from the surroundings (B)
products have more stored energy than the
reactants (C) reactants and produces have the
same amount of stored energy (D) reactants
have more scored energy than the products
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2. Which of the following sources of
energy is the MOST commonly used in the world
today? (A) Nuclear (B) Fossil fuels (C) Biogas (D)
Gasohol
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3.. Study the following thermochemical
equation. X Y Z, ? H - B kJ Which of the
following methods can be used to compute the
value of - B kJ? I. Energy of Z minus the
energy of X and Y II. Energy of X and Y
minus the energy of Z III The
sum of the energies of X, Y and Z (A) I
only (B) I and II only (C) III only (D) II and
III only
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4. Which of the following statements about
chemical reactions is NOT correct? (A)
Energy is given out when bonds break and taken in
when bonds form. (B) Chemical reactions
involve the making and breaking of bonds. (C)
Endothermic reactions take energy from the
surroundings. (D) Exothermic reactions give
energy to the surroundings.
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5. When crystals of potassium nitrate are
dissolved in water, the temperature of the
solution decreases because (A) little
energy is required to break down the crystal
structure of the potassium nitrate (B) heat
is always absorbed when a substance dissolves (C)
the energy content of dissolved potassium
nitrate is higher than that of solid potassium
nitrate (D) potassium nitrate is colder
than water
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6. The condensation of Steam is an exo-
.thermic reaction. Which of the following would
therefore be true? I
Heat is absorbed II Heat is evolved
III ?H is negative IV ?H is
positive A. I only B. II and III only C. I
and IV only D. I, II, III and IV
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• A catalyst increases the rate of a reaction it
• (A) weakens the bonds in the reactants
• (B) provides an alternative route of
  higher activation energy
• (C) provides an alternative route of
• lower activation energy
• (D) binds irreversibly with the reactants

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8.. Which of the following is true about
the rate of a reaction? (A) It increases us the
reaction proceeds. (B) It increases as the
pressure in gases decreases(C) It
decreases if the kinetic energy of the reacting
particles decreases. (D) It decreases if the
reacting particles are more finely divided.
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• 9. When heat is given off to the surroundings
  during a chemical reaction, it is because bond
  breaking
• and bond making release energy
• requires less energy than that released when
  new bonds are formed
• (C) requires more energy than that released
  when new bonds are formed
• (D) is an endothermic process whereas bond
  making is an exothermic one

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10. Which of the following factors may NOT
affect the rate of some chemical
reactions? (A) Pressure (B) Temperature (C) Ca
talyst (D) Concentration