Chemestry help?

2017-06-09 12:22 pm

Which statement is true concerning this reaction:
2SO3(g) ® 2SO2(g) + O2(g)rH = +198 kJ
a. The reaction is exothermic
b. The reaction container would feel warm.
c. 198 kJ are given off as 2.00g of SO3 react.
d. 198 kJ are needed to produce 2.00 mol of SO2.

And

Which statement concerning these equations is correct?
(1) K(s) + 1/2Br2(l) ® KBr(s)rH = -394 kJ
(2) K(s) + 1/2Br2(g) ® KBr(s)rH = -416 kJ
a. Both reactions are endothermic.
b. For each mole of KBr(s) formed in reaction (2), 416 kJ of heat is absorbed.
c. If reaction (1) occurs in an insulated container, the temperature in the container will rise.
d. In both reactions, the heat content of the KBr(s) is more
than that of the reactants.

回答 (1)

micatkie

2017-06-09 5:49 pm

✔ 最佳答案

1.
a. False
The positive ΔH indicates that the reaction is endothermic.

b. False
The reaction container would feel cold for an endothermic reaction.

c. False
Heat is absorbed when the reaction is endothermic.

d. True
Refer to the thermochemical equation.

The answer: d. 198 kJ are needed to produce 2.00 mol of SO2.

====
2.
a. False
The two negative ΔH values indicate that both reaction are exothermic.

b. False
416 kJ of heat is released.

c. True
The heat released from the reaction makes the temperature rise.

d. False
The heat content of the KBr(s) is less than that of the reactants. When the heat content decreases, heat is released.

The answer: c. If reaction (1) occurs in an insulated container, the temperature in the container will rise.

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