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amm1812
3 years ago
12

5. For which of the following reactions would the heat of reaction be labelled ∆Hf°? a) PCl3 + ½ O2(g) ->POCl3(g) b) CaO(s) +

SO2(g) -> CaSO3(s) c) Al(s) + 3/2O2(g) + 3/2H2(g) -> Al(OH)3(s) d) ½ N2O(g) + 1/4 O2(g) -> NO(g)
Chemistry
1 answer:
user100 [1]3 years ago
8 0

Answer:

C

Explanation:

∆H°f means the enthalpy change of formation of one mole of substance by its constituent elements under standard conditions.

So in an equation for ∆H°f, we must see 2 or more elements as reactants combining to form a compound.

In the 4 answers, only C represents elements forming a substance (Al(s) + 3/2O2(g) + 3/2H2(g) -> Al(OH)3(s)),

while the others include compounds as one of their reactants.

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D (The last answer)

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19) The nuclear symbol of helium,
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Alpha particle

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4 0
3 years ago
If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 K and then I raise the pressu
mixas84 [53]

Answer:

The answer to your question is V2 = 29.6 l

Explanation:

Data

Pressure 1 = P1 = 12 atm

Volume 1 = V1 = 23 l

Temperature 1 = T1 = 200 °K

Pressure 2 = 14 atm

Volume 2 = V2 = =

Temperature 2 = T2 = 300°K

Process

1.- To solve this problem use the Combine gas law.

             P1V1/T1 = P2V2/T2

-Solve for V2

             V2 = P1V1T2 / T1P2

2.- Substitution

             V2 = (12)(23)(300) / (200)(14)

3.- Simplification

             V2 = 82800 / 2800

4.- Result

            V2 = 29.6 l

5 0
3 years ago
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