Answer:
7. A) I, II
; 8. D) 2.34e9 kJ
Step-by-step explanation:
7. Combustion of ethanol
I. The negative sign for ΔH shows that the reaction is exothermic.
II. The enthalpy change would be different if gaseous water were produced.
That's because it takes energy to convert liquid water to gaseous water, and this energy is included in the value of ΔH.
III. The reaction is a redox reaction, because
- Oxygen is reacting with a compound
- The oxidation number of C increases
- The oxidation number of O decreases.
IV. The products of the reaction occupy a smaller volume than the reactants, because 3 mol of gaseous reactant are forming 2 mol of gaseous product.
Therefore, only I and II are correct.
7. Hindenburg
Data:
V = 2.00 × 10⁸ L
p = 1.00 atm
T = 25.1 °C
ΔH = -286 kJ·mol⁻¹
Calculations:
(a) Convert temperature to kelvins
T = (25.1 + 273.15) K = 298.25 K
(b) Moles of hydrogen
Use the <em>Ideal Gas Law</em>:
pV = nRT
n = (pV)/(RT)
n = (1.00 × 2.00 × 10⁸)/(0.082 06 × 298.25) = 8.172 × 10⁶ mol
(c) Heat evolved
q = nΔH = 8.172 × 10⁶ × (-286) = -2.34 × 10⁹ kJ
The hydrogen in the Hindenburg released 2.34e9 kJ
.
Answer:
5. 2 Al 3 Cl2 and 2 AlCl3
Cl2 is limiting
(It has the highest coefficients, but that's not always true. If they give you the number of grams for each make sure to work the math out)
6. C
(As the pressure increases there is less volume for the molecules to move around, therefore the molecules will be closer together, allowing for more collisions.)
7. b
(if the temperature is increases so will the rate of the reaction. The increase in temperature will allow for the molecules to move at a faster rate, allowing for more collisions (reactions) between them.
8. d
(dynamic equilibrium is the state at which the reaction is consistently moving, there fore the amounts should remain the same)
9. A
(a catalyst will lower the the pathway of activation energy because it's meant to speed up a reaction)
bro youre on your own after this, im tired
Tollen's test is a test for aldehyde giving a silver mirror in its presence, hence also called silver mirror test. Among the choice, c. pentanal is the aldehyde. Answer is C.
Answer:
Yes
Explanation:
The process of respiration and burning are similar in the following ways: Both respiration and burning require oxygen. Energy is released during both respiration and burning. The products produced (carbon dioxide and water) are the same for both respiration and burning.
