Answer:
True => ΔH°f for C₆H₆ = 49 Kj/mole
Explanation:
See Thermodynamic Properties Table in appendix of most college level general chemistry texts. The values shown are for the standard heat of formation of substances at 25°C. The Standard Heat of Formation of a substance - by definition - is the amount of heat energy gained or lost on formation of the substance from its basic elements in their standard state. C₆H₆(l) is formed from Carbon and Hydrogen in their basic standard states. All elements in their basic standard states have ΔH°f values equal to zero Kj/mole.
<span>Answer: option D) Conditions over the oceans change slowly because water takes more time than land to gain or lose heat.
This is because water has a high heat capacity meaning that, with the same amount of heat, it will change its temperature less than what substances with lower heat capacities do.
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(NH4)3PO4 :
N = 14 * 3 = 42
H = 1 * 12 = 12
P = 31 * 1 = 31
O = 16 * 4 = 64
-------------------------
42+12+31+64 = 149 g / mol
Hope this helps!.
Answer:
Kc = 0.20
Explanation:
N₂O₄ ⇄ 2NO₂
moles 5.3mol 2.3mol
Vol 5L 5L
Molarity 5.3/5M 2.3/5M
= 1.06M = 0.46M
Kc = [NO₂]²/[N₂O₄] = (0.46)²/(1.06) = 0.1996 ≅ 0.20