Answer:
W = -10.3 kJ
Explanation:
During combustion, the system performs work and releases heat. Therefore, the change in internal energy is negative, and the change in enthalpy, which is equal to heat at constant pressure, is also negative. Work is then calculated by rearranging the equation for the change in internal energy:
w=ΔE−qp=−5084.3 kJ−(−5074.0 kJ)
The release of heat is much greater than the work performed by the system on its surroundings. The potential energy stored in the bonds of octane explains why considerably large amounts of energy can be lost by the system during combustion.
Because you’re body is using energy to keep you alive. Your breathing takes energy, so does your heart beat.
The molar concentration of the KI_3 solution is 0.251 mol/L.
<em>Step 1</em>. Write the <em>balanced chemical equation</em>
I_3^(-) + 2S_2O_3^(2-) → 3I^(-) + S_4O_6^(2-)
<em>Step 2</em>. Calculate the <em>moles of S_2O_3^(2-)</em>
Moles of S_2O_3^(2-)
= 27.9 mL S_2O_3^(2-) ×[0.270 mmol S_2O_3^(2-)/(1 mL S_2O_3^(2-)]
= 7.533 mmol S_2O_3^(2-)
<em>Step 3</em>. Calculate the <em>moles of I_3^(-)
</em>
Moles of I_3^(-) = 7.533 mmol S_2O_3^(2-)))) × [1 mmol I_3^(-)/(2 mmol S_2O_3^(2-)] = 3.766 mmol I_3^(-)
<em>Step 4</em>. Calculate the <em>molar concentration of the I_3^(-)
</em>
<em>c</em> = "moles"/"litres" = 3.766 mmol/15.0 mL = 0.251 mol/L
That would be the NOBLE GASES (Helium, Neon, Argon, Krypton, Xenon, Radon). Because these elements have a filled outer shell (thus giving them the full octet that other elements crave), they are stable elements under normal circumstances and as such resist chemical combination.
Plz note that under special conditions, noble gases such as Xenon and Radon can form compounds (Xenon Fluoride and Oxide; Radon Fluoride)
