Answer:
ΔH = 53.28 kJ
Explanation:
Solving this kind of problems is quite straight forward. What is need is to manipulate the reactions by multiplying the coefficients and reversing if necessary the reactions so that when we add the reactions together at the end we will arrive to the desired equation we need to obtain the enthalpy.
The reaction we need to calculate the enthalpy is
3C(s) + 3H2(g) → C3H6(g) ΔH = ?
If we take the 2nd reaction and multiply it by three, the inverse of first one multiplied by 1/2 and three times the 3rd we will be get the desired equation and its enthalpy:
3 C(s) + 3 O2(g) → 3 CO₂(g) ΔH= 3 x ( -393.51 kJ)
3 CO₂(g) + 3 H₂O(l) → C₃H₆(g) + 9/2 O₂(g) ΔH= 1/2 x ( 4182.6 kJ)
3 H₂(g) + 3/2 O₂(g) → 3 H₂O(l) ΔH= 3 x ( -285.83 kJ)
3C(s) + 3H2(g) → C3H6(g)
Notice how the mole O2 cancel because they are in diferent sides of the equation. Also we changed the changed of the second since we inverted it.
ΔH = 3 x ( -393.51 kJ) + 1/2 x ( 4182.6 kJ) + 3 x ( -285.83 kJ)
ΔH = - 1180.53 + 2091.3 - 857.49 = 53.28 kJ
Answer:
ΔG° is negative and ΔE° is positive
Explanation:
A galvanic cell produces electrical energy from spontaneous electrochemical processes.
In a galvanic cell, ∆E° is always positive since the reaction is spontaneous at room temperature.
Generally in thermodynamics, a negative value of ∆G shows a spontaneous chemical process. Hence in a galvanic cell, ΔG° is negative and ΔE° is positive.
A molecule of a compound is composed of at least two types of atoms.
Explanation:
A molecule is defined as when two or more atoms of an element combine together by the bonds by sharing the electrons as O^2 (oxygen molecule)
A compound is a molecule when two different types of atom joined by chemical bonds as covalent, ionic or coordinate bonds as NH^3 ( ammonia)
Answer:
Scheme is attached
Explanation:
When 3‑bromopentane reacts with hydroxide, (Z)-pent-2-ene will produce through E 2 (Z)-pent-2-ene.
Mechanism
Hydroxide ion (OH⁻ ) is a strong nucleophile so it abstract the proton from carbon next to the carbon attached with bromine.
The the carbon next to carbon of bromine gets -ve charge, mean while it shares its electrons with the carbon having bromine and make a double bond.
As bromine is a good leaving group so it easily gets detached from carbon, so that carbon comes to its normal state.
As a result (Z)-pent-2-ene will produce. we call it Z because mostly trans products will form.