Answers
Answer:
226.2 kJ/mol
Explanation:
Let's consider the following thermochemical equation for the combustion of acetylene.
C₂H₂(g) + (5/2) O₂(g) → 2 CO₂(g) + H₂O(l), ΔH°rxn = –1299 kJ/mol.
We can also calculate the enthalpy of the reaction per mole of acetylene from the enthalpies of formation.
ΔH°rxn = 2 mol × ΔH°f(CO₂(g)) + 1 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(C₂H₂(g)) - 1 mol × ΔH°f(O₂(g))
1 mol × ΔH°f(C₂H₂(g)) = 2 mol × ΔH°f(CO₂(g)) + 1 mol × ΔH°f(H₂O(l)) - ΔH°rxn - 1 mol × ΔH°f(O₂(g))
1 mol × ΔH°f(C₂H₂(g)) = 2 mol × (-393.5 kJ/mol) + 1 mol × (-285.8 kJ/mol) - (-1299 kJ) - 1 mol × (0 kJ/mol)
ΔH°f(C₂H₂(g)) = 226.2 kJ/mol
Answer:
The enthalpy of formation of acetylene is 226.2 kJ/mol
Explanation:
Step 1: Data given
C2H2 (g) + (5/2)O2 (g) → 2CO2 (g) + H2O (l) Heat of Reaction (Rxn) = -1299kJ/mol
Standard formation [CO2 (g)]= -393.5 kJ/mol
Standard formation [H2O (l)] = -285.8 kj/mol
Step 2: The balanced equation
The formation of acetylene is:
2C(s) + H2(g) → C2H2(g)
Step 3: Calculate the enthalpy of formation of acetylene
It doesn't matter if the process will happen in 1 step or in more steps. What matters is the final result. This is Hess' law of heat summation.
To have the reaction of the formation of acetylene we have to take:
⇒ the reverse equation of the combustion of acetylene
2CO2 (g) + H2O (l) → C2H2 (g) + (5/2)O2 (g)
⇒ The equation of formation of CO2 (multiplied by 2)
2C(s) + 2O2(g) → 2CO2(g)
⇒ the equation of formation of H2O
H2(g) + 1/2 O2(g) → H2O(l)
2CO2 (g) + H2O (l) + 2C(s) + 2O2(g) + H2(g) + 1/2 O2(g → C2H2 (g) + (5/2)O2 (g) + 2CO2(g) + H2O(l)
Final reaction = 2C(s) + H2(g) → C2H2(g)
Calculate the enthalpy of formation of acetylene =
ΔHf = 1299 kJ/mol + (2*-393.5) kJ/mol + (-285.8) kJ/mol
ΔHf = 226.2 kJ/mol
The enthalpy of formation of acetylene is 226.2 kJ/mol
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A chemist titrates 160.0mL of a 0.3403M aniline C6H5NH2 solution with 0.0501M HNO3 solution at 25°C . Calculate the pH at equivalence. The pKb of aniline is 4.87 . Round your answer to 2 decimal places. Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of HNO3 solution added.
Answers
Answer:
Draw the predominant product(s) of the following reactions including stereochemistry when it is appropriate.
CH3CH2 C C CH3 H2O/H2SO4/HgSO4
Explanation:
The given compound is: pent-2-yne.
When it reacts with water, in presence of sulphuric acid and mercuric sulphate then a ketone is formed as shown below:
This reaction is an example of nucleophilic attack of water on carbon carbon triple bond.
The general mechanism of the reaction is hsown below:
Pent-2-yne reacts with water and form 3-pentanone.
The reaction is shown below:
Final answer:
The reaction is the hydration of an alkene in an acidic environment, resulting in the formation of 2-butanol. This result is in accordance with Markovnikov's rule, which determines the position of the hydroxyl group in the resultant product.
Explanation:
The question refers to the acidity-catalyzed hydration of an alkene. In this case, you have an alkene CH3CH2 - CC - CH3 reacting in an acidic environment with water (H2O). The reactants have been exposed to H2O/H2SO4/HgSO4. In this reaction scenario, the acidic medium (H2SO4) and the water enact the role of a nucleophile and attack the alkene, thereby hydrating it.
The product of this reaction will be 2-butanol. Its formation is guided by Markovnikov's rule, which states that in the addition of a protic acid HX to an alkene, the acid hydrogen (H) becomes attached to the carbon with fewer alkyl substituents, and the halide (X) group becomes attached to the carbon with more alkyl substituents. This rule is why the hydroxyl group (-OH) attaches itself to the 2nd carbon atom in the major (predominant) product.
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Answers
Answer: The balanced chemical equation for the reaction of phosphorus trichloride with water is written below.
Explanation:
A balanced chemical equation is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
The balanced chemical equation for the reaction of phosphorus trichloride with water follows:
By Stoichiometry of the reaction:
1 mole of liquid phosphorus trichloride reacts with 3 moles of water to produce 1 mole of aqueous phosphorus acid and 3 moles of aqueous hydrochloric acid.
Hence, the balanced chemical equation for the reaction of phosphorus trichloride with water is written above.
Hey there!:
I'll balance it:
PCl3 + H2O ---> H3PO3 + HCl
* PCl3 (l )+ 3 H2O (l)--->H3PO3(aq) +3 HCl(aq)
Hope that helps!
slow down and move closer together.
merge together to form fewer atoms.
speed up and move further apart.
Answers
Answers
The wavelength of the green light radiation that has a frequency of 6.26 x 10¹⁴ Hz is 4.8 x 10⁻⁷.
What is wavelength?
Wavelength is defined as the distance between identical points or adjacent crests in the adjacent cycles of a waveform signal propagated in the space or wires.
Frequency is defined as the number of waves that passes a fixed place in a given amount of time.
It is also defined as how often something repeats.
As, c = ∧ v
So, ∧ = c / v
∧ = 3.00 x 10⁸ / 6.26 x 10¹⁴
∧ = 4.8 x 10⁻⁷
Thus, the wavelength of the green light radiation that has a frequency of 6.26 x 10¹⁴ Hz is 4.8 x 10⁻⁷.
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So,
λ=(3.00 x 10^8)/(6.26 x 10^14)
Answer= 0.48 x 10^-7
Answers
Answer:
C) Both
Explanation:
Whenever we mix any pure form of a compound with some other form of a compound which is not in the other standard pure state, this results in the melting point of mixture to get dispersed and it becomes broad form.
Thus, when a known compound of 3-Nitroaniline mixes with both 3-Nitroaniline and 4-Nitrophenol, the melting point of the compound becomes depressed and board.
Thus the correct option is (C).
Answers
Answer:
Atom is made up of NUCLEUS and electrons revolving around nucleus.
Nucleus itself contains protons and neutrons. Protons and neutrons are approximately 1680 times heavier than the electrons. So the major contribution to the mass of an atom comes from the nucleus.
Final answer:
The mass of an atom is mostly carried by the nucleons, protons, and neutrons, in its nucleus. Electrons contribute very little to the overall mass of an atom because of their small mass.
Explanation:
Essentially, all of the mass of an atom is due to the nucleons. An atom is primarily composed of protons, neutrons, and electrons. However, the mass of an electron is so small that it contributes very little to the overall mass of an atom. The term 'nucleons' refers to the particles in the nucleus of an atom, namely the protons and neutrons. These particles carry most of the atom's mass given their relatively large mass compared to electrons.
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