Answer:
25.7 kJ/mol
Explanation:
There are two heats involved.
heat of solution of NH₄NO₃ + heat from water = 0
q₁ + q₂ = 0
n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃
∴ n = 0.100 mol NH₄NO₃
q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln
m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g
q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J
q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0
ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol
<span>As mentioned, the isomerization of cyclopropane to propylene is a first-order process with a half-life of 19 min at 500°c. A first-order reaction kinetic rates means that the rate is constant throughout the reaction.
Thus, the time it takes for the partial pressure of cyclopropane to decrease from 1 atm to 0.125 atm at 500°c is </span><span>57 minutes.</span>
<h2>The answer is option b "free energy is zero"</h2>
Explanation
- The reaction that has negative free energy are called exergonic reactions that means the reactants have more free energy than the product formed.
- The reaction that has positive free energy are called endergonic reactions that means the final state or the products formed have more free energy than the initial state or the reactants.
- The reaction that has zero free energy occurs when the free energy of both reactants and the products are same hence the rate of formation of products and reactants are equal.
- Therefore, when reactants and products are being formed at an equal rate the free energy is zero.
Answer:
ΔS surrounding (entropy change of the reservoir) = -1 J/K
Explanation:
Given:
Change in heat (ΔH) = 150 joules
Temperature (T) = 150 K
Find:
ΔS surrounding (entropy change of the reservoir)
Computation:
ΔS surrounding (entropy change of the reservoir) = - ΔH / T
ΔS surrounding (entropy change of the reservoir) = - 150 / 150
ΔS surrounding (entropy change of the reservoir) = -1 J/K
Answer:
D. the sea of electrons
Explanation:
Metallic bonds are defined as the bonds formed between two or more metals. Silver atom form metallic bond with other silver atoms.
In metallic bond, the free electrons or valence electrons present in s and p orbitals delocalize. The valence electrons do not move around the atoms or enter the atoms whereas they form a sea of electrons in which they surround the nuclei (positively charged) of the metal ions interacting. The valence electrons are then freely move in the space between the atomic nuclei.
Hence, the correct answer is "D. the sea of electrons".
