Answers and Explanation:
a)- The chemical equation for the corresponden equilibrium of Ka1 is:
2. HNO2(aq)⇌H+(aq)+NO−2
Because Ka1 correspond to a dissociation equilibrium. Nitrous acid (HNO₂) losses a proton (H⁺) and gives the monovalent anion NO₂⁻.
b)- The relation between Ka and the free energy change (ΔG) is given by the following equation:
ΔG= ΔGº + RT ln Q
Where T is the temperature (T= 25ºc= 298 K) and R is the gases constant (8.314 J/K.mol)
At the equilibrium: ΔG=0 and Q= Ka. So, we can calculate ΔGº by introducing the value of Ka:
⇒ 0 = ΔGº + RT ln Ka
ΔGº= - RT ln Ka
ΔGº= -8.314 J/K.mol x 298 K x ln (4.5 10⁻⁴)
ΔGº= 19092.8 J/mol
c)- According to the previous demonstation, at equilibrium ΔG= 0.
d)- In a non-equilibrium condition, we have Q which is calculated with the concentrations of products and reactions in a non equilibrium state:
ΔG= ΔGº + RT ln Q
Q= ((H⁺) (NO₂⁻))/(HNO₂)
Q= ( (5.9 10⁻² M) x (6.7 10⁻⁴ M) ) / (0.21 M)
Q= 1.88 10⁻⁴
We know that ΔGº= 19092.8 J/mol, so:
ΔG= ΔGº + RT ln Q
ΔG= 19092.8 J/mol + (8.314 J/K.mol x 298 K x ln (1.88 10⁻⁴)
ΔG= -2162.4 J/mol
Notice that ΔG<0, so the process is spontaneous in that direction.
The answer is; D
Enthalpy is the system’s internal energy ( considering the product of its pressure and volume). When the enthalpy is negative, it means that the products have a lower energy level than the reactants - meaning the system has dispensed some energy into the environment.
The double replacement reaction
<h3>Further explanation</h3>
Given
Reaction if Na₂S + HCl
Required
Type of reaction
Solution
The double replacement reaction occurs when there is a displacement of the cations and anions of the reactants involved in the reaction to form two new compounds.
The general formula for this reaction :
AB + CD ⇒ AD + CB
At the bottom of the reaction, it is shown the number of atoms of each compound in the reactants and products which indicates the application of <em>the law of conservation of mass</em>, that the number of atoms in the reactants will be the same as the number of atoms in the product, so the reaction is said to be in a balanced state.
Answer:There are important differences between naturally occurring sugars, ... Understanding these differences can help you make choices that are better for your health. ... of energy, along with a bevy of vitamins, minerals, and phytonutrients. ... sugar substitutes, but many people find they have an unpleasant
Explanation: