Answer:If we dissolve NaF in water, we get the following equilibrium:
text{F}^-(aq)+text{H}_2text{O}(l) rightleftarrows text{HF}(aq)+text{OH}^-(aq)
The pH of the resulting solution can be determined if the K_b of the fluoride ion is known.
20.0 g of sodium fluoride is dissolve in enough water to make 500.0 mL of solution. Calculate the pH of the solution. The K_b of the fluoride ion is 1.4 × 10 −11 .
Step 1: List the known values and plan the problem.
Known
mass NaF = 20.0 g
molar mass NaF = 41.99 g/mol
volume solution = 0.500 L
K_b of F – = 1.4 × 10 −11
Unknown
pH of solution = ?
The molarity of the F − solution can be calculated from the mass, molar mass, and solution volume. Since NaF completely dissociates, the molarity of the NaF is equal to the molarity of the F − ion. An ICE Table (below) can be used to calculate the concentration of OH − produced and then the pH of the solution.
Explanation:
Answer:
A. One unpaired electron
B. 5 unpaired electrons
Explanation:
In A ,Fe is in +3 oxidation state and Electronic configuration- [Ar]3d5
And NO2 is a strong field ligand hence it causes pairing in t2g orbitals and results one unpaired electron in dZX orbital.
In B, also Fe is in +3 oxidation state but F is weak field ligand hence causes no pairing of Electrons hence it results 5 unpaired electrons with electronic configuration t2g^3 eg^2
Answer & Explanation:
The law of multiple proportion states that two elements A and B can react with each other to form multiple compounds while one of the two elements remain fixed.
For Example
Hydrogen reacts with oxygen to form:
Water (H2O)
Hydrogen peroxide (H2O2)
Answer:
Explanation: It has been given that the temperature of the water decreases when chromium chloride is dissolved in water. Thus fall in the temperature explains the fact that the bond energies of the reactants have more energy rather than the products.
a) Thus the heat of the solution is endothermic in nature as more energy is needed to break the reactant molecules.
b) The combined ionic bond strength of CrCl2 and inter molecular forces between water molecules must be stronger than the attractive forces between the water molecules and chromium and chloride ions as the reaction is endothermic in nature thus more energy would be required to break the bonds between the reactants hence making them more stronger.
