<u>Given information:</u>
Concentration of NaF = 0.10 M
Ka of HF = 6.8*10⁻⁴
<u>To determine:</u>
pH of 0.1 M NaF
<u>Explanation:</u>
NaF (aq) ↔ Na+ (aq) + F-(aq)
[Na+] = [F-] = 0.10 M
F- will then react with water in the solution as follows:
F- + H2O ↔ HF + OH-
Kb = [OH-][HF]/[F-]
Kw/Ka = [OH-][HF]/[F-]
At equilibrium: [OH-]=[HF] = x and [F-] = 0.1 - x
10⁻¹⁴/6.8*10⁻⁴ = x²/0.1-x
x = [OH-] = 1.21*10⁻⁶ M
pOH = -log[OH-] = -log[1.21*10⁻⁶] = 5.92
pH = 14 - pOH = 14-5.92 = 8.08
Ans: (b)
pH of 0.10 M NaF is 8.08
To calculate the amount of heat transferred when an amount of reactant is decomposed, we must look at the balanced reaction and its corresponding heat of reaction. In this case, we can see that 252.8 kJ of heat is transferred per 2 moles of CH3OH used. When 22 g of CH3OH is used, 86.9 kJ is absorbed.
Answer:
NH3 has greater water solubility due to intermoleculate interactions
Explanation:
Hi:
If we represent the structures of NH3 and SbH3 we can see that they are similar to the naked eye, this is because N and Sb belong to the same group of the periodic table (group 15).
However, the electronegativity of N is greater than that of Sb. The NH3 molecule is polar and can form an intermolecular interaction called hydrogen bridge with water.
Sb is less electronegative than N. The SBH3 molecule forms an intermolecular interaction with water called dipole-induced dipole.
The zone with positive charge density of the water molecule (hydrogens) is oriented towards the zone with positive charge density of SBH3 (the pair of electrons not shared)
Stronger intermolecular junctions allow greater solubility of NH3 molecules.
Successes in your homework
Answer:
Atmosphere.
Explanation:
Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.
