Answer: It´s question of resonance
Explanation: I think in case of crystal glass it have
certain structure. There are certain frequencies crystal can vibrate.
High sound frequencies resonate, also give energy to structure vibrations and it vibrates more strongly until structure breaks up.
Answer:
0.0038 M
Explanation:
Hardness of the water is generally due to the presence of 
in water.
At equivalence point
Moles of 
= Moles of EDTA
Considering
Given that:
So,
Answer:
Before the equivalence point, conductivity is decreasing. After the equivalence point, conductivity is increasing
Explanation:
In solution H2SO3 produce H+ ions and SO3²⁻ ions. In the same way, NaOH produce Na⁺ and OH⁻ ions. The conductivity of a solution is directly proportional to the concentration of ions in a solution. During titration, you are adding more NaOH (That is, more Na⁺ and OH⁻ ions). But each moles of OH⁻ reacts with H⁺ ion producing H₂O. That means the moles of Na⁺ that you are adding = Moles of H⁺ are been consumed. The concentration of ions remains approximately constant. But, H⁺ ion conducts better than Na⁺ ion. That means before the equivalence point, conductivity is decreasing. But after the equivalence point you will add OH- ions in excess increasing ion concentration increasing the conductivity:
After equivalence point, conductivity is increasing.
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:
