D. ( Neither ultrasonic nor infrasonic vibrations can be heard by humans. )
Answer:
two electrons are lost by magnesium to form magnesium ion (Mn+2) and gained by two oxygen atoms (O-)
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:
The correct answer is option 3.
Explanation:
The expression of 
is given by :
![K_w=[H^+][OH^-]](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BOH%5E-%5D)
![K_w\propto [H^+]](https://tex.z-dn.net/?f=K_w%5Cpropto%20%5BH%5E%2B%5D)
![K_w\propto [OH^-]](https://tex.z-dn.net/?f=K_w%5Cpropto%20%5BOH%5E-%5D)
Rise in temperature will result in more dissociation of water molecules into hydrogen ions and hydroxide ions.
With an increase in concentration of hydrogen ions and hydroxide ions value of will also increase.
Mass measures the amount of matter in an object
