Answer:
The method involves students exhaling air using a plastic straw into the over-titrated acid-base mixture, which turned pink-colored with phenolphthalein indicator.
Answer:
II) Objects made of silver become tarnished.
Explanation:
Physical properties are the properties which can be observed without changing identity of substance.
Chemical properties are the properties which describe how the substance changes into the different substance completely.
Boiling is an example of physical change in state of the substance. Color is also an example of physical property like boiling point and hence these are constants. The reason of the color is that the chromium ions shows certain colors as the electrons are excited due to absorption of the light. The tarnishing of the silver is an example of the chemical change which occurs due to the reaction of the silver with oxygen. This is also known as corrosion.
The ph of a saturated solution of Ca(OH)2 is 12.35
CALCULATION:
For the reaction
Ca(OH)2 → Ca2+ + 2OH-
we will use the Ksp expression to solve for the concentration [OH-] and then use the acid base concepts to get the pH:
Ksp = [Ca2+][OH-]^2
The listed Ksp value is 5.5 x 10^-6. Substituting this to the Ksp expression, we have
Ksp = 5.5 x 10^-6 = (s) (2s)^2 = 4s^3
s3 = 5.5x10^-6 / 4
Taking the cube root, we now have
s = cube root of (5.5x10^-6 / 4)s
= 0.01112
We know that the value of [OH-] is actually equal to 2s:
[OH-] = 2s = 2 * 0.01112 = 0.02224 M
We can now calculate for pOH:
pOH = - log [OH-]
= -log(0.02224)
= 1.65
Therefore, the pH is
pH = 14 - pOH
= 14 - 1.65
= 12.35
Answer:
What do you mean need more details
Explanation:
The answer is B. Equilibrium means a state in which opposing forces or influences are balanced.
