Answer: A mass of 0.518 g of phenol must be dissolved in 25.0 g of naphthalene to produce a solution that is 0.22 m in phenol.
Explanation:
Given: Mass of naphthalene = 25.0 g
Molality = 0.22 m
This means that 0.22 moles of solute is present per kg of solvent.
As 25.0 g of naphthalene is there that will be 25.0 g per 1000 g (1 kg) is equal to 0.025 kg.
Hence, moles of phenol are calculated as follows.
Also, molar mass of phenol is 94.11 g/mol. This means that 1 mole of phenol contains 94.11 g.
Therefore, mass contained by 0.0055 moles of phenol is as follows.
Thus, we can conclude that a mass of 0.518 g of phenol must be dissolved in 25.0 g of naphthalene to produce a solution that is 0.22 m in phenol.
Answer:this is the answer
Explanation:
A 0.50 M solution of a monoprotic acid HA with a pH of 2.24 would be, first, a weak acid, as it does not dissociate fully. This leaves us with an equilibrium expression: HA (aq) <span>⇌ H+ (aq) + A- (aq)
Where A- is the conjugate base of the weak acid.
In a study of equilibrium, we remember that the ka value is the acid dissociation constant, and has the equation:
Ka = (concentration of H+)(concentration of conjugate base)/concentration of acid
We know the concentration of H+ and A- are 10^-2.24 by the definition of a pH being the -log(concentration of H+).
The concentration of the acid has gone down a little bit, as it has partially dissociated into H+ and A-, so we'll have to subtract 10^-2.24 from 0.50 for the concentration of the acid to account for the dissociation.
The final equation would then become:
[H+]*[A-]/[HA] = Ka
(10^-2.24) * (10^-2.24) / (0.50 - 10^-2.24) = Ka
(3.31 * 10^-5) / (0.494) = Ka
Ka = 6.70 * 10^-5</span>
The answer is: gas
- First, we have to understand the 4 state of matter:
1) Solids: The molecular or ionic attracts each other by intermolecular forces. They connect with each other by strong convalent bonds that are hard to be broken in normal conditions. The heat energy is used to go through the weak intermolecular forces, So in a normal case, the solids usually have a stable shape.
2) Liquid: Unlike gases, It will take the container shape, and haven't the ability to change its volume to fill a container The intermolecular bonding is helping to give liquid its certain volume. Liquid able to flow and take any shape according to the container shape. The molecules of the liquid are closed together that is why it is hard to compress, the only high pressure will be able to compress it a little.
3)Gases: gases move rapidly in a straight line until it hit an object like the wall of the container then start to move with an aimless direction in a random way called random walk and unlike liquids, it can be compressed.
4) plasma: is unlike the gases, liquid and solid. It does not exist normally on the earth but we have to generate it from neutral gases.It has a neutral charge.
The last set which is n=4 l=3 m=3 is a valid set