Answer:
Chemistry definition: Concentration Definition. In chemistry, concentration refers to the amount of a substance per defined space. Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration usually is expressed in terms of mass per unit volume.
Dictionary Definition: the action or power of focusing one's attention or mental effort
Answer:
0.156mol
Explanation:
Number of moles of a substance can be calculated from its mass by dividing its mass by molar mass i.e.
Number of moles (n) = mass/molar mass
Molar mass of PbCl4 is as follows, where Pb = 207.2g/mol, Cl = 35.5g/lol
PbCl4 = 207.2 + 35.5(4)
= 207.2 + 142
= 349.2g/mol
Using: mole = mass/molar mass
mole = 54.32 grams ÷ 349.2g/mol
mole = 0.1555
mole = 0.156mol
Answer : The solubility of
in water is, 
Explanation :
The solubility equilibrium reaction will be:

Let the molar solubility be 's'.
The expression for solubility constant for this reaction will be,
![K_{sp}=[Ag^{+}]^3[PO_4^{3-}]](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BAg%5E%7B%2B%7D%5D%5E3%5BPO_4%5E%7B3-%7D%5D)


Given:
= 
Now put all the given values in the above expression, we get:



Therefore, the solubility of
in water is, 
Explanation:
This process ensures that the pressure inside of the graduated cylinder is the same as the atmospheric pressure in the room.
Suppose the level of water inside and outside the cylinder is same, pressure stays the same. Therefore, total pressure of the is made equal to atmospheric pressure by adjusting the height of cylinder. it is done till the water level is equal.