Answer:
C. number of particles
Explanation:
Entropy is the measure of disorderliness of a system. Remember that when you dissolve salt in water, you increase the number of particles in the solution. The greater the number of particles in solution, the greater the entropy of the solution system.
Hence dissolution of a salt in water increases the entropy by increasing the number of particles in solution leading to the inequality; Ssolution > Swater + Ssalt.
Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles = 
(1)
Number of zinc atoms is equal to 
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,
= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol = 
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
Answer:
At 0.58 L of 0.540 M NaOH solution contain 12.5 g NaOH.
Explanation:
Given data:
At volume = ?
Mass of NaOH = 12.5 g
Molarity of solution = 0.540 M
Solution:
First of all we will calculate the number of moles of sodium hydroxide.
Number of moles = mass/molar mass
Number of moles = 12.5 g / 40 g/mol
Number of moles = 0.3125 mol
Volume of NaOH:
Molarity = number of moles / volume in L
Now we will put the values.
0.540 M = 0.3125 mol / volume in L
volume in L = 0.3125 mol / 0.540 mol/L
volume in L = 0.58 L
Answer:
C. 
Explanation:
Molecules with the stronger intermolecular forces are pulled tightly together to form solid at higher temperatures and that's why the freezing point is higher.
Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.
Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).
Thus, the compound which is gas at room temperature is <u>because it has least number of carbon atoms and absence of hydrogen bonding.</u>
<u></u>
the compounds in which phosphorous posses the highest possible oxidation have to mention here.
The species in which phosphorous have the highest oxidation state are: H₃PO₄, P₂O₅, PCl₅
The possible oxidation state of phosphorous is III and V. The highest oxidation state is V. There are several compounds in which phosphorous posses the +5 oxidation state. Like- Phosphoric acid (H₃PO₄), phosphorous pentoxide (P₂O₅), Phosphorous chloride (PCl₅) etc.
The oxidation state of an element depends upon the valence electron the valence shell of phosphorous is 3s² 3p³. Thus there are 5 electrons, as it has vacant 3d orbital thus it can easily form compound having +5 oxidation state.
