When dT = Kf * molality * i
= Kf*m*i
and when molality = (no of moles of solute) / Kg of solvent
= 2.5g /250g x 1 mol /85 g x1000g/kg
=0.1176 molal
and Kf for water = - 1.86 and dT = -0.255
by substitution
0.255 = 1.86* 0.1176 * i
∴ i = 1.166
when the degree of dissociation formula is: when n=2 and i = 1.166
a= i-1/n-1 = (1.166-1)/(2-1) = 0.359 by substitution by a and c(molality) in K formula
∴K = Ca^2/(1-a)
= (0.1176 * 0.359)^2 / (1-0.359)
= 2.8x10^-3
Answer: Option (c) is the correct answer.
Explanation:
A hydrogen bond is defined as a weak bond that is formed between an electropositive atom (generally hydrogen atom) and an electronegative atom like oxygen, nitrogen and fluorine.
An ionic bond is defined as a bond formed between a metal and a non-metal and in this bond transfer of electron takes place from metal to non-metal. And, due to the presence of opposite charges on the combining atoms there exists a strong force of attraction.
Vander waal forces are defined as the weak electric forces which tend to attract neutral molecules towards each other in gases, liquefied and solidified gases.
Vander waal forces are very weak forces.
Thus, we can conclude that Van der walas interactions are weak interactions would require the least amount of energy to disrupt.
Answer:
(d) burning a log.
(b) toasting a slice of bread;
Explanation:
Chemical change -
A chemical change refers to , the change in which a new compound is formed .
From the question ,
Its is not a chemical process , since no new compound is formed , these is only change in state as the liquid is turning to gaseous sate .
It is not a chemical process , as no new substance is formed .
- toasting a slice of bread
It is a chemical change , in which bread surface is deposited by a brown coat via the process of heating , even this process is a irreversible in nature .
It is a chemical change , as with the help of heating , the wood is turning to ashes .
Answer:
a. Polar
b. Polar
c. Non-polar
d. Non-polar
Explanation:
a. 
, hydronium cation contains a positive charge. Just as any other ion, it is polar, as it has a net charge.
b. 
has the same shape as water. There are two lone pairs on sulfur atom which produce an overall dipole moment in this molecule, the bent structure is polar.
c. 
is non-polar, as the central atom, phosphorus, doesn't contain any lone pairs, all the dipole moments cancel out: two dipole moments in the vertical plane, P-Cl, and three P-Cl dipoles in the horizontal plane within a trigonal bipyramidal shape.
d. 
is non-polar, since it's a tetrahedral molecule with no lone pairs on carbon atom, all four C-F dipole moments cancel out to yield a net 0 dipole moment.
Answer:
chemistry - the science that studies the properties of substances and natural fenomens .
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