Answer: The correct answer is option (A).
Explanation:
Polar molecules are molecules in which formation of partial charges takes place due to which dipole moment gets created in a molecule. Molecules with polar bonds that s bond with partly ionic character. And water is of the example of polar molecule.
Electronegative oxygen atom in water molecule attracts the electron bond pair towards itself which generates partial negative charge on oxygen atom and partial positive charge on both hydrogen atoms.
Where as water has higher value surface tension due to strong intermolecular association of the water molecule due to presence of hydrogen bonding.And it is more denser is liquid state than in its solid state.
Hence,the correct answer is option (A).
1st and 4th options are suitable answers, as these 2 changes are not exactly physical changes as it cant return back to original form and as well as its not cooling, so I feel its 1st and 4th options
5.7% KCl is 94.3 % water.
Therefore, for 1000 g of water the mass of KCl will be (1000× 5.7)/94.3 = 60.445 grams.
1 mole of KCl is equal to 74.55 g,
therefore, 60.445 g will be 60.445/74.55 = 0.8108 mole of KCl
Hence, 0.8108 moles of KCl should release twice that number of moles 1.6216 moles ions.
Having 1.6216 moles of KCl ions dissolved in 1000g of water, gives us 1.6216 molar if solution.
Using the freezing point depression constant of water.
dT = Kf (molarity)
dT = (1.86 C/ molar) (1.6216 m)
dT = 3.016 C drop in freezing point
Therefore, it should freeze at - 3.016 Celsius
