Depression in freezing point (Δ

) =

×m×i,
where,

= cryoscopic constant =

,
m= molality of solution = 0.0085 m
i = van't Hoff factor = 2 (For

)
Thus, (Δ

) = 1.86 X 0.0085 X 2 =

Now, (Δ

) =

- T
Here, T = freezing point of solution

= freezing point of solvent =

Thus, T =

- (Δ

) = -
Answer:
It has two isomers; n-butane and isobutane. Here n-butane is a straight-chain compound with four carbon atoms bonded with single covalent bonds. Explanation: Butane is an alkane with four carbon atoms so molecular formula is C4H10.
Explanation:
Answer: The correct option is 1.
Explanation: Endothermic reactions are the reactions in which heat is provided to break down the reactant molecules.
In option 1:
The stronger intermolecular forces between the particles in solid molecule are broken down to convert into gaseous form. Hence, some energy in the form of heat is provided to move them far apart. Therefore, it is considered as an endothermic reaction.
In option 2, 3 and 4:
All the other processes involves the formation of bonds and thus there is no need to provide any energy.
It showed that the nucleus is positively charged, and that the atom isn't just made of electrons.
Answer:
Density is mass over volume.
Explanation: