Answer : The correct answer for change in freezing point = 1.69 ° C
Freezing point depression :
It is defined as depression in freezing point of solvent when volatile or non volatile solute is added .
SO when any solute is added freezing point of solution is less than freezing point of pure solvent . This depression in freezing point is directly proportional to molal concentration of solute .
It can be expressed as :
ΔTf = Freezing point of pure solvent - freezing point of solution = i* kf * m
Where : ΔTf = change in freezing point (°C)
i = Von't Hoff factor
kf =molal freezing point depression constant of solvent.
m = molality of solute (m or 
)
Given : kf = 1.86 
m = 0.907 )
Von't Hoff factor for non volatile solute is always = 1 .Since the sugar is non volatile solute , so i = 1
Plugging value in expression :
ΔTf = 1* 1.86 * 0.907 )
ΔTf = 1.69 ° C
Hence change in freezing point = 1.69 °C
Answer: It will take for the concentration of A to decrease from 0.900 M to 0.210 M is 28.75 s
Explanation:
Zero order reaction : A reaction is said to be of zero order if the rate is independent of the concentration of the reactants, that means the rate is directly proportional to the zeroth power of the concentration of the reactants.
Expression for the zero order kinetics:
![[A]=-kt+[A]_o](https://tex.z-dn.net/?f=%5BA%5D%3D-kt%2B%5BA%5D_o)
where [A] = concentration left after time t = 0.210 M
![[A]_o](https://tex.z-dn.net/?f=%5BA%5D_o)
= initial concentration = 0.900 M
k= rate constant =
t = time for reaction = ?
Thus it will take for the concentration of A to decrease from 0.900 M to 0.210 M is 28.75 s
Nuclear Fusion.
Having low atomic nuclei is the reason why uranium-235 is not commonly found in large nuclear reactions.
So, scientist increases its concentration by fusing the lower atomic nuclei with high atomic nuclei in order to produce a heavier nucleus which will increase the release of energy.
Answer:
NO.3) Mass of Al2O3 formed = 229.5g
Sugar burns and turns black. A completely new substance was formed, which is the main pointer for it being a chemical reaction. More evidence would be change of color, odor, and the fact that flammability is a chemical property so setting something on fire would be a chemical change.
