Answer:
35.453 atomic mass units
You can use Phet (Atomic masses, Elements and more) for Chemistry
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:
Chemical changes
Explanation:
a)Burning a piece of charcoal - chemical change
b) Heating copper (ii) carbonate strongly - chemical change
c) Heating Zinc oxide strongly - chemical change
The given types of reaction indicates chemical changes. A chemical change is one in which a new kind of matter is formed. It is always accompanied by energy changes. The process is not easily reversible and hence, it is a permanent procedure.
Burning of charcoal produces a new kind of produces in the combustion process.
Both heating of copper(ii)carbonate strongly and zinc oxide will lead to a decomposition reaction in which new compounds are formed.
Answer:
3)Some gas molecules move further apart and some move closer together.
Explanation:
because When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed. The particles exert more force on the interior volume of the container. This force is called pressure. There are several units used to express pressure.
