Answer:
900 J/mol
Explanation:
Data provided:
Enthalpy of the pure liquid at 75° C = 100 J/mol
Enthalpy of the pure vapor at 75° C = 1000 J/mol
Now,
the heat of vaporization is the the change in enthalpy from the liquid state to the vapor stage.
Thus, mathematically,
The heat of vaporization at 75° C
= Enthalpy of the pure vapor at 75° C - Enthalpy of the pure liquid at 75° C
on substituting the values, we get
The heat of vaporization at 75° C = 1000 J/mol - 100 J/mol
or
The heat of vaporization at 75° C = 900 J/mol
Answer: The tree died 9709.46 years before.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
a) to find rate constant
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) to know the age
The tree died 9709.46 years before.
Answer:
The vegetable oils are liquid at room temperature. They contain double bonds. During hydrogenation double bonds break hydrogen is introduced and form vegetable ghee.
Explanation:
Hydrogenation:
It is the chemical process in which hydrogen is introduced in unsaturated hydrocarbons in the presence of catalyst Ni.
Simple hydrogenation reaction:
H₂C = CH₂ + H₂ → CH₃-CH₃
Ni
Hydrogenation is used on industrial level in the production of vegetable ghee.
The unsaturated hydrocarbons, fatty acids undergoes hydrogenation and form ghee.
The vegetable oils are liquid at room temperature. They contain double bonds. During hydrogenation double bonds break hydrogen is introduced and form vegetable ghee.
About 4. the weight of He is about 4 amus and the weight of O is about 16 amus, so you would need 4 He atoms to get close to the same mass as an O atom. i hope this helps
