Answer: a)
: negative
b)
: positive
c)
: positive.
d)
: negative
e)
: positive.
f)
: positive.
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
is positive when randomness increases and
is negative when randomness decreases.
a) 
As ions are moving to solid form , randomness decreases and thus sign of
is negative.
b) 
As solid is changing to gas, randomness increases and thus sign of
is positive.
c) 
As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of
is positive.
d) 
As gas is changing to solid, randomness decreases and thus sign of
is negative.
e) 
As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of
is positive.
f)
As solid is changing to gas, randomness increases and thus sign of
is positive.
Answer:
C. Gain in electron(s) resulting in a decrease of oxidation number.
Explanation:
Redox reactions are reactions involving transfer of of electron between two species (reduction specie) and (oxidation species) and change resulting in change in oxidation number.
Reduction in terms of redox reaction is the specie that accepts electron(s) and gets "reduced" since its oxidation state has been reduced.
For example
Cl + e- → Cl⁻
The above reaction is an example of reduction reaction taking place in a redox reaction. We can see that Chlorine oxidation state was changed from (0) to (-1) state.
Answer:
Compounds are pure substance consisting of two or more different atoms
Answer:
a) IUPAC Names:
1) (<em>trans</em>)-but-2-ene
2) (<em>cis</em>)-but-2-ene
3) but-1-ene
b) Balance Equation:
C₄H₁₀O + H₃PO₄ → C₄H₈ + H₂O + H₃PO₄
As H₃PO₄ is catalyst and remains unchanged so we can also write as,
C₄H₁₀O → C₄H₈ + H₂O
c) Rule:
When more than one alkene products are possible then the one thermodynamically stable is favored. Thermodynamically more substituted alkenes are stable. Furthermore, trans alkenes are more stable than cis alkenes. Hence, in our case the major product is trans alkene followed by cis. The minor alkene is the 1-butene as it is less substituted.
d) C is not Geometrical Isomer:
For any alkene to demonstrate geometrical isomerism it is important that there must be two different geminal substituents attached to both carbon atoms. In 1-butene one carbon has same geminal substituents (i.e H atoms). Hence, it can not give geometrical isomers.