Alkanes can, the double bonds mean that something can be added across it
Answer:
The change of state of wax from solid to liquid and liquid to vapors is a physical change.
Explanation:
Physical Change
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
.
These changes occur due to chemical reactions.
These may not be observed with naked eye
Example
When a candle is burned, the both physical and chemical changes occur.
The solid wax is melted into the liquid and than liquid is evaporated into vapor form. It is a physical change because just the state of mater is changed. When vapors of wax are react with oxygen in air and form carbon dioxide and ash it is a chemical change which can not be reversed.
Pka = - log ka
10.36 = - log ka
Ka = .......
Answer:
At equilibrium:
[H2] = 0.005 M
[Br2] = 0.105 M
[HBr] = 0.189 M
Explanation:
H2(g) + Br2(g) ⇄ 2HBr
an "x" value will be used from reactant to produced "2x"
so at equilibrium:
[H2] = 0.1 - x
[Br2] = 0.2 - x
[HBr] = 2x
we know that Kc=[HBr]²/[H2][Br2]
Thus 62.5 = (2x)²/(0.1-x)(0.2-x)
this generate a quadratic equation: 58.5x² - 18.75x + 1.25 = 0
the x₁ = 0.23 x₂ = 0.09457
we pick 0.09457 because the two reactants can not make more than what they have. x₁ is higher than both initial reactant concentration
Then we substitute the "x₂" value at equilibrium:
[H2] = 0.1-0.09457 = 0.005 M
[Br2] = 0.2-0.09457 = 0.105 M
[HBr] = 2*0.09457 = 0.189 M
