Answer:
16%
Explanation:
Crotonic acid : C₃H₅CO₂H
C₃H₅CO₂H ⇄ C₃H₅CO₂⁻ + H⁺
C O O
where : C = C ( 1 - ∝ ) , O = C∝
also: Ka = C∝² / ( 1 - ∝ ) ---- ( 1 )
<em>From Alexa data resource : </em>
Pka = 4.69 , [ Ka = 2.04 * 10^-5 = C∝² / ( 1 - ∝ ) ]
back to equation 1
2.04 * 10^-5 = [ ( 0.63 * 10^-3 ) * ∝² / ( 1 - ∝ ) ] ----- ( 2 )
∴ ∝² / ( 1 - ∝ ) = 3.24 * 10⁻²
Resolving equation above
∝ = 0.1645 = 16.45%
Option c. dendrochronology
tree rings or dendrochronology they allow to use it in calibration for carbon-14 on temporal placements of fragments of wood (from long dead trees).
Example Bristle cone pines (1957) 4723 years old
Because light travels faster than sound
KOH + HBr ---> KBr + H2O
0,3 moles of HBr ---in-------1000ml
x moles of HBr-------in------75ml
x = 0,0225 moles of HBr
according to the reaction: 1 mole of KOH = 1 mole of HBr
so
0,0225 moles of HBr = 0,0225 moles of KOH
0,0225 mole of KOH------in-----45ml
x moles of KOH -----------in------1000ml
x = 0,5 moles of KOH
answer: 0,5 mol/dm³ KOH (molarity)
To help them discover new constructive forces on earth