Answer:
The process of dissolving is exothermic when more energy is released when water molecules “bond” to the solute than is used to pull the solute apart. Because more energy is released than is used, the molecules of the solution move faster, making the temperature increase.
Project the image Endothermic Dissolving.
The process of dissolving is endothermic when less energy is released when water molecules “bond” to the solute than is used to pull the solute apart. Because less energy is released than is used, the molecules of the solution move more slowly, making the temperature decrease.
Answer:
1.42 L
Explanation:
Step 1:
The following data were obtained from the question :
Molarity of KBr = 2.40 M
Mole of KBr = 3.40 moles
Volume of solution =?
Step 2:
Determination of the volume of the solution.
Molarity of solution is simply the mole of the solute per unit volume the of solution. It is given as :
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 3.4/2.4
Volume = 1.42 L
Therefore, the volume of the solution is 1.42 L
C. Represents an oxidation-reduction reaction
According to this formula :
㏑[A] /[Ao] = - Kt
when we have Ao = 0.3 m
and K =0.46 s^-1
t = 20min = 0.2 x 60 =12 s
So by substitution :
㏑[A] / 0.3 = - 0.46 * 12
㏑[A] / 0.3 = - 5.52
by taking e^x for both side of the equation we can get [A]
∴[A] = 0.0012 mol dm^-3
