Answer:
Solid turns to liquid.
Explanation:
When you freeze water, it turns into ice. When melted it's still water. No chemical changes were made to the piece of ice melted. The only change was ice (solid) to water (liquid)
Conservation of Matter - Matter can change forms through physical and chemical changes, but no matter what, matter is conserved. The same amount of matter exists before and after the change.
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Answer:
6.5x10⁻³M = [OH⁻]
Explanation:
The Kb of a Weak base as ethylamine is expressed as follows:
Kb = [OH⁻] [C₂H₅NH₃⁺] / [C₂H₅NH₂]
As the equilibrium of ethylenamine is:
C₂H₅NH₂(aq) + H₂O(l) ⇄ C₂H₅NH₃⁺(aq) + OH(aq)
The concentration of C₂H₅NH₃⁺(aq) + OH(aq) is the same because both ions comes from the same equilibrium. Thus, we can write:
Kb = [OH⁻] [C₂H₅NH₃⁺] / [C₂H₅NH₂]
6.4x10⁻⁴ = [X] [X] / [C₂H₅NH₂]
Also, we can assume the concentration of ethylamine doesn't decrease. Replacing:
6.4x10⁻⁴ = [X] [X] / [0.066M]
4.224x10⁻⁵ = X²
6.5x10⁻³M = X
<h3>6.5x10⁻³M = [OH⁻]</h3>
Answer:
0.01 M
Explanation:
The chemist is performing a serial dilution in order tyo obtain the calibration curve for the instrument.
First we must obtain the concentration of the solution in the 250ml flask from
C1V1 = C2V2
Where;
C1 = concentration of the stock solution
V1 = volume of the stock solution
C2 = concentration of the diluted solution
V2= volume of the diluted solution
2.61 × 10 = C2 × 250
C2 = 2.61 × 10/250
C2 = 0.1 M
Hence for solution in 100ml flask;
0.1 × 10 = C2 × 100
C2 = 0.1 × 10/100
C2 = 0.01 M
Answer:
6080 N
Explanation:
From the question given above, the following data were obtained:
Mass (m) of car = 800 Kg
Acceleration (a) of car = 7.6 m/s²
Force (F) =?
The force experienced by the car can be obtained as illustrated below:
Force (F) = mass (m) × acceleration (a)
F = m × a
F = 800 × 7.6
F = 6080 N
Thus, the experience a force of 6080 N
