Answer:
Explanation:
-log(3.5 * 10^-11)
= 10.4559
Be careful how you put this into your calculator. I had to use Exp to get it to work properly.
-log
(3.5 * 10 exp -11)
=
Answer: 2m/s^2
Explanation:
Velocity of skateboard = 20.0 m/s.
Time taken = Ten seconds (10 s)
Acceleration = ?
Recall that acceleration is the change in velocity of a body per unit time.
i.e Acceleration = (velocity / Time)
Acceleration = 20.0m/s ➗ 10 s
Acceleration = 2m/s^2
Thus, Jeffrey acceleration was 2m/s^2
Answer:
Explanation:
This question seeks to test the knowledge of separation techniques.
From the narration in the question, the first separation to be done is the removal of Iron fillings by the use of magnet (magnetic separation). Since Iron is magnetic, the iron fillings will be attracted by the magnet hence removing the iron fillings from the mixture.
The second constituent to be removed will be the copper pieces by the use of a sieve (sieving). Copper pieces have relatively larger sizes than sand and common salt, hence a sieve (which separates particles based on size) can be used to remove the copper pieces from the mixture.
What will be left in the mixture after the processes above will be salt and water. This mixture will have to be dissolved in water; the salt will dissolve in water while the sand will not. After which, filtration will be done to remove the sand which will be collected on the filter paper as filtride and the salt solution will pass through the filter paper as filtrate.
The salt solution can then be evaporated to dryness to retrieve the solid salt from the solution.
The amount of salt in the mixture can then be measured using a weighing balance.
Some of safety measures to be taken during the course of this experiment includes performing the experiment in an airtight and controlled environment. Lab coat and hand gloves should be worn during the course of the experiment. The evaporation to dryness should not be done close to an inflammable material/substance
Answer:
D. Protons ; neutrons.
Explanation:
For a given element the number of protons is fixed, but the number of neutrons differ because the element usually consist of a number of isotopes.
For example Carbon has isotopes which contain 12, 13 and 14 neutrons.
So that is why you average the number of neutrons to find the approximate atomic mass..
Answer:
25.6mL NaOH
Explanation:
We are given the Molarity of the solution (
) and the volume of the solution (.02L).
By multiplying the two together, we can find the moles of solution that are reacted with HCl.
This gives us .0082 moles of HCl.
We then find the moles of NaOH that are needed to react with the HCl using the equation.
As HCl and NaCl have a 1:1 ratio, we need .0082 mol of NaOH.
Dividing this value by the Molarity of the solution
Gives us the answer, in Liters (.0256), which we can then divide by 100 convert to mL.
