Explanation:
The answer is mentioned above.
Hope it helps.
Answer:
28.58 g of NaOH
Explanation:
The question is incomplete. The missing part is:
<em>"Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step"</em>
To do this, we need to know how much of the base we have to weight to prepare this solution.
First we know that is a sodium hydroxide aqueous solution so, this will dissociate in the ions:
NaOH -------> Na⁺ + OH⁻
As NaOH is a strong base, it will dissociate completely in solution, so, starting with the pH we need to calculate the concentration of OH⁻.
This can be done with the following expression:
14 = pH + pOH
and pOH = -log[OH⁻]
So all we have to do is solve for pOH and then, [OH⁻]. To get the pOH:
pOH = 14 - 13.9 = 0.10
[OH⁻] = 10⁽⁻⁰°¹⁰⁾
[OH⁻] = 0.794 M
Now that we have the concentration, let's calculate the moles that needs to be in the 900 mL:
n = M * V
n = 0.794 * 0.9
n = 0.7146 moles
Finally, to get the mass that need to be weighted, we need to molecular mass of NaOH which is 39.997 g/mol so the mass:
m = 39.997 * 0.7146
<h2>
m = 28.58 g</h2>
it's the last one because it's depended on the rock layers
Answer:
digestive system, mechanical digestion, chemical digestion, circulatory system and the nervous system
Explanation:
Answer:
The acceleration of the car is -5m/s²
Explanation:
Given parameters:
Initial velocity = 75m/s
Final velocity = 0m/s
Time = 15s
Unknown:
Acceleration of the car = ?
Solution:
Acceleration is the rate of change of velocity with time;
Mathematically;
Acceleration = 
Insert parameters and solve,
Acceleration = 
= -5m/s²
The acceleration of the car is -5m/s²
