Answer:
pKa = 3.675
Explanation:
∴ <em>C</em> X-281 = 0.079 M
∴ pH = 2.40
let X-281 a weak acid ( HA ):
∴ HA ↔ H+ + A-
⇒ Ka = [H+] * [A-] / [HA]
mass balance:
⇒<em> C</em> HA = 0.079 M = [HA] + [A-]
⇒ [HA] = 0.079 - [A-]
charge balance:
⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water
⇒ [H+] = [A-]
∴ pH = - log [H+] = 2.40
⇒ [H+] = 3.981 E-3 M
replacing in Ka:
⇒ Ka = [H+]² / ( 0.079 - [H+] )
⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )
⇒ Ka = 2.113 E-4
⇒ pKa = - Log ( 2.113 E-4 )
⇒ pKa = 3.675
How many moles of oxygen atoms are present in 5
moles of Mg3(PO4)2
All you have to do is to create
a ratio between the molecule and the oxygen atom.
5 moles of Mg3(PO4)2 (4x2 moles
O/1 mole Mg3(PO4)2) = 40 moles of oxygen
Answer:
<h2>10 m/s²</h2>
Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
f is the force
m is the mass
From the question we have
We have the final answer as
<h3>10 m/s²</h3>
Hope this helps you
Answer:
c.
Explanation:
If the object starts to slide it must be on a slope.
There are 2 forces acting on the object - gravity and the friction between the object and the surface.
If sliding starts then the forces must be unbalanced.
The force of gravity is greater than the friction.
- Corrosive<span> chemicals eat away and destroy things. </span>Flammable<span> things can be burned with fire. </span>
