Answer:
Explanation:
Num of molecules = num of moles * Avogadro's constant (6.02* 10^23)
But num of moles = reacting mass / molar mass
Molar mass of H20= 2*1 + 16 = 2+16 = 18g
Reacting mass of H20 = 0.55g
Therefore, num of moles of H20 = 0.55g/18g = 0.031 moles
Therefore, num of molecules of H20 = 0.031 * 6.02*10^23
= 1.87*10^22 molecules of H20
We can set up an ICE table for the reaction:
HClO H+ ClO-
Initial 0.0375 0 0
Change -x +x +x
Equilibrium 0.0375-x x x
We calculate [H+] from Ka:
Ka = 3.0x10^-8 = [H+][ClO-]/[HClO] = (x)(x)/(0.0375-x)
Approximating that x is negligible compared to 0.0375 simplifies the equation to
3.0x10^-8 = (x)(x)/0.0375
3.0x10^-8 = x2/0.0375
x2 = (3.0x10^-8)(0.0375) = 1.125x10^-9
x = sqrt(1.125x10^-9) = 0.0000335 = 3.35x10^-5 = [H+]
in which 0.0000335 is indeed negligible compared to 0.0375.
We can now calculate pH:
pH = -log [H+] = - log (3.35 x 10^-5) = 4.47
Answer:
It kinda helps but not really
Thanks for trying anyway doe!
Explanation:
5.4 M = moles of solute / 1.50 L
<span>Multiply both sides by 1.50 L to isolate moles of solute on the right. </span>
<span>8.1 mol = moles of solute </span>