Density is calculated using the following rule:
density = mass / volume
therefore:
mass = density * volume
mass of Hg = 13.6 * 60.2 = 818.72 grams
From the periodic table:
molar mass of Hg = 200.59 grams
number of moles = mass / molar mass
number of moles of Hg = 818.72 / 200.59 = 4.08 moles
each mole contains Avogadro's number of atoms.
Therefore,
number of atoms in the given sample = 4.08 * 6.022 * 10^23
= 2.456976 * 10^24 atoms
First, we have to get the initial [C6H8O6] = mass/molar mass
when the molar mass of C6H8O6 = 176.12 g/mol
∴[C6H8O6] = 0.25 g / 176.12 g/mol
= 0.00142 M
when
C6H8O6 ⇄ H+ + C6H7O6-
intial 0.00142 M 0 0
change -X +X +X
Equ (0.00142-X) X X
so, Ka = [H+][C6H7O6-] / [C6H8O6]
by substitution:
8 x 10^-5 = X * X / (0.00142-X) by solving this equation for X
∴ X = 0.000299
∴[H+] = 0.000299
∴PH = -㏒[H+]
= -㏒ 0.000299
= 3.52
Answer:2
Explanation:
Ba(OH)2 contains two oxygen atoms
BaSO4 contains four oxygen atoms.
This means that barium sulphate contains two more oxygen atoms than barium hydroxide in its formula. This is clearly seen from the two formulae shown above.
In this question, you are given the NaOH volume but asked for concentration.
Don't forget that for every 1 mol of NaOH there will be 1 mol OH- ion, but for every 1 mol of H2SO4 there will be 2 mol of H- ion.
To neutralize you need the same amount of OH- and H+, so the equation should be:
OH-= H+
<span>35.50cm3 * x*1= 25cm3* 0.2mol/dm3 *2
</span>x= 10/35.5 mol/dm3= 0.2816/dm3
Volume = Mass / Density
Volume = 540g / 2.70 g/ml
Volume = 200 ml
