Answer:
Explanation:
First we need to find how many moles of ammonium weigh 62 grams.
Molar mass of NH4 = (14.0)+(4*1.0) grams
or 18.0 grams/mole
62 (g)/18(g/mole) = 3.444... moles of NH4
If it is dissolved in 5 litres of water, the concentration will be 3.444moles/5L
or 0.6888 M.
Since you provide no options, Henry Moseley measured a property linked to Periodic Table position. After his revisions to the periodic table, Atomic number became more meaningful and the three pair of elements that seemed to be in the wrong order could be explained
Hello,
I believe that your answer would be <span>B. water freezes
</span>Hope this helps
Answer:
A 0.001 molar solution of weak acid has a pH = 4.0,The pKa is :
B. 5
Explanation:
pH = It is negative logarithm of hydrogen ion concentration.
pH = -log([H+])
Ka = It is the dissociation constant.
pKa = -log(Ka)
<u>The acid dissociates according to the equation given below:</u>
Here , The concentration of A- and H+ will be same
So,
[H+] = [A-].....(1)
Now ,
pH = 4.0
pH = -log([H+])
4.0 = -log([H+])
- 4.0 = log([H+]) take antilog both side::"use scientific calculator"
From equation (1), [A-] =
[HA] = 0.001 M (given)
Insert the value of HA , H+ and A- in Ka
pKa = -log(Ka)
pKa = 5