What are the answer choices?
Answer:
0.464 L
Explanation:
Molarity (M) = number moles (n) ÷ volume (V)
According to the information given in this question:
number of moles (n) = 4.36 moles
Molarity = 9.4M
Volume = ?
Using M = n/V
9.4 = 4.36/V
9.4V = 4.36
V = 4.36/9.4
V = 0.464 L
Hence, 0.464L of water are needed the volume of water.
a typable representation of emotion
Water is made of only one molecule which can be chemically separated into hydrogen and oxygen. The answer is D.
Answer:
b) 3.10
Explanation:
HF ⇄ H
+ + F
Using Henderson-Hasselbalch Equation:
pH = pKa + log [A-]/[HA].
Where;
pKa = Dissociation constant = -log Ka
Hence, pKa of HF = -log 7.2 x 10^-4 = 3.14266
[A-] = concentration of conjugate base after dissociation = moles of base/total volume
= 0.15 x 0.3/0.8
= 0.05625 M
[HA] = concentration of the acid = moles of acid/total volume
= 0.10 x 0.5/0.8
= 0.0625 M
Note: <em>Total volume = 500 + 300 = 800 mL = 0.8 dm3</em>
pH = 3.14266 + log [0.05625/0.0625]
= 3.14267 + (-0.04575749056)
= 3.09691250944
<em>From all the available options below:</em>
<em>a) 2.97
</em>
<em>b) 3.10
</em>
<em>c) 3.19
</em>
<em>d) 3.22
</em>
<em>e) 3.32</em>
The correct option is b.
