Answer :
The correct answer is due to incorrect position of thermometer .
Distillation is process of separating two volatile liquids on the basis of their boiling points .In involves the following set up ( shown in image )
Since the Boiling point is found is 116-117 C which is near to 124 C , also the purity was checked and thermometer was calibrated .
So the only error could be possible is position of thermometer .
The position of bulb of thermometer is very important to get an accurate reading of boiling point .The vapor so formed should touch the side walls of bulb as soon as they are formed .
May be the bulb of thermometer was kept far from the vapors formed by liquid so, s<u>ome of the vapor before reaching to bulb start condensing and their Temperature decreases </u>.
Hence , the temperature shown by thermometer was decrease than actual boiling point due to incorrect position of thermometer.
Answer:
B) Their valence shell is full
Explanation:
In order to be classified as a noble gas, an element must have a complete octet/ a full shell of valence electrons, as shown in answer B.
A and C are just incorrect. Since noble gasses are very unstable, D is a true statement, but is isn't the correct answer as this does not explain why they are inert.
<h3>Hope this was helpful!</h3>
This problem could be solved easily using the Henderson-Hasselbach equation used for preparing buffer solutions. The equation is written below:
pH = pKa + log[(salt/acid]
Where salt represents the molarity of salt (sodium lactate), while acid is the molarity of acid (lactic acid).
Moles of salt = 1 mol/L * 25 mL * 1 L/1000 mL = 0.025 moles salt
Moles of acid = 1 mol/L* 60 mL * 1 L/1000 mL = 0.06 moles acid
Total Volume = (25 mL + 60 mL)*(1 L/1000 mL) = 0.085 L
Molarity of salt = 0.025 mol/0.085 L = 0.29412 M
Molarity of acid = 0.06 mol/0.085 L = 0.70588 M
Thus,
pH = 3.86 + log(0.29412/0.70588)
pH = 3.48
