Answer:
C. 0.191 M
Explanation:
Our goal for this question, is to calculate the concentration of the HCl solution. For this, in the experiment, a solution of NaOH was used to find the moles of HCl. Therefore, our first step is to know the <u>reaction between HCl and NaOH</u>:

The "<u>titrant"</u> in this case is the NaOH solution. If we know the concentration of NaOH (0.100M) and the volume of NaOH (38.2 mL=0.0382 L), we can calculate the moles using the <u>molarity equation</u>:



Now, in the reaction, we have a <u>1:1 molar ratio</u> between HCl and NaOH (1 mol of HCl is consumed for each mole of NaOH added). Therefore we will have the same amount of moles of HCl in the solution:

If we want to calculate the molarity of the HCl solution we have to <u>divide by the litters</u> of HCl used in the experiment (20 mL= 0.02 L):

The concentration of the HCl solution is 0.191 M
I hope it helps!
Answer:
π = 4.1 atm
Explanation:
We can calculate the osmotic pressure exerted by a solution using the following expression.
π = M . R . T
where,
π is the osmotic pressure
M is the molar concentration of the solution
R is the ideal gas constant
T is the absolute temperature
The absolute temperature is 37 + 273 = 310 K
π = M . R . T
π = (0.16 mol/L) . (0.082atm.L/mol.K) . 310 K = 4.1 atm
2.1.695 isn’t a real number?? but if it’s like number two on a paper it would be 1.695 x 104 - 1.395 x 1015=-1239.645
B) O^2-
Hope this helped :)
Correct answer: <span>An isomer with a branched structure will require:
less energy to melt than the straight chain structure.
Reason:
</span>
The branched chain compounds have lower melting and boiling points as compared to straight chain isomers.This is due to the fact that branching makes the molecule more compact. This results in decreases in surface area of isomer. But, the intermolecular attractive forces depends on the surface area of compound. Thus, branched isomers have lower intermolecular force of interaction, as compared to straight chain isomers. Consequently, the melting/boiling points of the branched chain isomers are lower as compared to straight chain isomers.