Answer:
e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added.
Explanation:
<em>Which statement is incorrect?
</em>
<em>Select one:
</em>
<em>
a. The volume of solution in the buret should be recorded when the endpoint is reached.
</em> CORRECT. At the endpoint, the titrant is expected to have completely reacted with the titrand.
<em>b. It is good practice to place the flask over a white background to better observe the color change of the solution.</em> CORRECT. Using a white background makes it easier to detect the changes in the color of the indicator.
<em>c. The endpoint is when the indicator changes color.</em>
CORRECT. This is the function of an indicator.
<em>d. Phenolphthalein will go from a colorless solution to a pink solution for the addition of NaOH to an acid solution.</em> CORRECT. Phenolphthalein is colorless when pH < 8.3 and it is pink when pH > 10.0.
<em>e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added.</em> INCORRECT. When the endpoint is reached, no more titrant should be added.
Answer:
The heat at constant pressure is -3,275.7413 kJ
Explanation:
The combustion equation is 2C₆H₆ (l) + 15O₂ (g) → 12CO₂ (g) + 6H₂O (l)
= (12 - 15)/2 = -3/2
We have;
Where R and T are constant, and ΔU is given we can write the relationship as follows;
Where;
H = The heat at constant pressure
U = The heat at constant volume = -3,272 kJ
= The change in the number of gas molecules per mole
R = The universal gas constant = 8.314 J/(mol·K)
T = The temperature = 300 K
Therefore, we get;
H = -3,272 kJ + (-3/2) mol ×8.314 J/(mol·K) ×300 K) × 1 kJ/(1000 J) = -3,275.7413 kJ
The heat at constant pressure, H = -3,275.7413 kJ.
I am almost positive that the answer is D
132 grams x (1 mol / 44 grams) = 3 moles
<span>3 moles X (22.4 L/ 1 mol) = 67.2 </span><span>L</span>
