Answer:
D. The electron-withdrawing fluorine atoms pull electron density from the oxygen in trifluoroacetate. The negative charge is more stabilized in trifluoroacetate by this effect.
Explanation:
The structures of trifluoroacetate and acetic acid are both shown in the image attached.
The trifluoroacetate anion (CF3CO2-), just like the acetate anion has in the middle, two oxygen atoms.
However, in the trifluoroacetate anion, there are also three electronegative fluorine atoms attached to the nearby carbon atom attached to the carbonyl, and these pull some electron density through the sigma bonding network away from the oxygen atoms, thereby spreading out the negative charge further. This effect, called the "inductive effect" stabilizes the anion formed,the trifouoroacetate anion is thus more stabilized than the acetate anion.
Hence, trifluoroacetic acid is a stronger acid than acetic acid, having a pKa of -0.18.
Answer:

Explanation:
Concentration: i is defined as the mole per litre.

mole=0.15
volume=400 ml=0.4 litre

Answer:
1.818x10²³ particles
Explanation:
Add the two atomic masses given to get 74.55 g.
Divide the number of grams given by the molar mass of KCl:
22.5g ÷ 74.55 = 0.302 mol
Multiply the moles by 6.022×10²³ particles
The hydrate form of CuSO4 has 5 water molecules (CuSO4-5H20) copper (II) Sulfate pentahydrate or commonly known as blue vitriol.
To solve, the following molar masses are to be known.
CuSO4.5H2O (hydrate) - 249.7g/mole
CuSO4 (anhydrous) -159.6g/mole
Also there molar ratio of the hydrate and CuSO4 is 1.
the mass of the hydrate is to be divided by the molar mass of the hydrate then multiplied by the ratio (1) to get the moles of hydrate and multiplied by the molar mass of the anhydrous to get the mass in grams.
moles = (100g/249.7)*1 = 0.4 moles hydrate
grams = 0.4*159.6 = 64.9 grames hydrate