An isotope contains 47 protons, 47 electrons, and 60 neutrons

If acetic acid is the only acid that vinegar contains (ka=1.8×10−5), calculate the concentration of acetic acid in the vinegar.

kicyunya [14]

Ethanoic (Acetic) acid is a weak acid and do not dissociate fully. Therefore its equilibrium state has to be considered here.

$CH_{3}COOH \ \textless \ ---\ \textgreater \ H^{+} + CH_{3}COO^{-}$

In this case pH value of the solution is necessary to calculate the concentration but it's not given here so pH = 2.88 (looked it up)

pH = 2.88 ==> $[H^{+}]$ = $10^{-2.88}$ = 0.001 $moldm^{-3}$

The change in Concentration Δ $[CH_{3}COOH]$ = 0.001 $moldm^{-3}$

  CH3COOH H+ CH3COOH
Initial   $moldm^{-3}$      $x$ 0 0

Change $moldm^{-3}$ -0.001 +0.001 +0.001

Equilibrium $moldm^{-3}$ $x$ - 0.001 0.001 0.001


Since the $k_{a}$ value is so small, the assumption
$[CH_{3}COOH]_{initial} = [CH_{3}COOH]_{equilibrium}$ can be made.

$k_{a} = [tex]= 1.8*10^{-5} = \frac{[H^{+}][CH_{3}COO^{-}]}{[CH_{3}COOH]} = \frac{0.001^{2}}{x}$

Solve for x to get the required concentration.

note: 1.)Since you need the answer in 2SF don&t round up values in the middle of the calculation like I've done here.

2.) The ICE (Initial, Change, Equilibrium) table may come in handy if you are new to problems of this kind

Hope this helps!

8 0

3 years ago

Which of the following elements is the most metallic

Marysya12 [62]

We found cesium, strontium, aluminum, sulfur, chlorine, and fluorine on the periodic table. Cesium is the farthest left and the lowest, while fluorine is the farthest right and the highest, so we know they have the highest metallic character and the lowest metallic character, respectively.

7 0

3 years ago

Read 2 more answers

I need the answers to all three questions pls:

Klio2033 [76]

Answer:

Explanation:

8) As a sulfur atom gains electrons, its radius

A) decreases

B) increases

C) remains the same

Answer:

Increases

Explanation:

when an atom form ion its atomic radius changed from neutral atomic radius.

if the atom form cation its atomic radius is smaller than neutral atomic radius.

If atom form anion its anionic radius is larger than the neutral atomic radius.

The reason is that when electron is remove energy shell deduced so cation get smaller ionic radii while in case of anion electron is added and size increase.

when sulfur gain electrons it form anion that's why its radius increases.

9) Which element forms an ion larger than its atom?

A) Na B) Ne C) Ba D) Br

Answer;

Br

Explanation:

when an atom form ion its atomic radius changed from neutral atomic radius.

if the atom form cation its atomic radius is smaller than neutral atomic radius.

If atom form anion its anionic radius is larger than the neutral atomic radius.

The reason is that when electron is remove energy shell deduced so cation get smaller ionic radii while in case of anion electron is added and size increase.

In given list of elements sodium and barium form cation while bromine form anion.

That's why anion of bromine is larger than atom.

while neon is inert it cannot form ion.

10. Which of the following particles has the smallest

radius?

A) Na B) K° C) Na+ D) K+

Answer:

Na⁺

Explanation:

Atomic radii trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased .

Sodium and potassium are present in group one. Sodium is present in period three while potassium is present in period four. So atomic size of sodium is smaller and when it form the cation its cation is smaller than its atom because of losing of electron.The reason is that when electron is remove energy shell deduced so cation get smaller ionic radii

8 0

3 years ago

Need help with the question

Sloan [31]

Answer:

for a i think it is choice 2

for b i think it is the first choice

Explanation:

3 0

2 years ago

1. How many covalent bonds can nitrogen form?

-Dominant- [34]

Answer:

1. 3 covalent bonds

2. CO2

4 0

2 years ago