Which type of bond forms between atoms of iron (Fe)?

Rank these acids according to their expected pKa values.

givi [52]

Answer:

According to their expected pKa values, the order of those acids should be:

1- Cl2CHCOOH is the strongest acid and the lowest pKa.

2- ClCH2COOH is a strong acid, but no more than the first. Medium pKa value.

3- ClCH2CH2COOH is a strong acid, but no more than the two previous acids. High pKa value.

4- CH3CH2COOH is the weakest acid, so the highest pKa value.

Explanation:

The pKa values are the negative logarithm of dissociation constant. It represents the relative strengths of the acids. Stronger acids show smaller pKa values and weak acids present larger pKa value. The stronger the acid, the weaker it's the conjugate base. The larger the pKa of the conjugate base, the stronger the acid. The strength of an acid is inversely related to the strength of its conjugate.

Conjugate bases are the substance that has one less proton than the parent acid. The conjugate base of the acid presented in the problem are:

ClCH2COOH -> ClCH2COO- + H+

ClCH2CH2COOH -> ClCH2CH2COO- + H+

CH3CH2COOH -> CH3CH2COO- + H+

Cl2CHCOOH -> Cl2CHCOO - + H+

Cl2CHCOOH. The negative charge presented on its conjugate base is by resonance and inductive effect. This is the strongest acid.

ClCH2COOH. A negative charge is stabilized by resonance and electron-withdrawing but only one atom is present. So this acid is less strong than the first one.

ClCH2CH2COOH. The negative charge is stabilized by resonance and electron-withdrawing atom but the effect is less compared to the two acids showed previously.

CH3CH2COOH. The negative charge is stabilized by resonance and destabilized due to CH3 group. This is the weakest acid among the problem.

Stronger acids have smaller pKa values and weak acids have larger pKa values. Due to the information present in this problem, Cl2CHCOOH is the strongest acid and the lowest pKa. CH3CH2COOH is the weakest acid, so the highest pKa value.

Finally, we can conclude that according to their expected pKa values, the order of those acids should be:

1- Cl2CHCOOH is the strongest acid and the lowest pKa.

2- ClCH2COOH is a strong acid, but no more than the first. Medium pKa value.

3- ClCH2CH2COOH is a strong acid, but no more than the two previous acids. High pKa value.

4- CH3CH2COOH is the weakest acid, so the highest pKa value.

3 0

3 years ago

A 0.964 gram sample of a mixture of sodium formate and sodium chloride is analyzed by adding sulfuric acid. The equation for the

frosja888 [35]

Answer: 67.8 %.

Explanation:

Okay, let us delve right into the solution to the question;

The balanced chemical reaction is given by the equation (1) below;

2 HCOONa + H2SO4 ---------> 2 CO + 2 H2O + Na2SO4. ----------------------------------------------------------------------------(1).

From the balanced chemical reaction in equation (1) above we can see that; 2 moles of HCOONa reacts with one moles of tetraoxosulphate acid, H2SO4 to produce 2 moles of carbonmonoxide,CO; 2 moles of water, H2O and 1 mole of sodium tetraoxosulphate, Na2SO4.

The parameters given from the question are; total atmospheric pressure, P(t) = 752 torr, volume of CO= 242 mL = 0.242 Litres.

STEP ONE : find the carbon monoxide,CO pressure; P(CO).

Using the formula below;

P(t) = P(CO) + P(H2O). Hence;

P(CO) = P(t) - P(H2O). Note that P(H2O)= 19.8 torr.

==>P(CO)= 752 torr - 19.8 torr = 732.2 torr.

STEP TWO: calculate the number of moles of Carbonmonoxide,CO.

Using the formula below;

Number of moles= pressure(P) × volume(v) / gas constant(R) × temperature (T).

That is, n= PV/RT.

n= 732 torr × 0.242 Litres/ 62.4 × 295.15.

= 9.62 × 10^-3 mol of CO.

STEP THREE:

2 moles of HCOONa = 2 moles of CO.

=> 2 moles of HCOONa = 2 moles of CO/ 2 moles of CO = 1 mol( HCOONa/ CO).

Then, 9.62 × 10^-3 mol of CO × 1 mol( HCOONa/ CO).

==> 9.62 × 10^-3 mol HCOONa × molar masss of HCOONa(68 grams/mol)

= 0.654 grams.

Therefore, the percentage of sodium formate in the original mixture = 0.654 grams/ 0.964 gram × 100 = 67.8 %.

5 0

3 years ago

How many molecules of co2 are in a 500. 0 ml container at 780 mm hg and 135°c? 8. 76 × 1021 molecules 9. 23 × 1021 molecules 5.

Aloiza [94]

ok we have to use the formula PV=nRT

p=Pressure (must be converted to atm)= 780 mmHg

1 amt= 760 mmHg use this as a conversion factor

780 mmHg (1 atm/760 mmHg)= 1.026

V= Volume= 5.00 mL = o.5 L

n=number of moles which we have to find first

R= 0.0821

T(convert to Kelvins by adding 273.15 to the celsius temperature)= 135 C + 273.15= 408.15 k

Now plug in->

(1.026 atm)(o.5 L)= n(0.0821)(408.15 K)

(1.026 atm)(0.5 L)= n(33.509115)

(0.513)= n(33.509115)

n(number of moles)= 0.01532 mol

Now we have to convert to moles using Avagodro's number which states that 1 mol = 6.022 x 10^23 molecules or atoms

So 0.01532 mol (6.022 x 10^23 number of molesules)/ (1 mol) = 9.225704 x 10^21 = 9.226 x 10^21 colecules

Step 2

You must transfer pressure into pascals, 780 mm Hg = 103991 Pa

135*C = 408.15 k

then from the equation pV = nRt

n = pV / RT (T in Kelvins, V in M^3)

n = 103991 x 500 x 10^-6 / (8.314 x 408.15)= 0.015322 moles of N2

1 mol of everything is 6.022 x 10^23 particles, so 0.15322 moles is 0.15322 x 6.022 x 10^23 = 9.2269084 x 10^21 molecules

Explanation:

Hope this helps :)

5 0

2 years ago

Given the reaction at 101.3 kPa and 298 K: hydrogen gas + iodine gas -> hydrogen iodide gas This reaction is classified as

MaRussiya [10]

This is classified as a "Formation Reaction"

6 0

4 years ago

I need help with #129 please

Veronika [31]

The yield is 73%. If there is anything that isn’t clear, just send me a message.

8 0

4 years ago