Which of the following is an empirical formula? a) H2O2 b) H2O c) C2H2 d) C4H8

An unknown triprotic acid (H3A) is titrated with NaOH. After the titration Ka1 is determined to be 0.0013 and Ka2 is determined

e-lub [12.9K]

Answer:

6.68 X 10^-11

Explanation:

From the second Ka, you can calculate pKa = -log (Ka2) = 6.187

The pH at the second equivalence point (8.181) will be the average of pKa2 and pKa3. So,

8.181 = (6.187 + pKa3) / 2

Solving gives pKa3 = 10.175, and Ka3 = 10^-pKa3 = 6.68 X 10^-11

7 0

3 years ago

The powder mixture (Cu, Al and Fe) = 10g was oxidized from sufficient chloride acid. 1) What are the possible reactions to the p

Mandarinka [93]

Answer:

1) 2Al + 6HCl ⟶ 2AlCl₃ + 3H₂

Fe + 2HCl ⟶ FeCl₂ + H₂

2) Cu = 2.5 g; Al = 3.5 g; Fe = 4.0 g

Explanation:

1) Possible reactions

2Al + 6HCl ⟶ 2AlCl₃ + 3H₂

Fe + 2HCl ⟶ FeCl₂ + H₂

2) Mass of each metal

a) Mass of Cu

The waste was the unreacted copper.

Mass of Cu = 2.5 g

b) Masses of Al and Fe

We have two relations :

Mass of Al + mass of Fe = 10 g - 2.5 g = 7.5 g

H₂ from Al + H₂ from Fe = 6.38 L at NTP

i) Calculate the moles of H₂

NTP is 20 °C and 1 atm.

$\begin{array}{rcl}pV & = & n RT\\\text{1 atm} \times \text{6.38 L} & = & n \times 0.08206 \text{ L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times \text{293.15 K}\\6.38 & = & 24.06n \text{ mol}^{-1} \\n & = & \dfrac{6.38}{24.06 \text{ mol}^{-1} }\\\\ & = & \text{0.2652 mol}\\\end{array}$

(ii) Solve the relationship

Let x = mass of Al. Then

7.5 - x = mass of Fe

Moles of Al = x/27

Moles of Fe = (7.5 - x)/56

Moles of H₂ from Al = (3/2) × Moles of Al = (3/2) × (x/27) = x /18

Moles of H₂ from Fe = (1/1) × Moles of Fe = (7.5 - x)/56

∴ x/18 + (7.5 - x)/56 = 0.2652

56x + 18(7.5 - x) = 267.3

56x + 135 - 18x = 267.3

38x = 132.3

x = 3.5 g

Mass of Al = 3.5 g

Mass of Fe = 7.5 g - 3.5 g = 4.0 g

The masses of the metals are Cu = 2.5 g; Al = 3.5 g; Fe = 4.0 g

4 0

4 years ago

At the most basic level, in order to produce oxygen and a carbohydrate (comprised of carbon, hydrogen, and oxygen), carbon dioxi

Kaylis [27]

At the most basic level, in order to produce oxygen and a carbohydrate (comprised of carbon, hydrogen, and oxygen), carbon dioxide must react with water as a source of hydrogen.

In order to construct carbohydrate molecules (often glucose) and release oxygen into the atmosphere, photosynthesis utilises carbon dioxide and water. Photosynthesis occurs in organelles called chloroplasts found in eukaryotic autotrophs like plants and algae.

Commonly used notation for photosynthesis is:

6CO $_{2}$ + 6H $_{2}$ O C $_{6}$ H $_{12}$ O $_{6}$ + 6O $_{2}$

This indicates that the reactants, six carbon dioxide molecules and six water molecules, are transformed into a sugar molecule and six oxygen molecules, the products, by light energy being absorbed by chlorophyll.

Learn more about water here:

brainly.com/question/16630851

#SPJ4

8 0

2 years ago

For a species with a diploid number of 26, indicate how many chromosomes will be present in the somatic nuclei of individuals th

Sedbober [7]

Answer:

Haploid - 13

Triploid - 39

Tetraploid - 52

Trisomic - 27

Monosomic - 25

Explanation:

A haploid organism has half the chromosome number of a diploid version, hence 26/2 = 13

A triploid organism has 3 sets of a haploid chromosomes, hence 13 x 3 = 39

A tetraploid is double of a diploid, 26 x 2 = 52

Trisomic organisms have one extra chromosome in addition to the normal diploid. Hence 26 + 1 = 27

Monosomic organism has one less chromosome than the normal diploid. Hence 26 - 1 = 25

6 0

3 years ago

Label one of the test tubes Fe2+. Add 4 milliliters of iron(II) sulfate to the test tube.

Mila [183]

Answer: A: Has little to no reaction; might turn slightly red in color. B: The liquid grows darker in color to a more reddish tone.

Explanation: I didn’t have the necessary materials to complete the experiment so the teacher told me and I put it in my own words.

8 0

3 years ago