All categories

2 years ago

HELP!! b. At the equivalence point, all of the acid has been neutralized by the base. Why does the pH change so

1 answer:

3 0

At equivalence there is no more HA and no more NaOH, for this particular reaction. So that means we have a beaker of NaA and H2O. The H2O contributes 1 x 10-7 M hydrogen ion and hydroxide ion. But NaA is completely soluble because group 1 ion compounds are always soluble. So NaA breaks apart in water and it just so happens to be in water. So now NaA is broken up. The Na+ doesn't change the pH but the A- does change the pH. Remember that the A anion is from a weak acid. That means it will easily attract a hydrogen ion if one is available. What do you know? The A anion is in a beaker of H+ ions! So the A- will attract H+ and become HA. When this happens, it leaves OH-, creating a basic solution, as shown below.

You might be interested in

All modern fertilizers use PO43- as a source of phosphorus. Use your knowledge of the old methods to determine the moles of phos

tamaranim1 [39]

Answer:

The answer is 0.023 moles of phosphorus

Explanation:

The 15-15-15 fertilizer is a fertilizer of great versatility, made with nitrogen, phosphorus and potassium, which makes it one of the fertilizers most used for fertilizer in the sowing plant, thus covering the crop requirements from planting. .

This fertilizer consists of 14.25% phosphorus pentoxide (P2O5). Therefore, we have to remove 14.25% at 10 grams of 15-15-15 fertilizer to calculate the moles of phosphorus. As follows:

Grams of P2O5 = 10 g x 0.1425 = 1.425 g

We calculate the molecular weight of phosphorus. We use the periodic table:

Phosphorus molecular weight = 2 x 30.97 = 61.94 g/mol

Now we calculate the moles of phosphorus in the fertilizer:

Phosphorus moles = 1,425 g/61.94 g/mol = 0.023 moles

8 0

2 years ago

Balance the reaction for the combustion of pentane: ?C5H12+?O2→?CO2+?H2O Enter the four coefficients in order, separated by comm

Daniel [21]

Answer:

The four coefficients in order, separated by commas are 1, 8, 5, 6

Explanation:

We count the atoms in order to balance this combustion reaction. In combustion reactions, the products are always water and carbon dioxide.

C₅H₁₂ + ?O₂→ ?CO₂ + ?H₂O

We have 12 hydrogen in right side and we can balance with 6 in the left side. But the number of oxygen is odd. We add 2 in the right side, so we have 24 H, and in the product side we add a 12.

As we add 2 in the C₅H₁₂, we have 10 C, so we must add 10 to the CO₂ in the product side.

Let's count the oxygens: 20 from the CO₂ + 12 from the water = 32.

We add 16 in the reactant side. Balanced equation is:

2C₅H₁₂ + 16O₂→ 10CO₂ + 12H₂O

We also can divide by /2 in order to have the lowest stoichiometry

C₅H₁₂ + 8O₂→ 5CO₂ + 6H₂O

6 0

3 years ago

Select the correct value for the indicated bond angle in each of the following compounds: O-S-O angle of SO2 F-B-F angle of BF3

Stels [109]

Answer:

(A) O-S-O bond angle of SO₂ molecule = 119°

(B) F-B-F bond angle of BF₃ molecule = 120°

(D) O-C-O bond angle of CO₂ molecule = 180°

(E) F-P-F bond angle of PF₃ molecule = 96.3°

(F) H-C-H bond angle of CH₄ molecule = 109.5°

Explanation:

Bond angle refers to the angle between two adjacent chemical bonds in a molecule. The bond angle is different for different molecular geometry.

The Valence shell electron pair repulsion theory predicts the molecular geometry and shape of the given molecule by the number of lone pairs on central atom and number of atoms bonded to central atom.

(A) SO₂ molecule

The number of atoms bonded to S = 2

Number of lone pairs on S = 1

Therefore, the shape of SO₂ molecule is bent and the O-S-O bond angle is 119°.

(B) BF₃ molecule

The number of atoms bonded to B = 3

Number of lone pairs on B = 0

Therefore, the shape of BF₃ molecule is trigonal planar and the F-B-F bond angle is 120°.

(C) SCl₂ molecule

The number of atoms bonded to S = 2

Number of lone pairs on S = 2

Therefore, the shape of SCl₂ molecule is bent and the Cl-S-Cl bond angle is 103°.

(D) CO₂ molecule

The number of atoms bonded to C = 2

Number of lone pairs on C = 0

Therefore, the shape of CO₂ molecule is linear and the O-C-O bond angle is 180°.

(E) PF₃ molecule

The number of atoms bonded to P = 3

Number of lone pairs on P = 1

Therefore, the shape of PF₃ molecule is trigonal pyramidal and the F-P-F bond angle is 96.3°.

(F) CH₄ molecule

The number of atoms bonded to C = 4

Number of lone pairs on C = 0

Therefore, the shape of CH₄ molecule is tetrahedral and the H-C-H bond angle is 109.5°.

7 0

3 years ago

The statement “the scientific process is open ended” means:

mina [271]

Answer:

think it helps you

<h2>Explanation:</h2>

The statement “the scientific process is open ended” means: Would an element with 7 valence electrons be more or less reactive than an element with 3 valence electrons? Element 1 is a hard dark-red solid

4 0

2 years ago

Two steps in a synthesis of the analgesic ibuprofen include a carbonyl condensation reaction, followed by an alkylation reaction

Tresset [83]

Ibuprofen is synthesized by reacting ethyl 2-(4-isobutylphenyl)acetate with base, the base abstracts the acidic proton and enolate is formed which on reaction with diethyl carbonate generates diethyl 2-(4-isobutylphenyl)malonate (A). diethyl 2-(4-isobutylphenyl)malonate on treatment with Base again looses the acidic proton and forms enolate. The enolate with treatment with Methyl Iodide yields diethyl 2-(4-isobutylphenyl)-2-methylmalonate (B). diethyl 2-(4-isobutylphenyl)-2-methylmalonate on hydrolysis give Ibuprofen.

4 0

2 years ago

Read 2 more answers