Hydroquinone is an organic compound commonly used as a photographic developer. It has a molecular weight of

Which of the following bases is the STRONGEST? The base is followed by its Kb.A. C6H5NH2, 4.0 × 10-10 B. NH3, 1.76 × 10-5 C. CH3

Kamila [148]

Answer:

(D) (CH3CH2)2NH

Explanation:

In order to decide which base is strongest we need to calculate its PKb

PKb = -log [Kb]

A large Kb value and small PKb value gives the strongest base

Compound Kb PKb

(A) C6H5NH2 - 4 x 10^-10 9.349

(B) NH3 1.76x 10^-5 4.754

(C) CH3NH2 4.4x 10^-4 3.357

(D) (CH3CH2)2NH 8.6x 10^-4 3.066

(E) C5H5N 1.7x10^-9 8.77

Clearly (CH3CH2)2NH is the strongest base.

3 0

3 years ago

A student used 1.168g of an unknown weak acid and titrated it against 28.75 mL of 0.105M NaOH to reach the equivalence point. Wh

Vaselesa [24]

Answer:

The molar mass of the unknown acid is 386.8 g/mol

Explanation:

Step 1: Data given

Mass of the weak acid = 1.168 grams

volume of NaOH = 28.75 mL = 0.02875 L

Molarity of NaOH = 0.105 M

Since we only know 1 equivalence point, we suppose the acid is monoprotic

Step 2: Calculate moles NaOH

Moles NaOH = molarity NaOH * volume NaOH

Moles NaOH = 0.105 M * 0.02875 L

Moles NaOH = 0.00302 moles

We need 0.00302 moles of weak acid to neutralize the NaOH

Step 3: Calculate molar mass of weak acid

Molar mass = mass / moles

Molar mass = 1.168 grams / 0.00302 moles

Molar mass = 386.8 g/mol

The molar mass of the unknown acid is 386.8 g/mol

3 0

3 years ago

.7 liters of CO represents how many molecules?

Ronch [10]

Answer:

1.88 × 10²² Molecules of CO

Explanation:

At STP for an ideal gas,

Volume = Mole × 22.4 L/mol

Or,

Mole = Volume / 22.4 L/mol

Mole = 0.7 L / 22.4 L/mol

Mole = 0.03125 moles

Now,

No. of Molecules = Moles × 6.022 × 10²³ Molecules/mol

No. of Molecules = 0.03125 × 6.022 × 10²³ Molecules/mol

No. of Molecules = 1.88 × 10²² Molecules of CO

7 0

3 years ago

What type of energy is the sun of an objects potential and kinetic energy

Ulleksa [173]

All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.

6 0

4 years ago

Unlabeled atoms joined to carbon atoms, which are not directly part of a ring structure, are assumed to be oxygen atoms.

N76 [4]

The statement above is FALSE.
Unlabeled atom joined to carbon atoms which are not directly part of a ring structure are assumed to be CARBON ATOMS. In a ring structure, an unlabeled atom at the angle where two lines joined together is always assumed to be a carbon atom<span />

3 0

4 years ago