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3 years ago

What does the letter R symbolize in a structural formula, such as RCOOH?

Chemistry

2 answers:

Bad White [126]3 years ago

7 0

Answer:

The correct answer is "a radical formed by carbons".

Explanation:

Carboxylic acids are a group of compounds characterized by a functional group called the carboxyl group. In a structural formula of a carboxylic acid, such as RCOOH, R symbolizes the existence of a radical formed by a certain amount of carbons attached to the functional group called the carboxyl group (COOH).

Have a nice day!

Illusion [34]3 years ago

3 0

Answer:

R means there's a number of carbon in the chain.

Explanation:

For example RCOOH means that after x number of carbon, the chain ends with COOH.

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The common name for butanone, a readily available solvent, is

azamat

Answer:

The common name for 2-butanone, a readily available solvent, is B-butanone

3 0

3 years ago

Which term describes this molecular shape?

ICE Princess25 [194]

Answer:

B.) Trigonal planar

Explanation:

This molecule has 3 bonds and no lone pairs. The angles are all 120° and the bonds are within the same plane. These molecules have the molecular shape of trigonal planar.

4 0

2 years ago

If a solution containing 23.81 g of lead(II) acetate is allowed to react completely with a solution containing 7.410 g of sodium

jeka57 [31]

Answer:

The correct answer is 15.80 grams.

Explanation:

The reaction taking place in the given question,

Pb(CH₃COO)₂ + Na₂SO₄ ⇒ PbSO₄ + 2NaCH₃COO

The number of moles can be calculated by using the formula,

n = weight / molecular mass

Based on the given question, the weight of lead (II) acetate is 23.81 grams and the weight of sodium sulfate is 7.410 grams.

The number of moles of Pb(CH₃COO)₂ is,

n = 23.81 g / 325.29 g/mol = 0.0732 moles

The number of moles of Na₂SO₄ is,

n = 7.410 g / 142.04 g/mol = 0.0521 moles

As one mole of lead (II) acetate needs one mole of sodium sulfate. Therefore, 0.0732 moles of lead (II) acetate needs 0.0732 moles of sodium sulfate.

However, as sodium sulfate is less, that is, 0.0521, therefore, Na₂SO₄ is a limiting reactant.

One mole of sodium sulfate produces one mole of PbSO₄. So, 0.0521 moles of Na₂SO₄ produces 0.0521 moles of PbSO₄.

Now the mass of PbSO₄ is,

mass = moles × molecular mass

mass = 0.0521 × 303.26 g/mol

mass = 15.80 grams.

6 0

3 years ago

Classify each amino acid according to whether its side chain is predominantly protonated or deprotonated at a pHpH of 7.40.7.40.

Zepler [3.9K]

Answer: His and Lys are deprotonated but Asp will be protonated.

Explanation:

As the pH is given as 7.4 and pK of His is given as 6.00. There will occur a positive charge on His when it's pH < pK therefore, it is neutral at the given pH.

As the pK value of Lys is 10.53 that is greater than the pH of 7.40. Therefore, charge on Lys is positive.

As the pK value of Asp is 3.65 which is less than the pH value of 7.40. Hence, Asp has a negative charge.

Therefore, we can conclude that His and Lys are deprotonated but Asp will be protonated.

3 0

4 years ago

A 2.600×10−2 M solution of glycerol (C3H8O3) in water is at 20.0∘C. The sample was created by dissolving a sample of C3H8O3 in w

sesenic [268]

Answer:

A. 0.2395 w/w %

B. 2394ppm

Explanation:

A. To find concentrationin percent by mass of the solution we need to calculate mass of glycerol and mass of water. The formula is:

Mass glycerol / Total mass * 100

<em>Mass glycerol:</em>

The solution is 2.6x10⁻²moles / L. As there is 1L of solution there are 2.6x10⁻² moles of glycerol. In mass (Using molar mass glycerol: 92.09g/mol):

2.6x10⁻² moles of glycerol * (92.09g / mol) = 2.394g glycerol

<em>Mass of water:</em>

998.9mL and density = 0.9982g/mL:

998.9mL * (0.9982g/mL) = 997.1g of water.

That means percent by mass is:

% by mass: 2.394g / (997.1g + 2.394g) * 100 = 0.2395 w/w %

B. Parts per million are mg of glycerol per L of solution. As in 1L there are 2.394g. In mg:

2.394g * (1000mg / 1g) = 2394mg:

Parts per million: 2394mg / L = 2394ppm

3 0

3 years ago