2. A book sits on a table. Which of the following is true?

How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule?

Alborosie

Answer:

During the polymerization of a 20 monomer-long cellulose molecule, 19 molecules of water are released.

Explanation:

In simple terms, cellulose is the biopolymer formed by many glucose units. This is cellulose is the polymer and glucose is the monomer.

To have a 20 monomer-long cellulose molecule, 20 monomers have been chemically bonded by reacting 19 times, as it is explained in the next paragrpahs, and so 19 molecules of water have been released.

You can imaging the polymerization process as a step-by-step reaction in which the first step is the condensation reaction of one glucose molelecule to produce a 2 monomer-long chain, with the release of one molecule of water: the second step would be the condensation reaction between the 2 monomer-long chain with another glucose molecule, with the release of an additional molecule of water, and so on, until 19 condensation reactions happen, to obtain the 20 monomer-long cellulose molecule.

Condensation is the loss of water in a chemical reaction.

When two glucose molecules react together, condensation occurs. One OH group from each glucose molecule come together, the OH from one glucose molecule combines with the H part of the OH from the other glucose molecule, to form H₂O (water that is released).

The two glucose molecules (monomers) will form one bigger molecule where the two glucose monomers are bonded through the oxygen atom that did not form part of the water molecule released.

Then, a 20-monomer chain means 19 condenstation reactions, with the release of 19 molecules of water.

8 0

2 years ago

In Part III, the phenolphthalein indicator is used to monitor the equilibrium shifts of the ammonia/ammonium ion system. The phe

AnnZ [28]

The pink color in the solution fades. Some of the colored indicator ion converts to the colorless indicator molecule.

<h3>Explanation</h3>

What's the initial color of the solution?

$\text{NH}_4\text{Cl}$ is a salt soluble in water. $\text{NH}_4\text{Cl}$ dissociates into ions completely when dissolved.

$\text{NH}_4\text{Cl} \; (aq)\to {\text{NH}_4}^{+} \; (aq) +{\text{Cl}}^{-} \; (aq)$ .

The first test tube used to contain $\text{NH}_4\text{OH}$ . $\text{NH}_4\text{OH}$ is a weak base that dissociates partially in water.

$\text{NH}_4\text{OH} \; (aq) \rightleftharpoons {\text{NH}_4}^{+} \;(aq)+ {\text{OH}}^{-} \; (aq)$ .

There's also an equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ ions.

${\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l)$ .

$\text{OH}^{-}$ ions from $\text{NH}_4\text{OH}$ will shift the equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ to the right and reduce the amount of ${\text{H}_3\text{O}}^{+}$ in the solution.

The indicator equilibrium will shift to the right to produce more ${\text{H}_3\text{O}}^{+}$ ions along with the colored indicator ions. The solution will show a pink color.

What's the color of the solution after adding NH₄Cl?

Adding $\text{NH}_4\text{Cl}$ will add to the concentration of ${\text{NH}_4}^{+}$ ions in the solution. Some of the ${\text{NH}_4}^{+}$ ions will combine with $\text{OH}^{-}$ ions to produce $\text{NH}_4\text{OH}$ .

The equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ ions will shift to the left to produce more of both ions.

${\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l)$

The indicator equilibrium will shift to the left as the concentration of ${\text{H}_3\text{O}}^{+}$ increases. There will be less colored ions and more colorless molecules in the test tube. The pink color will fade.

7 0

3 years ago

13. When a train car traveling at 4 m/s collides with a stationary train car, what happens to the momentum of the first train ca

Solnce55 [7]

Answer:

Momentum of first train car will reduce

Explanation:

When the moving care collides with the stationary car, it will increase the momentum of the stationary car. However, its own momentum will reduce.

It is so because the speed of the first train car will reduce after collision due to loss of energy in the collision while the stationary car may gain some momentum due to rise in velocity from zero (velocity at stationary position).

5 0

2 years ago

how does getting funding from the government affect scientific research?? a- the government helps the scientist decide what rese

sertanlavr [38]

Answer:

d- Scientists have to follow government rules made to protect people.

Explanation:

Scientific research fosters our understanding of the world around us. It helps people to learn to promote critical thought and problem-solving. Although there may not be an immediate practical use of the research, in the long term the study could benefit humanity. Scientific research is the product of creative ideas and collaborative communication that the proper role of government is often restricted to funding the research. The role of the government is to perform its reasonable and valid duties of defending human rights and enhancing the independence of the human.

4 0

2 years ago

What is the only thing that changes in a chemical reaction

kirill [66]

Bbbbbbbbbbbbbbbbbbbbb

3 0

3 years ago