Which two monomers may combine to form a polyester?

QUESTION POSTED AT 26/03/2020 - 03:24 PM

Answered by admin AT 26/03/2020 - 03:24 PM

Answer:

Monomer - terephthalic acid and ethylene

Explanation:

Polyester is also known as polyethylene terephthalate (PET) and the two monomer that combine to produce polyester are terephthalic acid and ethylene

Polyester can be produced from two other sets of monomers also such as  monomers containing one carboxyl group and one hydroxyl group.

An example of this kind of polyester is one made up of lactic acid and glycolic acid.

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Related questions

Observations of space show that galaxies are moving away from us as observers on Earth how is this related to how the universe is formed?

Answer:

Explanation:

since the big bang, Edwin Hubble in 1929 proved that the universe is expanding by the red shift theory, showing that things farther away from the earth were moving away faster so that the universe must be expanding.

ANSWERED AT 28/03/2020 - 12:25 PM


QUESTION POSTED AT 28/03/2020 - 12:25 PM

In a paragraph address these following questions: • How does an underwater earthquake cause a tsunami? • Why do some earthquakes cause more damage than others? the paragraph needs to also include the following things: • discuss how the different types of waves are formed and describe how the waves travel • explain how scientists use waves to track and analyze earthquakes • cover recent events involving earthquakes and/or tsunamis that illustrate the points made in your explanation

What is an Earthquake

Earthquakes are vibrations in the earth's crust They occur along all plate boundaries but are more destructive usually at destructive plate boundaries

How are they measured

The magnitude or size of an earthquake can be measured by an instrument called a seisometer and are shown on a seismograph. The earthquakes are measured on the Richter scale from a value of 1 to 10. Each level of magnitude is 10 times more powerful than the previous. Therefore a level 7 is 100 time more powerful than a level 5.

Why do some earthquakes cause more damage than others?

Some earthquakes take place in rural areas where few people live and little is damaged

If they occur near large urban areas with many people, transport services, large buildings and services such as gas and electricity - there can be a great amount of deaths and damage

In Poor countries - LEDC's they have poorly built buildings, few emergency facilities, and the equipment to help rescue people - a good term to use is that they have a poor infrastructure.

In rich countries - MEDC's such as the USA they prepare for an earthquake with drills and have a great deal of trained emergency personnel and equipment to go to help the injured. They also try to build to withstand earthquake damage - ie The Transamerica building

The time of day can be important - If the earthquake hits when it is the rush hour or when there is a large number of people located in a certain area - this can cause a great loss of life

Obviously if they occur near to coasts then Tsunamis can cause a great deal of damage and deaths such as the 2004 Boxing Day Tsunami

ANSWERED AT 28/03/2020 - 12:00 PM


QUESTION POSTED AT 28/03/2020 - 12:00 PM

Drag the names of the prevailing winds to the areas where they form in the Northern Hemisphere.

Air is curved to the right in the Northern hemisphere because of the Earth’s rotation and the Coriolis force. As a consequence, air movement in the polar cell circulation forms the polar easterlies. In the circulation cell that lies between 60° and 30° north, prevailing westerlies is formed.North trade winds on the other hand is formed in the tropic circulation cell. 

ANSWERED AT 28/03/2020 - 11:37 AM


QUESTION POSTED AT 28/03/2020 - 11:37 AM

Which of the following best compares the male and female reproductive structures of a gymnosperm? A Gymnosperms produce flowers, and the male stamens produce pollen that fertilizes the egg inside the female ovule. B Gymnosperms produce male cones and female cones, and the pollen from a male cone fertilizes the egg inside a female cone. C Gymnosperms have male sporangia and female archegonia, and spores fertilize eggs contained inside the embryo sac to form zygotes. D Gymnosperms exist as male and female gametophytes, and the male plant produces spores that fertilize eggs inside the female archegonia.

Answer: B Gymnosperms produce male cones and female cones, and the pollen from a male cone fertilizes the egg inside a female cone.  

Gymnosperms are terrestrial plants, which lacks flowers. The ovule or seeds are remains naked in hard woody structures called as cones. In the gymnosperms the green sporophyte generates cones that contains male and female gametophytes. A male cone consists of microsporophylls where male gametophyte also called as pollen are produced and released into the wind. The wind act as a agent for pollinating the female gametophyte present in the female cone.  Inside the female cone the megaspore mother cell produces four haploid megaspores, one megaspore divide itself to form the female gametopyte. The fusion of the pollen with the female gametophyte produces diploid zygote, which later on divides to form the embryo.

ANSWERED AT 28/03/2020 - 11:15 AM


QUESTION POSTED AT 28/03/2020 - 11:15 AM

. Metamorphic rocks that consist of only one mineral that forms large interlocking crystals often have a _____ texture.

They have a nonfoliated texture because they do not have a layered or banded appearance.

ANSWERED AT 28/03/2020 - 10:19 AM


QUESTION POSTED AT 28/03/2020 - 10:19 AM

Is hunting a form of artificial selection?

Yes hunting is a form of artificial selection.

ANSWERED AT 28/03/2020 - 10:16 AM


QUESTION POSTED AT 28/03/2020 - 10:16 AM

Scientists believe that the first life forms to appear on planet Earth were probably similar to which modern organisms?

True they do believe that

ANSWERED AT 27/03/2020 - 12:57 PM


QUESTION POSTED AT 27/03/2020 - 12:57 PM

Genetically engineered crops have been created which are more resistant to insect infestations than ordinary crops. Which of the following is a likely impact of the introduction of these crops? A. Crop yields will decrease. B. Insect populations will increase. C. More sources of water will be available. D. Fewer pesticides will enter the environment. 2. Cloning of organisms would allow scientists to complete experiments without having to account for genetic variation. Which of the following is an ethical boundary scientists must take into account in these experiments? A. Whether human cloning is acceptable in any form. B. How cloned animals are affected by their environments. C. Whether cloned plants have the same needs as other plants. D. How the genetic code of cloned organisms differs from other organisms.

Which of the following is a likely impact of the introduction of these crops?
D. Fewer pesticides will enter the environment - because the crops are genetically modified to prevent insects from consuming them, therefore the need for pesticides will lessen.  

2. Which of the following is an ethical boundary scientists must take into account in these experiments?
D. How the genetic code of cloned organisms differs from other organisms - scientists must ensure that codes of genetically modified organisms are totally different from the original organisms they are cloning.

ANSWERED AT 27/03/2020 - 09:40 AM


QUESTION POSTED AT 27/03/2020 - 09:40 AM

Explain how there are over 4 billion possible comBinations for offspring variation

Many organisms may mate and their are many types of species of organisms

ANSWERED AT 26/03/2020 - 03:27 PM


QUESTION POSTED AT 26/03/2020 - 03:27 PM

What gas is changed by some bacteria into a form that plants can use?

Nitrogen (N2) is the gas changed by some bacteria into a form a plant can use . 

ANSWERED AT 26/03/2020 - 03:15 PM


QUESTION POSTED AT 26/03/2020 - 03:15 PM

The type of fossil fuel that forms only from the remains of plants is

Coal! it's formed over years from decayed vegetation

ANSWERED AT 26/03/2020 - 01:53 PM


QUESTION POSTED AT 26/03/2020 - 01:53 PM

Loess helps to form fertile soil true or false

Its TRUE that Loess helps to form fertile soil.

ANSWERED AT 26/03/2020 - 01:22 PM


QUESTION POSTED AT 26/03/2020 - 01:22 PM

Just need a simple Yes or No. Do fungus like protists form cell walls?

Yes but the cell walls are composed differently. Protists cell walls contains cellulose and Fungi have chitin instead

ANSWERED AT 26/03/2020 - 12:52 PM


QUESTION POSTED AT 26/03/2020 - 12:52 PM

Which cell structure forms a barrier around a eukaryotic or prokaryotic cell

Its the Cell Membrane

ANSWERED AT 26/03/2020 - 12:33 PM


QUESTION POSTED AT 26/03/2020 - 12:33 PM

Alkali metals react violently with water to form metal ions, hydroxide ions, and

Alkali metals displace Hydrogen from H2O in order to make the Hydroxide ion, the displaced Hydrogen is formed as H2 gas.

ANSWERED AT 26/03/2020 - 11:45 AM


QUESTION POSTED AT 26/03/2020 - 11:45 AM

One of the many unique properties of water is that its solid form (ice) is less dense than its liquid form. Most substances become more dense when in solid form, because their molecules are more tightly compact. Why is this property of water so important to life on Earth?

The presence of hydrogen bond is one factor that explains the fact that ice floats over water because it has less density.

Due to this, rivers and lakes freeze from the surface whereas it is in liquid state at the bottom which allows the sea animals to survive even in colder temperatures.

Water makes up at least 70% of earth and 65% of our bodies and this property of water is essential for our lives as it maintains the survival.


ANSWERED AT 26/03/2020 - 11:22 AM


QUESTION POSTED AT 26/03/2020 - 11:22 AM

17. How is ozone formed?

An Ozone is formed when heat and sunlight cause chemical reactions between oxides of nitrogen and Volatile organic compounds which are also known as Hydrocarbons.

ANSWERED AT 26/03/2020 - 11:02 AM


QUESTION POSTED AT 26/03/2020 - 11:02 AM