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2 years ago

Based on the kinetic molecular theory (KMT), which statement is true?

Chemistry

1 answer:

nataly862011 [7]2 years ago

5 0

Statement 1 is false because heat is the movement of molecules.

Statement 2 is true because matter is composed of elementary particles which are VERY small.

Statement 3 is false because the kinetic energy of a particle determines its heat and it is impossible for a particle to be completely motionless.

Statement 4 is false because neutrons do not have a charge and make up a large portion of all matter.

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3. Which of the following sentences apply to neutrons? a. have a negative charge. b. circle around the atom nucleus. c. are the

DerKrebs [107]

Answer:

d.have a mass of 1 amu..

Explanation:

Does not match a as the answer for a is electrons B.electron circle around the nucleus because neutrons are inside the nucleus.C.proton and neutrons make the nucleus so the only answer left is .d .which is correct

3 0

2 years ago

natural selection is an example of a mechanism of evolution does this mechanism produce a change in individuals or populations e

skad [1K]

Answer: Yes, Natural selection is natures way of making the fittest and top dogs of the food chain, It can produce a change in individuals and populations by completely reducing or wiping out a population not fit for survival in its inviroment and can even force a change of the creature to make it able to survive.

Example: would be rabbits, a snow rabbit wouldn't survive very well in the desert and a jack rabbit wouldn't be able to survive in the cold winter due to temp and the fact that predators like wolves would be able to spot it easier from its color of its fur.

Note: Hope this helps, and I hope this is want it was asking. Good luck :)

8 0

3 years ago

Give the direction of the reaction, if K >> 1. Give the direction of the reaction, if K >> 1. The forward reaction i

anygoal [31]

Answer:

A. for K>>1 you can say that the reaction is nearly irreversible so the forward direction is favored. (Products formation)

B. When the temperature rises the equilibrium is going to change but to know how is going to change you have to take into account the kind of reaction. For endothermic reactions (the reverse reaction is favored) and for exothermic reactions (the forward reaction is favored)

Explanation:

A. The equilibrium constant K is defined as

$K=\frac{Products}{reagents}$

In any case

aA +Bb equilibrium Cd +dD

where K is:

$K= \frac{[C]^{c}[D]^{d}}{[A]^{a}[B]^{b}}$

[] is molar concentration.

If K>>> 1 it means that the molar concentration of products is a lot bigger that the molar concentration of reagents, so the forward reaction is favored.

B. The relation between K and temperature is given by the Van't Hoff equation

$ln(\frac{K_{1}}{K_{2}})=\frac{-delta H^{o}}{R}*(\frac{1}{T_{1}}-\frac{1}{T_{2}})$

Where: H is reaction enthalpy, R is the gas constant and T temperature.

Clearing the equation for $K_{2}$ we get:

$K_{2}=\frac{K_{1}}{e^{\frac{-deltaH^{o}}{R}*(\frac{1}{T_{1}} -\frac{1}{T_{2}})}}$

Here we can study two cases: when delta $H^{o}$ is positive (exothermic reactions) and when is negative (endothermic reactions)

For exothermic reactions when we increase the temperature the denominator in the equation would have a negative exponent so $K_{2}$ is greater that $K_{1}$ and the forward reaction is favored.

When we have an endothermic reaction we will have a positive exponent so $K_{2}$ will be less than $K_{1}$ the forward reactions is not favored.

${e^{\frac{-deltaH^{o}}{R}*(\frac{1}{T_{1}} -\frac{1}{T_{2}})}}$

5 0

3 years ago

Water is known as the universal solvent. One reason water makes a good solvent is because it is composed of polar molecules. Wha

Flauer [41]

Answer: Option (C) is the correct answer.

Explanation:

A water molecule is made up of two hydrogen atoms and one oxygen atom. Its molecular formula is $H_{2}O$ .

It is known that hydrogen is electropositive in nature whereas oxygen is electronegative in nature. Therefore, oxygen will pull the electron of hydrogen towards itself as a result, there will be formation of partial positive charge on hydrogen and partial negative charge on oxygen atom.

Thus, the water molecule becomes polar. So, we can conclude that water molecule is a polar molecule because water molecules have a positive charge on one end and a negative charge on the other.

5 0

2 years ago

The aldol reaction is catalyzed by acid as well as base. What is the reactive nucleophile in the acid-catalyzed aldol reaction

svp [43]

Answer:

The reactive nucleophile is Ketone.

Explanation:

In organic chemistry, The process of acid - catalyzed aldol condensation starts from when ketone (or any aldehyde) is converted to an -enol, after which it attacks another ketone/aldehyde that has already been activated by parbonyl oxygen protonation.

The process of this is that first of all the ketone undergoes tautomerization to form -enol. Thereafter, the other carbonyl will undergo protonation which makes the carbon activated towards attack. Now, the nucleophilic enol will be added to the carbonyl in a [1,2]-addition reaction and we will now use deprotonation to obtain the neutral Aldol product.

Now, since only the ketone can produce an -enol, thus it is the nucleophile as aldehydes are better electrophiles

4 0

2 years ago