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3 years ago

AssignmentExplain why it is not advisable to wearblack silky cloth in the sun

Chemistry

1 answer:

Crazy boy [7]3 years ago

3 0

Answer:

It is not water absorbant and also the colour black, due to it's dark nature makes the person wearing the cloth feel hot. Unlike cotton, silk is not at all water absorbant as it does not absord any sweat produced in the wearers body

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The following chemical reactants produce the ester ethyl ethanoate (C4H8O2): C2H6O + CH3COOH What type of reaction occurs to mak

nydimaria [60]

Answer:

Esterification reaction

Explanation:

An esterification reaction is an organic reaction involving an organic acid and an alkanol to give an ester or an ethanoate and water

Like the name suggests, an ester is the product formed in an esterification reaction alongside water. It is like a neutralization reaction but this time it solely contains organic molecules. These molecules react with each other to give rise to another organic molecule which is a member of a different homologous series.

Practically, to form ethyl ethanoate, ethanoic acid react with ethanol in the presence of concentrated sulphuric acid which catalyses the reaction.

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4 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.

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

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3 years ago

Why do we need to be more careful of how we use our water

Reil [10]

That's why it's important for you to use water wisely and not to waste it. When you waste water, you're taking water that other people might need. But when you use water carefully, you leave more water for other people to use. It is also important to use water carefully because our weather can be unpredictable.

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3 years ago

Read 2 more answers

The active form of vitamin D is called ________.

alexandr1967 [171]

<span>Calcitriol </span>is the active form of vitamin D. (D)

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3 years ago

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How do a strong electrolyte, weak electrolyte, and non-electrolyte differ in the number of ions each produces when dissolved in

Dmitrij [34]

Strong electrolytes are completely ionised in solution.
Weak ones are only partially ionised.
Non electrolytes do not form ions