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disa [49]
3 years ago
9

How many kilojoules are released when 8.2 g of water condenses at 100 °c and cools to 15 °c?

Chemistry
1 answer:
MrRa [10]3 years ago
3 0

Answer:- 2.92 kJ of heat is released.

Solution:- We have water at 100 degree C and it's going to be cool to 15 degree C.

So, change in temperature, \Delta T = 15 - 100 = -85 degree C

mass of water, m = 8.2 g

specific heat of water, c = 4.184\frac{J}{^0C.g}

The equation used for solving this type of problems is:

q=mc\Delta T

Let's plug in the values in the equation and solve it for q which is the heat energy:

q = (8.2)(4.184)(-85)

q = -2916.248 J

They want answer in kJ. So, let's convert J to kJ and for this we divide by 1000.

q=-2916.248J(\frac{1kJ}{1000J})

q = -2.92 kJ

Negative sign indicates the heat is released. So, in the above process of coiling of water, 2.92 kJ of heat is released.

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amm1812

Answer:

All of the above are true

Explanation:

a) The emission spectrum of a particular element is always the same and can be used to identify the element: It's true since the emission spectrum for each element is unique. It has the same bright lines at the same wavelength. This feature is used to identify elements. For example, the study of the emission spectra of light arriving from stars allow us to identify the elements presents in the star because the light contains the emission spectra of those elements.

b)The uncertainty principle states that we can never know both the exact location and speed of an electron:  It is true since the velocity of an electron is related to its wave nature, while its position is related to its particle nature and we cannot simultaneously measure electron's position and velocity with precision.

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5 0
3 years ago
How does solubility differ between small versus large carbohydrates? Explain.
EleoNora [17]

Answer with Explanation:

Small and large carbohydrates have<em> diverse structural properties</em>. Such property allow them to have <u>different solubility.</u>

Solubility is a chemical property of a substance that allows it to dissolve in a given solvent.

Carbohydrates are made up of "monosaccharides." These are simple sugars and are considered small carbohydrates. On the contrary, "polysaccharide" is an example of a large carbohydrate.<em><u> Monosaccharides are soluble in water</u></em><em> </em>while<em><u> many polysaccharides are not soluble in water.</u></em>

The high solubility of monosaccharides is mainly due to the presence of hydroxide (OH) groups. These groups are always ready to bond with water (H₂O). Many polysaccharides are not soluble in water because of <em>intermolecular interactions</em> that prevents it from binding with water. Its dissolution process is different when compared to the smaller molecules.

So, this explains the answer.

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3 years ago
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Answer:

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The reaction of Lucas reagent reacts with alcohols leading to the formation of an alkyl chloride. Since the reaction proceeds via a carbocation mechanism, tertiary alcohols give an immediate reaction. Once a tertiary alcohol is mixed with Lucas reagent, the solution turns cloudy almost immediately indicating an instant positive reaction.

Secondary alcohols may turn cloudy within five minutes of mixing the solutions. Primary alcohols do not significantly react with Lucas reagent obviously because they do not form stable carbocations.

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