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3 years ago

For each example of a phase change, identify whether heat is absorbed from the surroundings or

Chemistry

1 answer:

vladimir1956 [14]3 years ago

4 0

In case of popsicle and alcohol, heat is absorbed from the surrounding.

In case of lava heat is emitted into the surrounding.

<h3><u>Explanation:</u></h3>

Melting of popsicle is just a change of state from solid to liquid. This is the phenomenon which occurs when the popsicle gets the heat from the surrounding and it absorbs the heat, thereby turning into liquid. So it absorbs heat from the surrounding.

The alcohol when spread on the skin evaporates into vapour. This is the phenomenon of evaporation which occurs when alcohol absorbs heat from the surrounding and thereby turning into vapour.

Similarly, when lava solidifies into solid, the change of state occurs. As lava emits heat into the surrounding, the temperature of the lava goes down, thereby changing it into solid. So it emits heat into surrounding.

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A phosphorus atom and a chlorine atom are likely to form a covalent bond because both elements:

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Read 2 more answers

Suppose 550.mmol of electrons must be transported from one side of an electrochemical cell to another in 49.0 minutes. Calculate

nekit [7.7K]

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18.0 Ampere is the size of electric current that must flow.

Explanation:

Moles of electron , n = 550 mmol = 0.550 mol

1 mmol = 0.001 mol

Number of electrons = N

$N=N_A\times n$

Charge on N electrons : Q

$Q = N\times 1.602\times 10^{-19} C$

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1 min = 60 seconds

Size of current : I

$I=\frac{Q}{T}=\frac{N\times 1.602\times 10^{-19} C}{49.0\times 60 seconds}$

$=\frac{n\times N_A\times 1.602\times 10^{-19} C}{49.0\times 60 seconds}$

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The aldol condensation involves nucleophilic attack of an enolate to a carbonyl. Use the pop-up menus to identify the total numb

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Aldol condensation involves the reaction of an acid or base with a carbonyl group producing a nucleophile that attacks another carbonyl compound to yield a β-hydroxyaldehyde or β-hydroxyketone compound.

<h3>What is aldol condensation?</h3>

The aldol condensation is a reaction in organic chemistry in which there is a reaction between an acid or base and a carbonyl group which then serves as the nucleophile that attcks a second carbonyl to yield a β-hydroxyaldehyde or β-hydroxyketone compound.

The aldol condensation may be acid catalysed or base catlysed. The question is incomplete hence the complete mechanimsms can not be decuced.

Learn more about aldol condensation: brainly.com/question/9415260

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Answer:

Explanation:

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