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igomit [66]
3 years ago
9

In a recrystallization (a technique that you will encounter later in the semester), a solid is dissolved in a solvent and later

the solvent is removed. if a mp of the sample is taken while the sample is still moist with solvent, what effect would that have on the mp of the sample?
Chemistry
1 answer:
grandymaker [24]3 years ago
7 0

In a recrystallization (a technique that you will encounter later in the semester), a solid is dissolved in a solvent and later the solvent is removed. if a mp of the sample is taken while the sample is still moist with solvent then melting point will not come out to be accurate, as solvent is still present in the compound and that results in the variation of the melting point as the residual solvent will serves as impurities , and due to the presence of these impurities, melting point vary and does not come to be accurate .

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Iron(II) chloride is formed from the reaction between iron and copper(II) chloride. Fe + CuCl2 FeCl2 + Cu If the reactants have
elena55 [62]

Answer: see figure attached and explanation below.

Explanation:

1) Chemical equation (given):

Fe + CuCl₂ → Cu + FeCl₂

2) ΔHf reactants: -256 kJ/mol (given)

3) ΔHf products: - 321 kJ/mol (given)

4) ΔH reaction = ΔHf products - ΔHf reactants = - 321 kJ/mol - (- 256 kJ/mol) = - 65 kJ/mol

5) Conclusion:

i) Since ΔHf of products is less (more negative) than ΔHf of reactants, the reaction is exhotermic: the reaction released energy, which is the reason why the products content less potential energy than the reactants.

ii) Then, the energy diagram is the typical one of an exothermic reaction: the products start a certain potential energy level, the energy incrases until reaching the activation energy (the energy barrier to form the activated complex) and then energy decreases until a level below the energy of the reactants.

iii) See the attached figure with such kind of diagram showing the products at a lower level than the reactans

3 0
3 years ago
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Dmitry [639]

Answer:

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8 0
2 years ago
Fill in the blank for the following statement: ________ is the movement of rocks, sand, or materials from a place?
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Explanation:

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Please Help!
Whitepunk [10]

We can use two equations for this problem.<span>

t1/2 = ln 2 / λ = 0.693 / λ
Where t1/2 is the half-life of the element and λ is decay constant.

20 days = 0.693 / λ 
λ   = 0.693 / 20 days        (1) 

Nt = Nο eΛ(-λt)                (2)

Where Nt is atoms at t time, No is the initial amount of substance, λ is decay constant and t is the time taken.
t = 40 days</span>

<span>No = 200 g

From (1) and (2),
Nt =  200 g eΛ(-(0.693 / 20 days) 40 days)
<span>Nt = 50.01 g</span></span><span>

</span>Hence, 50.01 grams of isotope will remain after 40 days.

<span>
</span>

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Which is heavier? 30kg or 60lb?
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