A certain substance melts at a temperature of . But if a sample of is prepared with of urea dissolved in it, the sample is found to have a melting point of instead. Calculate the molal freezing point depression constant of . Round your answer to significant digits.

Answers

Answer 1

Answer:

Answer:

2.2 °C/m

Explanation:

It seems the question is incomplete. However, this problem has been found in a web search, with values as follow:

" A certain substance X melts at a temperature of -9.9 °C. But if a 350 g sample of X is prepared with 31.8 g of urea (CH₄N₂O) dissolved in it, the sample is found to have a melting point of -13.2°C instead. Calculate the molal freezing point depression constant of X. Round your answer to 2 significant digits. "

So we use the formula for freezing point depression:

ΔTf = Kf * m

In this case, ΔTf = 13.2 - 9.9 = 3.3°C

m is the molality (moles solute/kg solvent)

350 g X ⇒ 350/1000 = 0.35 kg X

31.8 g Urea ÷ 60 g/mol = 0.53 mol Urea

Molality = 0.53 / 0.35 = 1.51 m

So now we have all the required data to solve for Kf:

ΔTf = Kf * m

3.3 °C = Kf * 1.51 m

Kf = 2.2 °C/m

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What is the role of the judicial branch?to interpret laws
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Answers

Answer:

to interpret laws

Explanation:

Answer:

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Explanation:

Find the product.
(n + 8)(n - 2)
n2- 6n - 16
n2+ 6n - 16
n2- 6n + 16

Answers

Answer:The product of the given expression is : $n^2+6n-16$

Explanation:

Given expression:(n + 8)(n - 2)

Using identity: $(a+b)(a+c)=a^2+(b+c)a+bc$

a = n, b=8, c= (-2)

$n^2+(8+(-2))n+(8)(-2)$

$n^2+6n-16$

The product of the given expression is : $n^2+6n-16$

Answer : The product of the given expression is:

$n^2+6n-16$

Explanation :

The given expression is:

$(n+8)(n-2)$

First we have to open the bracket by multiplying the terms.

$n^2-2n+8n-16$

Now we are adding like terms.

$n^2+6n-16$

Hence, the product of the given expression is, $n^2+6n-16$

Why is butanol not a hydrocarbon?

Answers

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Complete the equation Fe + HOH = ?

Answers

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Answer:

Fe+2HOH=Fe(OH)_2+H_2. Iron is divalent to hydrogen and water.

Explanation:

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Answers

the only way i could see the difference

The atom in a sample of an element must contain nuclei with the same number of?

Answers

Hey there!

Answer: Protons

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Thank you!

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