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3 years ago

Give reason:

Chemistry

1 answer:

Darya [45]3 years ago

6 0

Answer:

a.The glass beads present in the fractionating column provide a large surface area for hot vapours to cool and condense repeatedly

b.Crystallization is better than evaporation because some solids can decompose or can get burned during evaporation

Explanation:

a.The fractionating column is fitted in the neck of the distillation flask containing the mixture of liquids to be separated

b. Also in some cases impurities can remain dissolved in the solution while evaporation which cannot be removed even after filtration

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This is a material that allows heat/electricity to transfer.

Anvisha [2.4K]

A material that allows heat/electricity to transfer is called a conductor.

5 0

3 years ago

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If 36 000 kg of full cream milk containing 4% fat is to be separated in a 6 hour period into skim milk with 0.45% fat and cream

Yuri [45]

Answer:

B=5522.33kg/h

C=478.11kg/h

Explanation:

Hi! It's a mass balance. First we have to determine the inflow.

mass flow rate = 36000kg / 6h = 6000kg / h

We define the input variable

- input flow (A) = 6000kg / h

-XgA = percentage of fat in A = 0.04

We define output variables.

- skim milk (B)

-creme (C)

-XgB = fat percentage at B = 0.0045

-XgC = percentage of fat in C = 0.45

Then we can start with the balance.

As a general rule, the mass balance is:

Input = Output

Balance sheet

1) A = B + C

Fat balance

2) A * XgA = B * XgB + C * XgC

Now we can solve.

We replace and clear B in equation 2

6000kg / h * 0.04 = B * 0.0045 + C * 0.45

B = (240kg / h) /0.045-C*0.45/0.0045

3) B = 53333.33kg / h-C * 100

We replace equation 3 in 1 and clear C

A = B + C

6000kg / h = 53333.33kg / h-C * 100 + C

C=(6000kg/h-53333.33kg/h)/(-99)

C=478.11kg/h

We replace C in equation 3 and calculate B

B = 53333.33kg / h-478.11kg/h * 100

B=5522.33kg/h

Then we have the values of the outflows.

C=478.11kg/h

B=5522.33kg/h

7 0

3 years ago

Three isotopes of argon occur in nature – 36 18Ar, 38 18Ar, 40 18Ar. Calculate the average atomic mass of argon to two decimal p

likoan [24]

Answer: 3) 39.96 amu

Explanation:

Mass of isotope Ar- 36 = 35.97 amu

% abundance of isotope Ar- 36= 0.337% = $\frac{0.337}{100}=3.37\times 10^{-3}$

Mass of isotope Ar- 38 = 37.96 amu

% abundance of isotope 2 = 0.063 % = $\frac{0.063}{100}=6.3\times 10^{-4}$

Mass of isotope Ar- 40 = 39.96 amu

% abundance of isotope 2 = 99.600 % = $\frac{99.600}{100}=0.996$

Formula used for average atomic mass of an element :

$\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})$

$A=\sum[(35.97\times 3.37\times 10^{-3})+(37.96\times 6.3\times 10^{-4})+(39.96\times 0.996)]$

$A=39.96amu$

Therefore, the average atomic mass of argon is 39.96 amu

4 0

3 years ago

Calculate the relative formula/atomic mass of each of the following compounds:

zmey [24]

1. HCl (H:1, Cl 35.5) ---> 1+35.5 = 36.5
2. FeS (Fe:56, S:32) ---> 56+32 = 88
3. Cl2 (Cl:35.5) ---> 35.5 x 2 = 71
4. CaC03 (Ca:40, C: 12, O: 16) ---> 40 + 12 + 3(16) = 100
5. Fe0 (Fe: 56, O: 16) ---> 56+16=72

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3 years ago

As pH increases, what happens to the hydrogen ion concentration?

levacccp [35]

Answer:

According to libretexts the answer would be B. decreases.

Explanation:

If the hydrogen concentration increases, the pH decreases, causing the solution to become more acidic. This happens when an acid is introduced. ... If the hydrogen concentration decreases, the pH increases, resulting in a solution that is less acidic and more basic

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3 years ago

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