All categories

3 years ago

Write short note on

Chemistry

2 answers:

irakobra [83]3 years ago

8 0

Answer:

Steam distillation is a separation process which purifies isolate temperature-sensitive materials, such as natural aromatic compounds. In steam distillation, dry steam is passed through the plant material. These vapours undergo condensation and collection in receivers.

distillation under pressure is used for the purification of those substance which get decompose on their boiling point. so , a suction pump (vaccum) is fitted with a beaker in order to lower it's pressure, due to which boiling pressure decreases. so that it can be distilled of before reaching to its boiling point.

Fractional distillation is a type of distillation which involves the separation of miscible liquids. The process involves repeated distillations and condensations and the mixture is usually separated into component parts. The separation happens when the mixture is heated at a certain temperature where fractions of the mixture start to vaporize.

Explanation:

HOPE IT HELPS YOU

WITCHER [35]3 years ago

4 0

I hope it helps you ❤️❤️❤️❤️

You might be interested in

harry potter flips a coin (not magical ) 8 times. He gets heads 1 time. What are the odds that his next flip will be heads? A 10

rodikova [14]

C. 50%
Unless the question is saying he only gets heads once, in which case it would be 0%. Or the coin could have 2 heads. Then it would be 100%.
But I'm pretty sure it's 50%.

7 0

2 years ago

A cell is placed in a salt solution that has the same concentration as the inside of the cell. What will happen to the cell?

nata0808 [166]

Answer:

Explanation:

4 0

3 years ago

In a certain industrial process involving a heterogeneous catalyst, the volume of the catalyst (in the shape of a sphere) is 10.

olga nikolaevna [1]

Answer:

a. The second run will be faster.

d. The second run has twice the surface area.

Explanation:

The rate of a reaction is proportional to the surface area of a catalyst. Given the volume (V) of a sphere, we can find its surface area (A) using the following expression.

$A=\pi ^{1/3} (6V)^{2/3}$

The area of the 10.0 cm³-sphere is:

$A=\pi ^{1/3} (6.10.0)^{2/3}=22.4cm^{2}$

The area of each 1.25 cm³-sphere is:

$A=\pi ^{1/3} (6. 1.25)^{2/3}=5.61cm^{2}$

The total area of the 8 1.25cm³-spheres is 8 × 5.61 cm² = 44.9 cm²

The ratio of 8 1.25cm³-sphere to 10.0 cm³-sphere is 44.9 cm²/22.4 cm² = 2.00

Since the surface area is doubled, the second run will be faster.

6 0

3 years ago

Consider 2H2 + O2 → 2H2O. To produce 1.2 g water, how many grams of H2 are required? Report to the correct number of significant

Elden [556K]

Answer:

0.133 mol (corrected to 3 sig.fig)

Explanation:

Take the atomic mass of H=1.0, and O=16.0,

no. of moles = mass / molar mass

so no. of moles of H2O produced = 1.2 / (1.0x2+16.0)

= 0.0666666 mol

From the equation, the mole ratio of H2:H2O = 2:2 = 1:1,

meaning every 1 mole of H2 reacted gives out 1 mole of water.

So, the no, of moles of H2 required should equal to the no, of moles of H2O produced, which is also 0.0666666 moles.

mass = no. of moles x molar mass

hence,

mass of H2 required = 0.066666666 x (1.0x2)

= 0.133 mol (corrected to 3 sig.fig)

3 0

3 years ago

Calculate the change in enthalpy for the following reaction, using the bond enthalpy data provided below. (Note: you may round t

aliina [53]

Answer:

-514 kJ/mol

Explanation:

The bond enthalpy which is also known as bond energy can be defined as the amount of energy needed to split one mole of the stated bond. The change in enthalpy of a given reaction can be estimated by subtracting the sum of the bond energies of the reactants from the sum of the bond energies of the products.

For the given chemical reaction, the change in enthalpy of the reaction is:

Δ $H_{rxn} =$ [2(409) + 4(388) + 3(496) - 4(630) - 4(463)] kJ/mol = 818 + 1552 + 1488 - 2520 - 1852 = -514 kJ/mol

3 0

3 years ago