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3 years ago

After chlorofluorocarbons we’re banned, which class of chemicals was used in their place

Chemistry

2 answers:

Damm [24]3 years ago

8 0

Answer:

Hydrofluorocarbons

Explanation:

Law Incorporation [45]3 years ago

3 0

Answer:

Hydrofluorocarbons

Explanation:

Earlier chlorofluorocarbons were used for refrigeration purpose. But they were banned as they were primary cause of ozone depletion.

In order to replace chlorofluorocarbons, now hydrofluorocarbons are used which helps to protect earth from stratospheric ozone-depleting substances.

The difference between chlorofluorocarbons and hydrofluorocarbons is of hydrogen. In hydrofluorocarbons one of the halogen is being replaced by hydrogen.

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How many atoms in the pictured molecule can form hydrogen bonds with water molecules?

ddd [48]

Answer:

3

Explanation:

Please, find the image with the pictured molecule for this question attached.

The molecule has one oxygen atom (red) covalently bonded to one hydrogen atom (light grey), one nitrogen atom (blue) covalently bonded to two hydrogen atoms (light grey), and two carbon atoms (dark grey) bonded each to two hydrogen atoms (light grey).

Hydrogen bondings are intermolecular bonds (bonds between atoms of two different molecules not between atoms of the same molecule). The hydrogen bonds are attractions between the positive end of one hydrogen atom and the negative end of a small atom of other molecule (N, O, or F).

Since, nitrogen and oxygen are much more electronegative than hydrogen atoms, you conclude that:

The two hydrogen atoms covalently bonded to the nitrogen atoms have considerably partial positive charge.

The hydrogen atom covalently bonded to the oxygen atom also has a a relative large partial positive charge.

So, those are three ends of the molecule that can form hydrogen bonds with water molecules.

The hydrogen bondings are only possible when hydrogen is covalently bonded to N, O or F atoms.

4 0

3 years ago

Create a balanced equation of this COMBUSTION REACTION: C8H18 (hint, all combustion reactions have some things in common (CO2 an

julsineya [31]

2C8H18+72O2>>16CO2+36H2O<< balanced

8 0

3 years ago

Calculate the initial rate for the formation of c at 25 ∘c, if [a]=0.50m and [b]=0.075m

Nataly_w [17]

The rate of formation of a product depends on the the concentrations of the reactants in a variable way.

If two products, call them A and B react together to form product C, a general equation for the formation of C has the form:

rate = k*[A]^m * [B]^n

Where the symbol [ ] is the concentration of each compound.

Then, plus the concentrations of compounds A and B you need k, m and n.

Normally you run controled trials in lab which permit to calculate k, m and n .

Here the data obtained in the lab are:

Trial [A] [B] Rate 
 (M) (M) (M/s) 
1 0.50 0.010 3.0×10−3 
2 0.50 0.020 6.0×10−3 
3 1.00 0 .010 1.2×10−2

Given that for trials 1 and 2 [A] is the same you can use those values to find n, in this way

rate 1 = 3.0 * 10^ -3 = k [A1]^m * [B1]^n

rate 2 = 6.0*10^-3 = k [A2]^m * [B2]^n

divide rate / rate 1 => 2 = [B1]^n / [B2]^n

[B1] = 0.010 and [B2] = 0.020 =>

6.0 / 3.0 =( 0.020 / 0.010)^n =>

2 = 2^n => n = 1

Given that for data 1 and 3 [B] is the same, you use those data to find m

rate 3 / rate 1 = 12 / 3.0 = (1.0)^m / (0.5)^m =>

4 = 2^m => m = 2

Now use any of the data to find k

With the first trial: rate = 3*10^-3 m/s = k (0.5)^2 * (0.1) =>

k = 3.0*10^-3 m/s / 0.025 m^3 = 0.12 m^-2 s^-1

Now that you have k, m and n you can use the formula of the rate with the concentrations given

rate = k[A]^2*[B] = 0.12 m^-2 s^-1 * (0.50m)^2 * (0.075m) = 0.0045 m/s = 4.5*10^=3 m/s

Answer: 4.5 * 10^-3 m/s

8 0

3 years ago

Read 2 more answers

Write a balanced chemical equation for the synthesis of ammonia from its elements including the word energy as a product

Katen [24]

Ammonia synthesis can be done by Haber process. N₂ gas and H₂ gas are used as the reactants. The balanced reaction equation is
N₂(g) + 3H₂(g) ⇄ 2NH₃(g) + energy

This is a reversible process and the conditions as follows,
1. Pressure should be 150 - 200 atm
2. Temperature is between 450 - 500 °C
3. Catalyst is iron

5 0

3 years ago

Which of these is a chemical property?

Katyanochek1 [597]

Yes, refer to the previous answer.

6 0

3 years ago

Read 2 more answers