All categories

3 years ago

How is polyethene formed?

2 answers:

7 0

The answer is B - The double bond on reactive ethene molecules breaks allowing them to bond with each other and form a chain.

Explanation:

Poly(ethene) is formed when several monomers of ethene (an alkene) are joined together. Ethene can take part in this type of reaction as it is has a double bond (it's unsaturated) which opens up to allow multiple monomers to form a chain. This reaction occurs when ethene is heated and put under pressure in the presence of a catalyst.

lana [24]3 years ago

4 0

Answer:

Explanation:

because 2× is strong. hydrogen will be remove

You might be interested in

What is the boiling point of gold 1064.43°C 2970°C 1313°C 3266°C

Vikentia [17]

Answer:

The melting point of Gold is 1064.43 degrees celsius and the boiling point is 2807 degrees celsius.

8 0

4 years ago

Read 2 more answers

3. Which of these is a function of the blood?

BaLLatris [955]

There are no answer choices therefore I cannot help you

3 0

4 years ago

Zinc reacts with hydrochloric acid according to the reaction equation Zn ( s ) + 2 HCl ( aq ) ⟶ ZnCl 2 ( aq ) + H 2 ( g ) How ma

REY [17]

Answer:

34.7mL

Explanation:

First we have to convert our grams of Zinc to moles of zinc so we can relate that number to our chemical equation.

So: 6.25g Zn x (1 mol / 65.39 g) = 0.0956 mol Zn

All that was done above was multiplying the grams of zinc by the reciprocal of zincs molar mass so our units would cancel and leave us with moles of zinc.

So now we need to go to HCl!

To do that we multiply by the molar coefficients in the chemical equation:

$\frac{0.0956g Zn}{1 } (\frac{2 mol HCl}{1molZn})$

This leaves us with 2(0.0956) = 0.1912 mol HCl

Now we use the relationship M= moles / volume , to calculate our volume

Rearranging we get that V = moles / M

Now we plug in: V = 0.1912 mol HCl / 5.50 M HCl

V= 0.0347 L

To change this to milliliters we multiply by 1000 so:

34.7 mL

7 0

4 years ago

A certain substance X condenses at a temperature of 123.3 degree C . But if a 650. g sample of X is prepared with 24.6 g of urea

Pavel [41]

Answer:

The molal boiling point elevation constant is 1.59 ≈ 1.6 $Kkgmol^{-1}$

Explanation:

To solve this question , we will make use of the equation ,

Δ $T_{b} = i*K_{b} *m$

where ,

Δ $T_{b}$ is the change in boiling point of the substance $X$ ( ° $C$ or $K$ )

$i$ is the Vant Hoff Factor which = 1 in this case ( no unit )

$K_{b}$ is the mola boiling point elevation constant of X ( $Kkgmol^{-1}$ )

$m$ is the molality of the solution which has $(NH_{2})_{2} CO$ as the solute and $X$ as the solution ( $molkg^{-1}$ )

Δ $T_{b}$ = $124.3 -123.3 = 1$ ° $C$ or $K$ ;
$i$ =1;
$m$ = $\frac{moles of solute}{weight of solvent(kg)}$ $molkg^{-1}$

∴ $m = \frac{\frac{24.6}{60} }{\frac{650}{1000} }$

as the weight of $(NH_{2})_{2} CO$ is $60g$ and thus number of moles = $\frac{24.6}{60}$

and the weight of solvent in $kg$ is $\frac{650}{1000}$

4. $K_{b}$ ⇒ ?

∴

$1=1*K_{b} *\frac{\frac{24.6}{60} }{\frac{650}{1000} }$

⇒ $K_{b}$ = $1.59$ ≈ 1.6 $Kkgmol^{-1}$

4 0

3 years ago

A fossilized bone contains about 65% of its original carbon-14. to the nearest hundred years, how old is the bone

Assoli18 [71]

3600 years.
Since 65% of the carbon-14 is remaining, we need to get the logarithm to base 2 of 0.65 to determine how many half lives have expired. So: log(0.65)/log(2) = -0.187086643/0.301029996 = -0.621488377
So we know that 0.621488377 half-lives has gone by to the bone sample. Now we just need to multiply by the half-life of carbon-14 which is 5730 years. So: 0.621488377 * 5730 = 3561.128399 years.  Rounding to the nearest 100 years gives us 3600 years.

7 0

3 years ago