All categories

2 years ago

What is a change in which energy is released is called

Chemistry

1 answer:

inessss [21]2 years ago

4 0

Answer: Chemical Reactions

Explanation:

Chemical reactions often involve changes in energy due to the breaking and formation of bonds.

You might be interested in

If 200 g of benzoyl peroxide are used with 38 Kg of PTFE monomer, calculate the expected molecular weight of the polymer if (i)

den301095 [7]

Explanation:

The molecular weight of benzoyl peroxide is 242.23 g/mol.

Therefore, number of moles present in 200 g of benzoyl peroxide are as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{200 g}{242.23 g/mol}$

= 0.825 mol

Molecular weight of PTFE is 100 g/mol.Hence, calculate the number of moles of PTFE in 38 kg as follows.

As 1 kg = 1000 g. So, 38 kg = 38000 g.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{38000 g}{100 g/mol}$

= 380 mol

As it is given that the initiator is 15% active. So, actual number of moles of benzoyl peroxide are as follows.

$0.15 \times 0.826$

= 0.124 mol

For combination, 1 mol of benzoyl peroxide produces 1 chain. Therefore, degree of polymerization will be calculated as follows.

DP = $\frac{380 mol}{0.124 mol}$

= 3065.33 mol

Average molecular weight of monomer is as follows.

$\frac{0.124}{0.124 + 380} \times MW_{benzoyl} + \frac{380}{0.124 + 380} \times MW_{PTFE}$

= 100.05 g/mol

Therefore, calculate the expected molecular weight of polymer as follows.

$3065.33 \times 100.05 g/mol$

= 306675.23 g/mol

Hence, for disproportion 1 mole benzoyl peroxide produces 2 chains.

DP = $\frac{2 \times 380}{0.124}$

= 6129.03

Therefore, calculate the expected polymer weight as follows.

$6129.03 \times 100.05$

= 613209.68 g/mol

Thus, we can conclude that the the expected polymer weight is 613209.68 g/mol.

6 0

3 years ago

The edge of the card measures 2.5 inches, what is it in cm?

Citrus2011 [14]

Answer:

6.35 centimeters

Explanation:

2.5 inches = 6.35 centimeters

Formula:

multiply the value in inches by the conversion factor '2.54'.

So, 2.5 inches = 2.5 × 2.54 = 6.35 centimeters.

4 0

1 year ago

Describe two tests that you can run to determine if something is a substance or a mixture.

ryzh [129]

The difference between a substance and a mixture is that a substance is one of a kind, a material of the same composition throughout, on the contrary, a mixture is one or more different substances brought together and mixed together without changing the nature of each single substance.

One way to test it is to take two substances like sand and table salt. They should each be in granular form and in adequate amount to mix. Neither substance has changed after mixing the two. Even though it may not be easy or convenient to accomplish, each substance could be separated out from the mixture.

When it comes to two substances in lump form, it would not be a mixture when one lump is positioned next to the other lump because there are not enough pieces to combine.

However, there could be a mixture of three substances, like sand, table salt and graphite powder and there could be a mixture with four substances, etc., ad infinitum.

Mixtures are of solid substances in general. On the other hand, one starts referring to solutions when liquids are involved. Gases can be a mixture like for example, air is a mixture with nitrogen, oxygen, argon, etc.

4 0

2 years ago

Determine the [H3O+] in a 0.265 M HClO solution. The Ka of HClO is 2.9 × 10-8.

dexar [7]

8.8 × 10-5 M is the [H3O+] concentration in 0.265 M HClO solution.

Explanation:

HClO is a weak acid and does not completely dissociate in water as ions.

the equation of dissociation can be written and ice table to be formed.

HClO +H2O ⇒ ClO- + H3O+

I 0.265 0 0

C -x +x +x

E 0.265-x +x +x

Now applying the equation of Ka, where Ka is given as 2.9 × 10-8.

Ka = $\frac{[ClO-][H3O+]}{[HClO]}$

2.9 × 10^-8 = $\frac{[x] [x]}{[0.265-x]}$

$x^{2}$ = 7.698 x $10^{-9}$

x = 8.8 × 10-5 M

The hydronium ion concentration is 8.8 × 10-5 M in 0.265 M solution of HClO.

8 0

2 years ago

If the same materials are used to build a voltaic cell and an electrolytic cell, how would the chemical reactions compare?

nadya68 [22]

In the electrolytic cell, depending on the polarity of the battery, either a more vigorous reaction (though the same as the voltaic cell) would occur, or the reverse would.

3 0

3 years ago