All categories

3 years ago

Why is burning of plastics not considered a good method for their disposal?

1 answer:

6 0

Plastics release chemicals and fumes when burned which can harm the enviroment around them. A good method for their disposal would be recycling them so they can later be used as something else.

You might be interested in

You need to produce a buffer solution that has a pH of 5.50. You already have a solution that contains 10 mmol (millimoles) of a

balandron [24]

Answer:

56.9 mmoles of acetate are required in this buffer

Explanation:

To solve this, we can think in the Henderson Hasselbach equation:

pH = pKa + log ([CH₃COO⁻] / [CH₃COOH])

To make the buffer we know:

CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺ Ka

We know that Ka from acetic acid is: 1.8×10⁻⁵

pKa = - log Ka

pKa = 4.74

We replace data:

5.5 = 4.74 + log ([acetate] / 10 mmol)

5.5 - 4.74 = log ([acetate] / 10 mmol)

0.755 = log ([acetate] / 10 mmol)

10⁰'⁷⁵⁵ = ([acetate] / 10 mmol)

5.69 = ([acetate] / 10 mmol)

5.69 . 10 = [acetate] → 56.9 mmoles

6 0

3 years ago

he heat of fusion of tetrahydrofuran is . Calculate the change in entropy when of tetrahydrofuran melts at . Be sure your answer

lana [24]

Answer:

$\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}$

Explanation:

Hello.

In this case, given the heat of fusion of THF to be 8.5 kJ/mol and freezing at -108.5 °C, for the required mass of 5.9 g, we can compute the entropy as:

$\Delta S=\frac{n*\Delta H}{T}$

Whereas n accounts for the moles which are computed below:

$n=5.9g*\frac{1mol}{72g} =0.082mol$

Thus, the entropy turns out:

$\Delta S=\frac{0.0819mol*8.5 kJ/mol}{(-108.5+273.15)K}\\\\\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}$

Best regards.

3 0

3 years ago

Different microscopic organisms cause different

lozanna [386]

Answer/Explanation:

A theory has lots of scientific evidence to back it up. We know this to be true based on lots of different diseases and studies of their spread.

A hypothesis is more of a starting point - an educated guess based on limited evidence. It requires further testing before becoming a theory.

A law is something that can be generalized to lots of contexts, and is universal. Such as the law of thermodynamics.

5 0

3 years ago

With the Haber process, how many grams of hydrogen will be needed to make 0.3820 pounds of ammonia? Needed to 3 decimal places f

masya89 [10]

30.576 g of hydrogen

Explanation:

First we need to covert the pound in grams.

if 1 pound is equal to 453.592 grams

then 0.3820 pounds is equal to X grams

X = (0.3820 × 453.592) / 1 = 173.272 grams

So we have 173.272 grams of ammonia.

Now we look at the chemical reaction where hydrogen (H₂) reacts with nitrogen (N₂) to produce ammonia (NH₃):

3 H₂ + N₂ → 2 NH₃

number of moles = mass / molar weight

number of moles of ammonia = 173.272 / 17 = 10.192 moles

Now taking in account the chemical reaction, we formulate the following reasoning:

if 3 moles of hydrogen produce 2 moles of ammonia

then Y moles of hydrogen produce 10.192 moles of ammonia

Y = (3 × 10.192) / 2 = 15.288 moles of hydrogen

mass = number of moles × molar weight

mass of hydrogen = 15.288 × 2 = 30.576 g

Learn more about:

problems with number of moles

brainly.com/question/13950919

brainly.com/question/13947602

#learnwithBrainly

4 0

3 years ago

What are the period and group trends in electronegativities

Leviafan [203]

Electronegativity of an element decreases as we move down a group on the periodic table and electronegativity increases while moving from left to right across a period on the periodic table.

Explanation:

The electronegativity increases as we move from left to right across a period because from left to right across a period, the nuclear charge is increasing Hence the attraction for the valence electrons also increases.
As we move down a group, the atoms of each element have an increasing number of energy levels. The distance between the nucleus and valence electron shell increases and reduces the attraction for valence electrons. Hence electronegativity decreases as we move from top to bottom down a group.

8 0

3 years ago