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3 years ago

Can you help me on all of these question? (mostly on question number 4)

Chemistry

2 answers:

Alex787 [66]3 years ago

5 0

How bout a sifter..idk just guessing

abruzzese [7]3 years ago

3 0

On four, in real life, she could put it in a strainer and put a bowl below the strainer. The liquid will fall through and into the bowl, but the solids will stay in the strainer. That may not be correct in terms of your reading because I don't know what the reading is.

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The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichl

nevsk [136]

Complete Question

A student is extracting caffeine from water with dichloromethane. The K value is 4.6. If the student starts with a total of 40 mg of caffeine in 2 mL of water and extracts once with 6 mL of dichloromethane

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer:

The mass of caffeine extracted is $P = 39.8 \ mg$

Explanation:

From the question above we are told that

The K value is $K = 4.6$

The mass of the caffeine is $m = 40 mg$

The volume of water is $V = 2 mL$

The volume of caffeine is $v_c = 2 mL$

The number of times the extraction was done is n = 3

Generally the mass of caffeine that will be extracted is

$P = m * [\frac{V}{K * v_c + V} ]^3$

substituting values

$P = 40 * [\frac{2}{4.6 * 2 + 2} ]^3$

$P = 39.8 \ mg$

6 0

3 years ago

The kinetic molecular theory (KMT) deals specifically with

fgiga [73]

This kind of questions cannot be open because there might be many different answers depending of the focus.

In fact, I found the set of options that comes with this questions. This is:

A. behavior of ions.
B. molecular bonding.
C. molecular shape.
D. molecular motion.

Of course, the answer is the option D. molecular motion.

And, of course, you need an explanation.

It is good to know that the word kinetic refers to motion, so definetly kinetic molecular theory is a theory about the motion of the molecules.

With that you likely had been able to answer the question. But it is good to know what the molecular theory is.

The molecular kinetic molecular theory explains the properties and behavior of the gases in terms of the motion of its particles (molecules) making several assumptions about the energy, size and motion of such particles.

7 0

3 years ago

Read 2 more answers

The mole is defined as the amount of a substance containing the same number of particles as exactly 12 g of C-12. The amu is def

Pavlova-9 [17]

Answer:

Because it wouldn't make any sense

Explanation:

First of all, I think it's important to highlight the definition of isotope.

Isotope (Wikipedia): Variants of a particular chemical element <u>which differ in neutron number</u>...

This means that two isotopes are the same element but have different net mass per atom, due to the different number of neutrons.

Therefore, it's important to make the definition on the same isotope so that the proportion is equal. If the definition would be made on different isotopes, the proportion wouldn't have any sense. Let me be clear with this example:

mass in grams of a C-12 atom = 1.9944235 × 10 ^ -23 g --> this is the mass of a single C atom.

By definition --> 1 mol of anything = 6.02 x 10 ^ 23 particles of anything

Therefore, we know how much a single C atom weights. How many grams do you think that 6.02 x 10 ^ 23 atoms of C (i.e a mol of C) could weight??

1 single C atom ----------------------------- 1.9944235 × 10 ^ -23 g

6.02 x 10 ^ 23 atoms of C ------------ <u>12.006 g !!</u>

These 12 g is the same quantity than above! Therefore, 1 mol of C weights 12 g. If the definition were made with 13 g of C-13 (the other C isotope), these numbers will not be the same --> There would be a contradiction.

Regarding the second question, we need to search Ne-20 atomic mass in grams --> 3,3509177 × 10 ^ -23 g

Hence, if we follow the same rule, the amu would be 1/12 of Ne-20.

[ 3,3509177 × 10 ^ -23 g ] / 12 = 2.79 ^ -24 g

3 0

3 years ago

Calculate the mass of carbon dioxide produced from complete combustion of 16.6 g of octane, C8H18, in the following reaction. C8

Oksi-84 [34.3K]

Answer:

51.2g of CO2

Explanation:

The first step is to balance the reaction equation as shown in the solution attached. Without balancing the reaction equation, one can never obtain the correct answer! Then obtain the masses of octane reacted and carbon dioxide produced from the stoichiometric equation. After that, we now compare it with what is given as shown in the image attached.

7 0

3 years ago

Why neon is special from other chemical elements

kupik [55]

Noble gases react very unwillingly, because the outermost shell of electrons orbiting the nucleus is full, giving these gases no incentive to swap electrons with other elements. As a result, there are very few compounds made with noble gases. Like its noble gas comrades, neon is odorless and colorless.

6 0

2 years ago