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3 years ago

Energy pyramid worksheet

Chemistry

1 answer:

Taya2010 [7]3 years ago

6 0

Answer:

From top to bottom coyote, crow, squirrel, then acorn

Explanation:

The coyote has the least amount of energy and its the biggest predator so it belongs at the top. The crows eat squirrels and the squirrels eat acorns.

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Someone help please this is due today!!?

maria [59]

Answer:

I think beaker three will take longer to boil since there is more water present,compared to the other beakers

3 0

3 years ago

Dilution question In many of the experiments, you will be asked to prepare a standard solution by diluting a stock solution. You

riadik2000 [5.3K]

Answer:

We could do two 1:50 dilutions and one 1:4 dilutions.

Explanation:

Hi there!

A solution that is 1000 ug/ ml (or 1000 mg / l) is 1000 ppm.

Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.

Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.

We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):

First step (1:50 dilution):

Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).

Step 2 (1:50 dilution):

Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)

Step 3 (1:4 dilution):

Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.

6 0

3 years ago

How many grams of material is lost in the aqueous phase if two extractions are carried out on 100 mL of a 5% (m/v) aqueous solut

san4es73 [151]

Answer:

4.94g of material

Explanation:

Partition coefficient (Kp) of a substance is defined as the ratio between concentration of organic solution and aqueous solution, that is:

Kp = 8 = Concentration in Ethyl acetate / Concentration in water

100mL of a 5% solution contains 5g of material in 100mL of water. Thus:

8 = X / 100mL / (5g-X) / 100mL

Where X is the amount of material in grams that comes to the organic phase.

8 = X / 100mL / (5g-X) / 100mL

8 = 100X / (500-100X)

4000 - 800X = 100X

4000 = 900X

4.44g = X

Thus, in the first extraction you will lost 4.44g of material from the aqueous phase.

And will remain 5g-4.44g = 0.56g.

In the second extraction:

8 = X / 100mL / (0.56g-X) / 100mL

8 = 100X / (56-100X)

448 - 800X = 100X

448 = 900X

0.50g = X

In the second extraction, you will extract 0.50g of material

Thus, after the two extraction you will lost:

4.44g + 0.50g = 4.94g of material

6 0

3 years ago

Consider this reaction 2Mg(s)+O2(g) ———> 2MgO(s) What volume (in milliners) of gas is required to react with 4.03 g Mg at STP

nydimaria [60]

The volume of a gas that is required yo react with 4.03 g mg at STP is 1856 ml

calculation/

calculate the moles of Mg used

moles=mass/molar mass

moles of Mg is therefore=4.03 g/ 24.3 g/mol=0.1658 moles

by use of mole ratio of Mg:O2 from the equation which is 2:1

the moles 02=0.1679 x1/20.0829 moles

at STP 1 mole of a gas= 22.4 l

0.0895 moles=? L

by cross multiplication

=0.0895 moles x22.4 l/ 1 mole=1.8570 L

into Ml = 1.8570 x1000=1856 ml approximately to 1860

6 0

3 years ago

Among the following, which element has the lowest ionization energy?

d1i1m1o1n [39]

The answer is A. Na

because it's 5,1391

4 0

3 years ago