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ioda
3 years ago
12

HELP ME PLEASE NOWWWWWWW​

Chemistry
1 answer:
Zina [86]3 years ago
4 0

22 + 9 = 31

31 - 17.2 = 13.8

13.8 > 10 so student's guess is wrong

So the 3rd box.

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The diagram shows heat energy being transferred as hot water rises to the top of the pot and cool water sinks to the bottom.
Orlov [11]
I think it would be insulation
7 0
3 years ago
Which one of the samples contains the most molecules?
Alex

Answer: D is right

Explanation: One mole contains 6.0225 ·10^23 molecules

Despite of the substance

7 0
3 years ago
You wish to measure the iron content of the well water on the new property you are about to buy. You prepare a reference standar
djverab [1.8K]

1.04 ⨯ 10^{-4} M

<h3>Explanation</h3>

<em>A</em> = <em>ε</em> \cdot l \cdot c by the Beer-Lambert law, where

  • <em>A</em> the absorbance,
  • l the path length,
  • <em>ε</em> the molar absorptivity of the solute, and
  • c concentration of the solution.

<em>A</em> and <em>ε </em>are the same for both solutions. Therefore, l \cdot c is constant; l is inversely proportional to c. The 100 mL sample would have a concentration 1/4.78 times that of the 45.0 mL reference.

The 13.0 mL standard solution has a concentration of 5.17 ⨯ 10^{-4} M. Diluting it to 45.0 mL results in a concentration of 5.17 \times 10^{-4} \times \frac{13.0}{45.0} = 1.494 M.

c is inversely related to l for the two solutions. As a result, c₂ = c_1 \cdot \frac{l_1}{l_2} = 1.494 \times 10^{-4} \times \frac{1}{4.78} = 3.126 M.

The 30.0 mL sample has to be diluted by 30.0 / 100.0 times to produce the 100.0 mL solution being tested. The 100.0 mL solution has a concentration of 3.126 M. Therefore, the 30.0 mL solution has a concentration of 3.126 \times \frac{100.0}{30.0} = 1.04 ⨯ 10^{-4} M.

6 0
4 years ago
PLEASE HELPP ASAP!!!!!What is the equation for density A. D=M/V B. D=V/M C. D= M/V2 D. D=1/2 MV2
mestny [16]

The correct answer is option A.

D = M/V

The density of a substance is the ratio of its mass to its volume.

Density = mass / volume

or D = M/V

The unit of density is gram per milliliter or g/ml, when mass is expressed in gram or g and the volume is expressed in milliliter ml.

If we know the mass and volume of a substance we can calculate its density using the formula for density.


8 0
3 years ago
Calculate the number of molecules in 7 moles of oxygen
Alexxandr [17]

Answer:

4.21

Explanation:

use Avogadro's number

6.023 x 10^23

multiply this by 7 because you want to find 7 moles :

6.023 x 10^23 x 7 = 4.21

3 0
3 years ago
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