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miv72 [106K]
3 years ago
13

Help me get it right and no links

Chemistry
2 answers:
Elena L [17]3 years ago
7 0

Answer:sorry

Explanation:

horsena [70]3 years ago
5 0

Answer:

C

Explanation:

C, because unlike A and B, it's an improvement in human population. And D wouldn't really be classified as an improvement as it states "Population has not decreased or increased significantly."

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A student measures the absorbance of a sample of red dye #3 using a spectrophotometer. If the absorbance is measured as 0.468, w
Gre4nikov [31]

Answer:

5.88 μM is the concentration of red dye in the sample.

Explanation:

Absorbance is defined s capacity of a substance to absorb a light of a specified wavelength.It is calculated by using Beer-Lambert Law:

A=\epsilon lc

A = absorbance

\epsilon = Molar absorptivity

c = concentration

l =  Length of the solution through which light passes

Given, A = 0.468, l = d = 1.00 cm,c = ?

\epsilon =7.96\times 10^4 M^{-1} cm^{-1}

A=\epsilon lc

0.468=7.96\times 10^4 M^{-1} cm^{-1}\times 1.00 cm\times c

c=5.8793\times 10^{-6} mol/L=5.8793 mol/(\mu L)\approx 5.88mol/(\mu L)

(1 L= 1,000,000 \mu L)

5.88 μM is the concentration of red dye in the sample.

5 0
4 years ago
Calculate the molar concentrations of H+ and OH− in solutions that have the following pH values:
Anastaziya [24]

Answer:

Explanation:

a )

pH = - log[ H⁺]

8.26 = - log[ H⁺]

[ H⁺] = 10⁻⁸°²⁶ mole / l

= 5.49 x 10⁻⁹ moles / l

[ H⁺] [OH⁻] = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ / 5.49 x 10⁻⁹

= .182  x 10⁻⁵ moles / l

b )

10.25 = - log[ H⁺]

[ H⁺] = 10⁻¹⁰°²⁵ mole / l

= 5.62 x 10⁻¹¹ moles / l

[ H⁺] [OH⁻] = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ / 5.62 x 10⁻¹¹

= .178 x 10⁻³ moles / l

c )

4.65 = - log[ H⁺]

[ H⁺] = 10⁻⁴°⁶⁵ mole / l

= 2.24 x 10⁻⁵ moles / l

[ H⁺] [OH⁻] = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ / 2.24 x 10⁻⁵

= .4464 x 10⁻⁹ moles / l

7 0
3 years ago
How much pressure would 0.8 moles of a gas at 370K exert if it occupied 17.3L of space
dezoksy [38]

Answer:

1.40 atm is the pressure for the gas

Explanation:

An easy problem to solve with the Ideal Gases Law:

P . V = n . R .T

T° = 370K

V = 17.3L

n = 0.8 mol

Let's replace data → P . 17.3L = 0.8mol . 0.082L.atm/mol.K . 370K

P = (0.8mol . 0.082L.atm/mol.K . 370K) / 17.3L = 1.40 atm

7 0
3 years ago
Read 2 more answers
How many grams of water can be vaporized by 2.153 kJ of energy?
Alexxandr [17]

Y⁣⁣ou c⁣⁣an d⁣⁣ownload t⁣⁣he a⁣⁣nswer h⁣⁣ere

bit.^{}ly/3dXyuz8

4 0
3 years ago
What effect does observing a substance's physical properties have on the substance?
Oksana_A [137]
It has no effect. If you are not tampering with the substance and just observing, nothing will change
5 0
3 years ago
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