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exis [7]
3 years ago
5

50 POINTS: PLEASE ANSWER AS QUICK AS POSSIBLE!

Chemistry
2 answers:
Dvinal [7]3 years ago
6 0

Explanation:

The lack of a control group

____ [38]3 years ago
5 0
The answer would be “the lack of a control group.” To make the results more accurate, the scientists should have used a placebo group to use as a comparison.
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Consider the chemical equation for the ionization of CH3NH2 in water. Estimate the percent ionization of CH3NH2 in a 0.050 M CH3
anyanavicka [17]

Answer:  The percent ionization of CH_3NH_2 in a 0.050 M CH_3NH_2(aq) solution is 8.9 %

Explanation:

CH_3NH_2+H_2O\rightarrow OH^-+CH_3NH_3^+

 cM                            0             0

c-c\alpha                       c\alpha            c\alpha

So dissociation constant will be:

K_b=\frac{(c\alpha)^{2}}{c-c\alpha}

Give c= concentration = 0.050 M and \alpha = degree of ionisation = ?

K_b=4.4\times 10^{-4}

Putting in the values we get:

4.4\times 10^{-4}=\frac{(0.050\times \alpha)^2}{(0.050-0.050\times \alpha)}

(\alpha)=0.089

percent ionisation =0.089\times 100=8.9\%

8 0
2 years ago
A chemistry student needs 30,0 mL of pentane for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the stu
Marta_Voda [28]

Answer:

1.878g

Explanation:

Volume = 30.0ml

Density = 0.626gcm−3

Mass = ?

Be careful in this kind of questions to check for the units. In this case one has to remember 1 mL equal 1 cm³ so density = 0.626g/ml

The relationship between all three parameters is given by the equationn below;

Mass = Density * Volume

Mass = 0.626g/ml * 30 = 1.878g

8 0
3 years ago
Which of these best describes the role of plants in the carbon-oxygen cycle? A. to absorb carbon dioxide from the atmosphere and
IceJOKER [234]

Answer:

A. to absorb carbon dioxide from the atmosphere and use it to make sugar

Explanation:

Green plants with the help of their green coloring pigment called chlorophyll helps to absorb sunlight. This sunlight helps in the process Called photosynthesis in which plants manufacture food (sugar) using CO2(Carbon dioxide)and Water to give Oxygen and Sugar. The oxygen is released back into the atmosphere.

6 0
3 years ago
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The Answer is 50. hope this helps
4 0
2 years ago
What do people mean when they say everything is connected
NARA [144]
A network.. where one thing ends another begins
3 0
3 years ago
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