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mars1129 [50]
3 years ago
6

Please help 100 point s

Chemistry
2 answers:
ki77a [65]3 years ago
5 0
Where is the chart?????
Anni [7]3 years ago
5 0

air is NOT a compound - it is a mixture of different gases like O2, N2 n CO2. CO2 is a pure substance but NOT an element. so the CORRECT ans is


C) The chart shows the percentages of pure substances in a mixture.


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Please help me which one
mel-nik [20]
Non of the above because protons and neutrons don’t mix with each one there
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2 years ago
Blank is the total disappearance of all members of a species.
Vlad [161]

Answer:

Extinction

Explanation:

When a species becomes extinct, every last specimen has died out

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A 5.00-mL sample of blood was treated with trichloroacetic acid to precipitate proteins. After centrifugation, the resulting sol
Anarel [89]

Explanation:

According to the Beer-lambert' s law,

        Absrobance = absrobptitvity × lenght × concentration

So, if we will plot a graph between absrobance and concentration then we will obtain a straight line

Hence, formula to calculate slope of the graph is as follows.

   The slope of graph = \frac{\text{difference in absrobance at two points}}{\text{difference in concentrations at those points}}

The given data is as follows.

     A_{1} = 0.412 (first point)

     A_{2} = 0.642 (second point)

     C_{1} = 0.240 ppm (first point)

     C_{2} = 0.475 ppm (second point)

Hence, putting these values into the above formula we will calculate the value of slope as follows.

           Slope = \frac{\text{difference in absrobance at two points}}{\text{difference in concentrations at those points}}

                     = \frac{0.642 - 0.412}{0.475 - 0.240}

                      = \frac{0.23}{0.235}

                     = 0.978

It is known that for the graph, line equation can be written as follows.

                       y = mx + c  ........... (1)

where,      C = intercept

                 m = slope

Hence, calculate the value of intercept as follows.

           0.412 = 0.24 \times 0.978 + c

               c = 0.178

As it is given that the absorbance values 0.454 (the y-axis value). Therefore, putting this value into equation (1) we get the following.

                     y = mx + c

                  0.454 = x \times 0.978 + 0.178

                   0.276 = 0.978x

                         x = 0.282 ppm

Thus, we can conclude that the concentration of Pb in the given sample is 0.282 ppm.

3 0
3 years ago
Write the mechanism of the reaction of methyl benzoate to form methyl 2-nitrobenzoate.
Galina-37 [17]
The question is partially incorrect, because nitration of <span> methyl benzoate results in generation of methyl 3-nitrobenzoate, and not methyl 2-benzoate.

This a because of the present of ester group, which deactivated benzene ring at ortho and para position. Due to this, the electrophile (NO2+) attackes on meta position.

The detailed mechanism is attached below.</span>

8 0
3 years ago
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I need this very fast so please answer this first! I will mark you as the Brainiest and put my max points so please hurry!!!
Korolek [52]

Answer:

Answer C

Explanation:

Heat is used to turn the solid ice into liquid water

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