Whats the mass number of the atom when you add six protons and 6 electrons?

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

Water has a boiling point of 100.0°C and a Kb of 0.512°C/m. What is the boiling

Reil [10]

Answer:

The boiling point of a 8.5 m solution of Mg3(PO4)2 in water is 394.91 K.

Explanation:

The formula for molal boiling Point elevation is :

$\Delta T_{b} = iK_{b}m$

$\Delta T_{b}$ = elevation in boiling Point

$K_{b}$ = Boiling point constant( ebullioscopic constant)

m = molality of the solution

i = Van't Hoff Factor

Van't Hoff Factor = It takes into accounts,The abnormal values of Temperature change due to association and dissociation .

In solution Mg3(PO4)2 dissociates as follow :

$Mg_{3}(PO_{4})_{2}\rightarrow 3Mg^{2+} + 2 PO_{4}^{3-}$

Total ions after dissociation in solution :

= 3 ions of Mg + 2 ions of phosphate

Total ions = 5

i = Van't Hoff Factor = 5

m = 8.5 m

$K_{b}$ = 0.512 °C/m

Insert the values and calculate temperature change:

$\Delta T_{b} = iK_{b}m$

$\Delta T_{b} = 5\times 0.512\times 8.5$

$\Delta T_{b} = 21.76 K$

Boiling point of pure water = 100°C = 273.15 +100 = 373.15 K

$\Delta T_{b} = T_{b} - T_{b}_{pure}$

$T_{b}_{pure}$ = 373.15 K[/tex]

21.76 = T - 373.15

T = 373.15 + 21.76

T =394.91 K

8 0

3 years ago

What tittle might the indigenous communities of the Americans give the age of exploration

Rom4ik [11]

Answer:

Poop

Explanation:everyone like poop

4 0

3 years ago

Calculate the number of moles of a gas that is present in a 7.55 L container at 45°C, if the gas exerts a pressure of 725mm Hg.

vovikov84 [41]

Answer: The number of moles of gas present is 0.276 moles

Explanation:

To calculate the number of moles of gas, we use the equation given by ideal gas:

PV = nRT

where,

P = Pressure of the gas = 725 mm Hg

V = Volume of the gas = 7.55 L

n = number of moles of gas = ?

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of the gas = $45^oC=(45+273)K=318K$

Putting values in above equation, we get:

$725mmHg\times 7.55L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 318K\\\\n=0.276mol$

Hence, the number of moles of gas present is 0.276 moles

4 0

3 years ago

Help me with this please

myrzilka [38]

Explanation:

I can't guess it properly

8 0

3 years ago