How many grams of Zn are in 0.356 mole of Zn?

The point in a titration at which the indicator changes is called the

irakobra [83]

Answer:

End point

Explanation:

The point at which the indicator changes color is called the endpoint. So the addition of an indicator to the analyte solution helps us to visually spot the equivalence point in an acid-base titration

#correct me if I'm wrong

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brainliest please thank you

8 0

2 years ago

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

#12 please! worth 40 points

Serga [27]

Okay so because of the difference in density a simple method for telling the difference between the two is to put a sample in a container with oil, because water has a higher density than the oil it would sink to the bottom but alcohol on the other hand is lighter than oil and would float on top of the oil.

However with this question I think that what you would do is use the ice to find out what the substance is, it would float on top of the liquid if it were water because the water is denser than ice but the ice would sink if it was alcohol because the alcohol is less dense than ice.

I hope this helps you, good luck : )

3 0

3 years ago

Name the following compounds:

timama [110]

A) sodium fluoride
B) rubidium oxide
C) boron trichloride
D) dihydrogen selenide
E) tetraphosphate hexoxide
F) iodine trichloride

6 0

3 years ago

Read 2 more answers

A 3.28 L solution is prepared by dissolving 535 g CaCl2 in water. The molar mass of CaCl2 is 110.98 g. What is the morality of t

andrey2020 [161]

Answer:

1.47 mol/L

Explanation:

Molarity is given as,

Molarity = Moles / Vol in L ------- (1)

Moles of CaCl₂,

Moles = Mass / M.Mass

Moles = 535 g / 110.98 g/mol

Moles = 4.82 mol

Now, putting values in eq. 1.

Molarity = 4.82 mol / 3.28 L

Molarity = 1.47 mol/L

5 0

2 years ago