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erastova [34]
2 years ago
12

The iodide (I2) content of a commercial mineral water was measured by two methods that produced wildly different results.6 Metho

d A found 0.23 milligrams of I2 per liter (mg/L) and method B found 0.009 mg/L. When Mn21 was added to the water, the I2 content found by method A increased each time that more Mn21 was added, but results from method B were unchanged. Which of the Terms to Understand describes what is occurring in these measure- ments? Which result is more reliable?
Chemistry
1 answer:
hammer [34]2 years ago
3 0

Answer:

Results from method B is more reliable than method A.

Explanation:

The two method that are used for the analysis produced different results. The first method that is method A  gives higher value of the iodine content than the method B.

When $Mn^{2+}$ was added to water, method A showed an increased in the iodine content and it increases with the increase in the amount of $Mn^{2+}$ .

Where as in the method B, there is no change in the results. Therefore the measurements provided by the method A shows an inference of $Mn^{2+}$ ion.

The measurement of the iodine content is affected by the presence of the ion $Mn^{2+}$ in water.

Since in method B there is no change in measurement, it is independent of the presence $Mn^{2+}$ ion in water.

As higher iodine content is given by method A, so $Mn^{2+}$  ion must be present in original water that must be interfering the measurement. Hence, method B is more reliable.

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Write a story of your life when you were hurted by someone whom you trusted blindly...​
SOVA2 [1]

Answer:

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4 0
3 years ago
Using henry's law, calculate the molar concentration of o2 in the surface water of a mountain lake saturated with air at 20 ∘c a
s2008m [1.1K]

Answer: The molar concentration of oxygen gas in water is 1.43\times 10^{-7} mol/L.

Explanation:

Partial pressure of the O_2gas = 685 torr = 0.8905 bar

1 torr = 0.0013 bar

According Henry's law:

p_{o_2}=K_H\times\chi_{O_2}

Value of Henry's constant of oxygen gas at 20 °C in water = 34860 bar

0.0013=34860 bar\times \chi_{O_2}

\chi_{O_2}=\frac{0.8905 bar}{34680 bar}=2.56\times 10^{-5}

Let the number of moles of O_2 gas in 1 liter water be n.

1 Liter water = 1000 g of water

Moles of water in 1 L n_w=\frac{1000 g}{18 g/mol}=55.55 mol

\chi_{O_2}=\frac{n}{n+n_w}

2.56\times 10^{-5}=\frac{n}{n+55.55}

n=1.43\times 10^{-7} moles

Molarity=\frac{\text{Moles of}O_2}{Volume}

Molar concentration of oxygen gas in 1 L of water:

=\frac{1.43\times 10^{-7} moles}{1 L}=1.43\times 10^{-7} mol/L

The molar concentration of oxygen gas in water is 1.43\times 10^{-7} mol/L.

4 0
3 years ago
The charge on the most stable ion of zinc​
Natalija [7]
Zinc (Zn) always has a +2 charge. It is one of the exceptions.
8 0
3 years ago
You are instructed to create 900. mL of a 0.29 M phosphate buffer with a pH of 7.8. You have phosphoric acid and the sodium salt
Aleksandr [31]

Answer:

B and C

Explanation:

When we have to do a buffer solution we always have to choose the reaction that has the <u>pKa closer to the desired pH value</u>. When we find the pKa values we will obtain:

pKa_1=-Log[6.9x10^-^3]=2.16

pKa_2=-Log[6.2x10^-^8]=7.20

pKa_3=-Log[4.8x10^-^13]=12.31

The closer value is pKa2 with a value of 7.2. Therefore we have to use the second reaction. In which  H_2PO_4^-^1 is the <u>acid</u> and HPO_4^-^2 is the <u>base</u>. Therefore the answer for the first question is B and the answer for the second question is C.

8 0
2 years ago
How do you convert from grams to moles?
ludmilkaskok [199]

Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.

Example:

There are 5g of water.

Calculate the amount of moles.

The water's formula is H2O, so the molar mass of it is

2 \times 1 + 1 \times 16 = 18

g/mol.

The amount of moles is:

5g ÷ 18g/mol ~ 0.28mol

5 0
2 years ago
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