Which term identifies the half-reaction that occurs at the anode of an operating electrochemical cell?

Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic

ale4655 [162]

A) 10.75 is the concentration of arsenic in the sample in parts per billion .

B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)It will take 1.37 years to remove all of the arsenic from the lake.

Explanation:

A) Mass of arsenic in lake water sample = 164.5 ng

The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.

To calculate the ppm of oxygen in sea water, we use the equation:

$\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9$

Both the masses are in grams.

We are given:

Mass of arsenic = 164.5 ng = $164.5\times 10^{-9} g$

$1 ng=10^{-9} g$

Volume of the sample = V = $15.3 cm^3$

Density of the lake water sample ,d= $1.00 g/cm^3$

Mass of sample = M = $d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g$

$ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75$

10.75 is the concentration of arsenic in the sample in parts per billion.

B)

Mass of arsenic in $1 cm^3$ of lake water = $\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g$

Mass of arsenic in $0.710 km^3$ lake water be m.

$1 km^3=10^{15} cm^3$

Mass of arsenic in $0.710\times 10^{15} cm^3$ lake water :

$m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g$

1 g = 0.001 kg

7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg

7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

$\frac{2.74}{41.90} days$

Then days required to remove 7,633.66 kg of arsenic from the lake water :

$=7,633.66\times \frac{2.74}{41.90} days=499.19 days$

1 year = 365 days

499.19 days = $\frac{499.19}{365} years = 1.367 years\approx 1.37 years$

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

$\frac{2.74}{41.90} days$

Then days required to remove 7,633.66 kg of arsenic from the lake water :

$=7,633.66\times \frac{2.74}{41.90} days=499.19 days$

1 year = 365 days

499.19 days = $\frac{499.19}{365} years = 1.367 years\approx 1.37 years$

It will take 1.37 years to remove all of the arsenic from the lake.

6 0

3 years ago

A column is packed with 0.5 g of a strongly acidic ion exchange resin in H+ form. A 1.0 M NaCl solution is passed through the co

Lena [83]

Answer:

The correct answer is 17 meq/g

Explanation:

Ion exchange capacity (IEC) express the total of active sites of a resin in which ions are attached because the greater molecular weight.

The exchange Reaction can be represented as

R-H $R-H^{+} + Na^{+} + Cl^{-} -> R-Na^{+} + HCl_{aq}$

The IEC value (in meq/g) is determinated by using the next equation:

IEC=[(mL of NaOH)*(M of NaOH)]/mass of resin

IEC [(17 mL)*(0.5 M)/0.5]= 17 meq/g

3 0

4 years ago

10 The graph below compares the density, in grams per cubic centimeter (g/cm'), of

ahrayia [7]

Answer: the awnser is A

Explanation:

Edge 2020

5 0

3 years ago

3. List the temperatures in order from warmest to

amid [387]

Answer:

3°F, 0°F, -11°F, -16°F, -20°F

Explanation:

The Fahrenheit scale is a temperature scale proposed in 1724 by the physicist Daniel Fahrenheit.

In this scale:

- The freezing point of water is set at 32 degrees

- The boiling point of water is set at 212 degrees

One degree in the Fahrenheit scale is indicated with the symbol $^{\circ}F$ .

The equivalence between temperature in Celsius degrees and Fahrenheit degrees is as follows:

$T(^{\circ}C)=\frac{5}{9}(T(^{\circ}F)-32)$ to convert from Fahrenheit to Celsius

$T(^{\circ}F)=\frac{9}{5}(T(^{\circ}C)+32)$ to convert from Celsius to Fahrenheit

The Fahrenheit scale is an increasing monotonic scale, it means that temperature goes from negative values towards positive values without interruption. Therefore, the temperatures listed from warmest to coldest are:

3°F, 0°F, -11°F, -16°F, -20°F

8 0

4 years ago

Mass = 35g Volume = 7cm3 What is the Density?

olga_2 [115]

Answer:

5 g/cm^3

Explanation:√3V=1.91293cm

7 0

3 years ago