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3 years ago

13

How many minutes would be required to electroplate 25.0 grams of chromium by passing a constant current of 4.80 amperes through

a solution containing CrCl3

1 answer:

True [87]3 years ago

5 0

Answer:

483.27 minutes

Explanation:

using second faradays law of electrolysis

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A metal pellet with a mass of 100.0 g, originally at 116°C, is dropped into a cup of water, initially at

Alina [70]

Answer:

C, 42g

Explanation:

In thermal equilibrium, both bodies (metal pellet and water) both have the same final temperature (46.3°C).

Assuming no heat is lost to surroundings,

the energy lost from metal pellet = energy gained for water

Since E = mc∆T

(energy = mass x specific heat capacity x temperature change)

mc∆T (metal pellet) = mc∆T (water)

100 x 0.568 x (116-46.3) = m 4.184 (46.3 - 23.8)

3958.96 = 94.14m

m = 42g

6 0

3 years ago

What is the % dissociation of a solution of acetic acid if at equilibrium the solution has a pH = 4.74 and a pKa = 4.74?

Ymorist [56]

Answer:

$\% diss = 50\%$

Explanation:

Hello there!

In this case, when considering weak acids which have an associated percent dissociation, we first need to set up the ionization reaction and the equilibrium expression:

$HA\rightleftharpoons H^++A^-\\\\Ka=\frac{[H^+][A^-]}{[HA]}$

Now, by introducing x as the reaction extent which also represents the concentration of both H+ and A-, we have:

$Ka=\frac{x^2}{[HA]_0-x} =10^{-4.74}=1.82x10^{-5}$

Thus, it is possible to find x given the pH as shown below:

$x=10^{-pH}=10^{-4.74}=1.82x10^{-5}M$

So that we can calculate the initial concentration of the acid:

$\frac{(1.82x10^{-5})^2}{[HA]_0-1.82x10^{-5}} =1.82x10^{-5}\\\\\frac{1.82x10^{-5}}{[HA]_0-1.82x10^{-5}} =1\\\\$

$[HA]_0=3.64x10^{-5}M$

Therefore, the percent dissociation turns out to be:

$\% diss=\frac{x}{[HA]_0}*100\% \\\\\% diss=\frac{1.82x10^{-5}M}{3.64x10^{-5}M}*100\% \\\\\% diss = 50\%$

Best regards!

6 0

3 years ago

Notice that "SO4" appears in two different places in this chemical equation. SO42− is a polyatomic ion called "sulfate." What nu

vichka [17]

Answer:

3.

Explanation:

Hello,

In this case, it is convenient to write the chemical reaction as:

$CaSO_4+AlCl_3\rightarrow CaCl_2+Al_2(SO_4)_3$

Which balanced turns out:

$3CaSO_4+2AlCl_3\rightarrow 3CaCl_2+Al_2(SO_4)_3$

Thus the number that should be in front of the calcium sulfate is 3 in order to balance the reaction.

Best regards.

8 0

3 years ago

PLEASE HELP!!!! <br><br> Draw a representation of John Dalton’s atomic model.

larisa [96]

Answer:

John Dalton's Atomic Model Below ⬇

Explanation:

7 0

2 years ago

Of the colors on the visible light spectrum, which one has the longest wavelength, lowest frequency, and lowest energy?

Elenna [48]

Answer:

Red

Explanation:

Violet - shortest wavelength, around 400-420 nanometers with highest frequency. They carry the most energy.

Indigo - 420 - 440 nm

Blue - 440 - 490 nm

Green - 490 - 570 nm

Yellow - 570 - 585 nm

Orange - 585 - 620 nm

Red - longest wavelength, at around 620 - 780 nanometers with lowest frequency and least amount of energy

Therefore, <em>red </em>is the answer you're looking for.

I hope this helps and that you have a great day! :)

5 0

3 years ago