Why is chemistry a science but alchemy was not?

The standard emf for the cell using the overall cell reaction below is +2.20 V:

ANEK [815]

Answer:

emf generated by cell is 2.32 V

Explanation:

Oxidation: $2Al-6e^{-}\rightarrow 2Al^{3+}$

Reduction: $3I_{2}+6e^{-}\rightarrow 6I^{-}$

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Overall: $2Al+3I_{2}\rightarrow 2Al^{3+}+6I^{-}$

Nernst equation for this cell reaction at $25^{0}\textrm{C}$ -

$E_{cell}=E_{cell}^{0}-\frac{0.059}{n}log{[Al^{3+}]^{2}[I^{-}]^{6}}$

where n is number of electrons exchanged during cell reaction, $E_{cell}^{0}$ is standard cell emf , $E_{cell}$ is cell emf , $[Al^{3+}]$ is concentration of $Al^{3+}$ and $[Cl^{-}]$ is concentration of $Cl^{-}$

Plug in all the given values in the above equation -

$E_{cell}=2.20-\frac{0.059}{6}log[(4.5\times 10^{-3})^{2}\times (0.15)^{6}]V$

So, $E_{cell}=2.32V$

3 0

3 years ago

Question 1 of 15 2 Points What is another name for a pure substance? Answer here

maksim [4K]

Answer:

element

Explanation:

elements consist of pure substances

4 0

3 years ago

Tellurium is a period 5 chalcogen. Selenium is a period 4 chalcogen. If the only factor affecting ionization energies was the nu

notsponge [240]

Answer:

yes

Explanation: took quiz

4 0

3 years ago

HELP!!!!!!!!!!! *What are some of the safety concerns for Barium sulfate & Barium Sulfide? Explain

Alex

BaSO₄ is relatively harmless, but BaS is highly toxic.

BaSO₄ is quite insoluble (240 µg/100 mL). It is a mild irritant in cases of skin contact and inhalation. However, it is safe enough that health professionals ask patients to drink a suspension of BaSO₄. The Ba is opaque to X-rays, so it makes the stomach and intestines more visible to radiographers.

BaS is soluble (7.7 g/100 mL). It reacts slowly with water and more rapidly in the acid conditions of the stomach to release H₂S.

BaS + 2HCl ⟶ BaCl₂ + H₂S

An H₂S concentration of 60 mg/100 mL can be fatal within 30 min.

Don’t eat barium sulfide!

3 0

3 years ago

How do you unlock a post test on edmentum?

postnew [5]

Explanation:

A post-test or a mastery test can be unlocked if the learner who has the of it previously can complete the given tutorial with the test.

After the tutorial with the test, the learner will have to complete everything and if he passes the test with a completed answer then he will see that the Mastery Test has been unlocked. Also after the mastery test is unlocked it can be done again.

8 0

3 years ago