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aliya0001 [1]
3 years ago
6

How many seconds are required to produce 4.94 mg of chromium metal from an acidic solution of potassium dichromate, using a curr

ent of 0.234 a?
Chemistry
1 answer:
lyudmila [28]3 years ago
7 0
<span>Answer: The half-reaction is as followed: Cr2O72â’(aq) + 14H+ + 6e⒠→ 2Cr3+(aq) + 7H2O From the half-reaction, you can retrieve the following information: 1 mole of potassium dichromate =6 moles of e^- 6 moles of e^-=2 moles of Cr You will also need the following information: 1 mole of e^-=96,485 C and 1 mole of Cr=52.00g Calculate the number of moles that 4.94mg equates too: 4.94 mg=4.94 x 10^-3g of chromium*(1 mol/52.00g)=9.50 x 10^-5 mole of Cr How many moles of electrons are need to produce 9.50 x 10^-5 mole of Cr? Solve for moles of electrons: 9.50 x 10^-5 mole of Cr*(6 moles of e^-/2 mole of Cr)=2.85 x 10^-4 moles of e^- Whats the charge of 2.85 x 10^-4 moles of electrons? Use Faraday's constant: 2.85 x 10^-4 moles of e^-*(96,485 C/1 mole of e^-)=2.750 x 10^1 C Since current (A)=charge (C)/time (s), solve for time: A=C/s C/A=s 2.750 x 10^1 C/0.234 A=time (s) 1.18 x 10^2 s=118s=time <= 3 significant figures</span>
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Select the true statements regarding these resonance structures of formate.? Each carbon-oyxgen bond is somewhere between a sing
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Answer : Option 1) The true statement is each carbon-oxygen bond is somewhere between a single and double bond and the actual structure of format is an average of the two resonance forms.

Explanation : The actual structure of formate is found to be a resonance hybrid of the two resonating forms. The actual structure for formate do not switches back and forth between two resonance forms.

The O atom in the formate molecule with one bond and three lone pairs, in the resonance form left with reference to the attached image, gets changed into O atom with two bonds and two lone pairs.

Again, the O atom with two bonds and two lone pairs on the resonance form left, changed into O atom with one bond and three lone pairs. It concludes that each carbon-oxygen bond is neither a single bond nor a double bond; each carbon-oxygen bond is somewhere between a single and double bond.

Also, it is seen that each oxygen atom does not have neither a double bond nor a single bond 50% of the time.

7 0
3 years ago
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What is the VSEPR model of CB4I?
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Answer:

Molecular geometry Vsepr

According to VSEPR, the valence electron pairs surrounding an atom mutually repel each other; they adopt an arrangement that minimizes this repulsion, thus determining the molecular geometry. This means that the bonding (and non-bonding) electrons will repel each other as far away as geometrically possible.

Explanation:

3 0
3 years ago
In chemistry, what is the definition of the term salt? a compound consisting of an anion from an acid and a cation from a base a
inysia [295]
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3 years ago
The piece of iron that miguel measured had a mass of 51.1 g and a volume of 6.63 cm 3 . what did miguel calculate to be the dens
likoan [24]
Given:
Mass, m = 51.1 g
Volume, V = 6.63 cm³

By definition, 
Density = Mass/Volume
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In SI units,
Density = (7.7074 g/cm³)*(10⁻³ kg/g)*(10² cm/m)³
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Answer: 7.707 g/cm³ or 7707.4 kg/m³

4 0
3 years ago
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