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3 years ago

If the solvent front is 68 mm and the ring front of an unknown is 48mm from the original spot, what is the rf value?

Chemistry

1 answer:

Nat2105 [25]3 years ago

3 0

Given:

Distance of solvent front = 68 mm

Distance of unknown = 48 mm

To determine:

The rf value

Explanation:

The retention factor or the rf value is given by the ratio of distance traveled by the unknown to the distance traveled by the solvent front

RF = distance by unknown/distance by solvent

RF = 48/68 = 0.706

Ans: the RF value is 0.706

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The melting point of the metal potassium is 63.5c, while that of titanium is 1660c. what explanation can be given for this great

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3 years ago

Addition of an excess of lead (II) nitrate to a 50.0mL solution of magnesium chloride caused a formation of 7.35g of lead (II) c

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Answer:

[Cl⁻] = 0.016M

Explanation:

First of all, we determine the reaction:

Pb(NO₃)₂ (aq) + MgCl₂ (aq) → PbCl₂ (s) ↓ + Mg(NO₃)₂(aq)

This is a solubility equilibrium, where you have a precipitate formed, lead(II) chloride. This salt can be dissociated as:

PbCl₂(s) ⇄ Pb²⁺ (aq) + 2Cl⁻ (aq) Kps

Initial x

React s

Eq x - s s 2s

As this is an equilibrium, the Kps works as the constant (Solubility product):

Kps = s . (2s)²

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3 years ago

In the reaction Zn H 2SO 4→ ZNSO4 + H2, which, if any element is oxidized

Sedbober [7]

Answer:

I hope this answer is correct

Explanation:

This is an oxidation-reduction (redox) reaction:

Zn0 - 2 e- → ZnII (oxidation)

2 HI + 2 e- → 2 H0 (reduction)

Zn is a reducing agent, H2SO4 is an oxidizing agent.

Reactants:

Names: Zinc source: wikidata, accessed: 2019-09-07, Zinc powder (pyrophoric) source: ICSC, accessed: 2019-09-04, Zn source: wikidata, accessed: 2019-09-07

Appearance: Grey-to-blue powder source: ICSC, accessed: 2019-09-04

H2SO4 – Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02

Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07

Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02

Products:

ZnSO4 – Zinc sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04

Other names: White vitriol source: wikipedia, accessed: 2019-09-27, Goslarite source: wikipedia, accessed: 2019-09-27, Zinc sulfate (1:1) source: wikidata, accessed: 2019-09-02

Appearance: White powder source: wikipedia, accessed: 2019-09-27; Colourless hygroscopic crystals source: ICSC, accessed: 2019-09-04

Names: Dihydrogen source: wikidata, accessed: 2019-09-07, Hydrogen source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-07, H2 source: wikidata, accessed: 2019-09-07

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3 years ago