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Leviafan [203]
2 years ago
15

1 Ca (s) + 2 HF (aq) → 1 CaF2 (s) +1 H2 (g) Identify the coefficient(s). Identify the subscript(s). What is the state of each of

the reactants? What will serve as evidence that a reaction has occurred?
Chemistry
1 answer:
blagie [28]2 years ago
6 0

Answer :

The coefficients are, 1 in Ca, 2 in HF, 1 in CaF₂ and 1 in H₂

The subscripts are, 2 in CaF₂ and 2 in H₂

The states of reactants are, Ca in solid state (s) and HF in aqueous state (aq).

The evidence that a reaction occurred is, the new substances are formed in the chemical reaction.

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.

If the amount of atoms of each type on the left and right sides of a reaction differs then to balance the equation by adding coefficient in the front of the elements or molecule or compound in the chemical equation.

The coefficient tell us about that how many molecules or atoms present in the chemical equation.

Coefficient : It is a number that written in front of the element, molecule or ion.

Subscript : It is a small number that placed slightly lower-right than the normal text.

The given balanced chemical reaction is:

1Ca(s)+2HF(aq)\rightarrow 1CaF_2(s)+1H_2(g)

In this reaction:

The coefficients are, 1 in Ca, 2 in HF, 1 in CaF₂ and 1 in H₂

The subscripts are, 2 in CaF₂ and 2 in H₂

The states of reactants are, Ca in solid state (s) and HF in aqueous state (aq).

The evidence that a reaction occurred is, the new substances are formed in the chemical reaction.

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Zepler [3.9K]

1) Consider the following silica gel TLC plate of compounds A, B, and C developed in hexanes:

<span><span>Determine the Rf values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent.</span>Which compound, A, B, or C, is the most polar?<span>What would you expect to happen to the Rf values if you used acetone instead of hexanes as the eluting solvent?</span><span>How would the Rf values change if eluted with hexanes using an alumina TLC plate?</span></span>

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2) You are trying to determine a TLC solvent system which will separate the compounds X, Y, and Z. You ran the compounds on a TLC plate using hexanes/ethyl acetate 95:5 as the eluting solvent and obtained the chromatogram below. How could you change the solvent system to give better separation of these three compounds?

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3) After a rather lengthy organic chemistry synthesis procedure, a student ran the product of the reaction on a TLC plate and obtained the result below. What might he/she have done wrong, if anything?

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4) A student spots an unknown sample on a TLC plate. After developing in hexanes/ethyl acetate 50:50, he/she saw a single spot with an Rf of 0.55. Does this indicate that the unknown material is a pure compound? What can be done to verify the purity of the sample?

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6) Plate A, below, represents the TLC chromatogram of a compound run in hexanes. The same compound was then spotted on a large TLC plate and again run in hexanes. Which TLC plate, B, C, or D, correctly represents how far the compound would run on the longer plate?

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Back to TLC

Original content © University of Colorado at Boulder, Department of Chemistry and Biochemistry.
The information on these pages is available for academic use without restriction.
3 0
1 year ago
In the activity, click on the E∘cell and Keq quantities to observe how they are related. Use this relation to calculate Keq for
joja [24]

Answer:

ΔG° = -118x10³ J/mol

Explanation:

The two half-reactions in the cell are:

Oxidation half-reaction:

Co(s) → Co²⁺(aq) + 2e⁻; E° = -0,28V

Reduction half-reaction:

Cu²⁺(aq)+2e⁻ → Cu(s); E° = 0,34V

The E° of the cell is defined as:

E_{cell} = E_{red} - E_{ox}

Replacing:

0,34V - (-0,28V) = 0,62V

It is possible to obtain the keq from E°cell with Nernst equation thus:

nE°cell/0,0592 = log (keq)

Where:

E°cell is standard electrode potential (0.62 V)

n is number of electrons transferred (2 electrons, from the half-reactions)

Replacing:

0,62V×2/0,0592 = log (keq)

20,946 = log keq

keq = 8,83x10²⁰≈ 5,88x10²⁰

ΔG° is defined as:

ΔG° = -RT ln Keq

Where R is gas constant (8,314472 J/molK) and T is temperature (298K):

ΔG° = -8,314472 J/molK×298K ln5,88x10²⁰

<em>ΔG° = -118x10³ J/mol</em>

<em />

I hope it helps!

8 0
2 years ago
Methane (CH4) reacts with excess oxygen gas (O2) to produce carbon dioxide (CO2) and water (H2O). What is the percent yield of c
musickatia [10]
(29.8 g) / [0.184 mol (44.00964 g CO2/mol)] =0.832= 83.2% yield CO2

(hope this helps)
4 0
1 year ago
Read 2 more answers
A new student is planning to use thin layer chromatography (TLC) for his research project. After setting up the apparatus the st
tamaranim1 [39]

Answer:

The open system evaporates the solvent in the solution

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During TLC, the sample is dotted on the plate and inserted into a suitable solvent. The solvent moves up the plate and achieves the required separation of the mixture.

Most of these solvents used used TLC are volatile organic compounds. Therefore, if the TLC set up is left open, the solvent will evaporate leading to poor results after running the TLC experiment.

7 0
2 years ago
Identify the precipitate (if any) that forms when nach3coo (also written as nac2h3o2) and hcl are mixed. express your answer as
Karolina [17]
When NaCH3Coo mixed with HCl we will get NaCl and CH3CooH as shown in the following balanced equation:

NaCH3Coo + HCl → NaCl + CH3CooH
so from this equation, we can conclude that is no precipitate because all we get is the acetic acid which found in vinegar and the NaCl which is very soluble so we don't have any precipitate.
so, your answer is no precipitate, no reaction
3 0
1 year ago
Read 2 more answers
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