A student puts a glass of water in the freezer. Later, he notices ice forming on the surface of the water. Which property of water best explains why ice forms on its surface? A. It is made of polar molecules. B. It has low surface tension. C. It has weak adhesion. D. It is densest as a solid.

Answers

Answer 1

ℯ ℴ ℴ ℴℯℯ

it has a weak adhesion


Related Questions

An atom of 120In has a mass of 119.907890 amu. Calculate the mass defect (deficit) in amu/atom. Use the masses: mass of 1H atom

Answers

Answer:

a

Explanation:

answer is a on edg

If there are a 1000 ml per 1 L and a 1000g per kilogram
a. How many ml are there in 5.0 L?
b. How many kg are there in 230g?

Answers

Answer:

hbchbjH j jas a aa  a s ds d as das

Explanation:

Describe the similarities between H3O and NH3. Compare/contrast their shapes and polarities within the context of your answer. These molecules are called isoelectronic. Why

Answers

Answer:

Explanation:

[tex]H_3O^+[/tex] also known as hydronium ion is formed as a result of the reaction between an hydrogen proton and a water molecules.

i.e [tex]\mathtt{H^+ + H_2O \to H_3O^+}[/tex]

(molecular geometry for the hydronium ion shows that the lewis structure of hydronium ion possess a three hydrogen ion bonded to a central atom known as oxygen. The oxygen possess a lone pair with a positive ion. So we have three hydrogen atoms and a lone pair attached to the oxygen. We can now say that there are four groups as the steric number in which one of them is a lone pair. This give rise to the trigonal pyramidal shape of the [tex]H_3O^+[/tex] (hydronium ion) with a bond angle of about 109,5°

Similarly, [tex]NH_3[/tex] on the other hand also known as ammonia has a shape that can be also determined by the Lewis structure.

IN ammonia,  there are three hydrogen  and a lone pairs of electron spreading out as far away from each other  from the centre nitrogen. In essence, the valence shell electron pair around hydrogens tend to repel each other. Hence, giving it a trigonal pyramidal shape.

From above the similarities between H3O and NH3 is in their molecular geometry in which both  H3O and NH3 have the same shape.

These molecules are called isoelectronic. Why?

Isoelectronic molecules are molecules having the same number of electrons and same electronic configuration  structure. As a result H3O and NH3 possess the same  number of electrons in the same orbitals and they also posses the same structure.

Refer to the figure.
30. How many planes are shown in the figure?
31. How many planes contain points B, C, and E?
32. Name three collinear points.
3. Where could you add point G on plane N
so that A, B, and G would be collinear?
4. Name a point that is not coplanar with
A, B, and C.
5. Name four points that are coplanar.
BN

Answers

Answer:

  30. 5 planes are shown

  31. 1 plane

  32. CEF

  33. on line AB

  34. E or F

   35. ABCD or BCEF or CDEF or ACEF

Explanation:

30. Each of the surfaces of the rectangular pyramid is a plane. There are 5 planes.

__

31. 3 points define one plane only.

__

32. The only points shown on the same line segment are points E, F, and C.

__

33. If G is to be collinear with A and B, it must lie on line AB.

__

34. The only points shown that are not on plane N are points E and F. Either of those will do.

__

35. There are three planes that have 4 points shown on them. The four points that are on the same plane are any of ...

ABCDBCEFCDEF

Plane ACEF is not shown on the diagram, but we know that those 4 points are also coplanar. (Any point not on line CE, together with the three points on that line, will define a plane with 4 coplanar points.)

10. For the following isotopes that have missing information, fill in the missing informatic
complete the notation: 36P

Answers

Answer:

Krypton.

Explanation:

Krypton is an atom which has 36 protons in its nucleus. There are 31 isotopes of Krypton which have same number of protons i. e. 36, same number of electrons i. e. 36 but different number of neutrons. Isotope refers to those atoms having same atomic number i. e. number of proton but different mass number i. e. number of neutron. For example, in Krypton-78, there 36 protons and 42 neutrons.

In which of the following compounds does the carbonyl stretch in the IR spectrum occur at the lowest wavenumber?

a. Cyclohexanone
b. Ethyl Acetate
c. λ- butyrolactone
d. Pentanamide
e. Propanoyl Chloride

Answers

Answer:

a. Cyclohexanone

Explanation:

The principle of IR technique is based on the vibration of the bonds by using the energy that is in this region of the electromagnetic spectrum. For each bond, there is a specific energy that generates a specific vibration. In this case, you want to study the vibration that is given in the carbonyl group C=O. Which is located around 1700 cm-1.

Now, we must remember that the lower the wavenumber we will have less energy. So, what we should look for in these molecules, is a carbonyl group in which less energy is needed to vibrate since we look for the molecule with a smaller wavenumber.

If we look at the structure of all the molecules we will find that in the last three we have heteroatoms (atoms different to carbon I hydrogen) on the right side of the carbonyl group. These atoms allow the production of resonance structures which makes the molecule more stable. If the molecule is more stable we will need more energy to make it vibrate and therefore greater wavenumbers.

The molecule that fulfills this condition is the cyclohexanone.

See figure 1

I hope it helps!

When the equation MnO₄⁻ + I⁻ + H₂O → MnO₂ + IO₃⁻ is balanced in basic solution, what is the smallest whole-number coefficient for OH⁻?

Answers

Answer:

The smallest whole-number coefficient for OH⁻ is 2

Explanation:

Step 1: The equation redox reaction is divided into two half equations

Reduction half equation: MnO₄⁻  ----> MnO₂

Oxidation half-equation: I⁻  ---> IO₃⁻

Step 2: Next the atoms are balanced by adding OH⁻ ions and H₂O molecules to the appropriate side of each half equation;

MnO₄⁻ +  2H₂O ----> MnO₂ + 4OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O

Step 3 : The charges are then balanced by adding electrons to the appropriate sides of each half equation

MnO₄⁻ +  2H₂O + 3e⁻ ----> MnO₂ + 4OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O + 6e⁻

Step 4: Oxidation half equation is multiplied by 2 while reduction half equation is multiplied by 1 to balance the number of electrons gained and lost for the reaction

2MnO₄⁻ +  4H₂O + 6e⁻ ----> 2MnO₂ + 8OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O + 6e⁻

Step 5 : addition of the two half equations to yield a net ionic equation

2MnO₄⁻  + I⁻ + H₂O ----> 2MnO₂ + IO₃⁻ + 2OH⁻

The smallest whole number coefficient for OH⁻ is 2

A redox reaction is divided into two half equations which are shown below:

Reduction half equation: MnO₄⁻  ----> MnO₂

Oxidation half-equation: I⁻  ---> IO₃⁻

Atoms are balanced by adding OH⁻ ions and H₂O molecules to the appropriate side of each half equation to make the equation complete ;

MnO₄⁻ +  2H₂O ----> MnO₂ + 4OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O

The charges needs to be balanced and this is done by adding electrons to the appropriate sides of each half equation

MnO₄⁻ +  2H₂O + 3e⁻ ----> MnO₂ + 4OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O + 6e⁻

The equation needs to be balanced by multiplying the oxidation half equation by 2 while reduction half equation is multiplied by 1 to balance the number of electrons on both sides of the equations.

2MnO₄⁻ +  4H₂O + 6e⁻ ----> 2MnO₂ + 8OH⁻

I⁻ + 6OH⁻ ---> IO₃⁻ + 3H₂O + 6e⁻

The two half equations are then added and written together to form a net ionic equation

2MnO₄⁻  + I⁻ + H₂O ----> 2MnO₂ + IO₃⁻ + 2OH⁻

The smallest whole-number coefficient for OH⁻ is therefore 2.

Read more on https://brainly.com/question/17156617

If the rate of formation (also called rate of production) of compound C is 2M/s in the reaction A --->2C, what is the rate of consumption of A

Answers

Answer:

[tex]r_A=-1\frac{M}{s}[/tex]

Explanation:

Hello,

In this case, given the rate of production of C, we can compute the rate of consumption of A by using the rate relationships which include the stoichiometric coefficients at the denominators (-1 for A and 2 for C) as follows:

[tex]\frac{1}{-1} r_A=\frac{1}{2}r_C[/tex]

In such a way, solving the rate of consumption of A, we obtain:

[tex]r_A=-\frac{1}{2} r_C=-\frac{1}{2}*2\frac{M}{s}\\ \\r_A=-1\frac{M}{s}[/tex]

Clearly, such rate is negative which account for consumption process.

Regards.

Draw the product that valine forms when it reacts with excess CH3CH2OH and HCl followed by a wash with aqueous base.

Answers

Answer:

Product: ethyl L-valinate

Explanation:

If we want to understand what it is the molecule produced we have to analyze the reagents. We have valine an amino acid, in this kind of compounds we have an amine group ([tex]NH_2[/tex]) and a carboxylic acid group ([tex]COOH[/tex]).  Additionally, we have an alcohol ([tex]CH_3CH_2OH[/tex]) in the presence of HCl (a strong acid) in the first step, and a base ([tex]OH^-[/tex]).

When we have an acid and an alcohol in a vessel we will have an esterification reaction. In other words, an ester is produced. As the first step, the oxygen in the C=O (in the carboxylic acid group) would be protonated. In the second step, the ethanol attacks the carbon in the C=O of the carboxylic acid group producing a new bond between the oxygen in the ethanol and the carbon in the carboxylic acid. In step 3, a proton is transferred to produce a better leaving group ([tex]H_2O[/tex]). In step 4, a water molecule leaves the main structure to produce again the double bond C=O. Finally, a base ([tex]OH^-[/tex]) removes the hydrogen from the C=O bond to produce ethyl L-valinate

See figure 1

I hope it helps!

Which of the following is not the same as 1,400 mL? a. 1.4 cm³ b 1.4 L c. 1,400 cm³ d. 140 cL

Answers

answer should be 1.4 cm³

1 L = 10 and so

dL = 100 and then

cL = 1,000

mL = 0.001 m³

1 m³ = 1,000

dm³ = 1,000,000

cm³ = 1,000,000,000

mm³ = 1,000 L

So, 1 mL = 1 cm³ = 0.001 L = 0.1 cL

1,400 mL = 1,400 cm³ = 1.4 L = 140 cL

Answer:

1.4 cm^3

Explanation:

If one pound is the same as 454 grams, then convert the mass of 78 grams to pounds.

Answers

Answer:

0.17 lb

Explanation:

78 g * (1 lb/454 g)=0.17 lb

If you want additional help with chemistry or another subject for FREE, check out growthinyouth.org.

Does a reaction occur when aqueous solutions of potassium hydroxide and chromium(III) bromide are combined

Answers

Explanation:

Potassium hydroxide = KOH

Chromium(iii)bromide = CrBr3

Yes! A reaction occurs. This is given by the balanced equation;

3 KOH + CrBr3 → 3 KBr + Cr(OH)3

what is the valency of element sulphur ​

Answers

I am not to sure because I have not studied this

sorry not sure wish I can help u

Assume you dissolve 0.235 g of the weak benzoic acid, C6H5CO2H in enough water to make 100.0 mL of the solution and then titrate the solution with 0.108 M NaOH. Benzoic acid is a monoprotic acid.
1. What is the pH of the original benzoic acid solution before the titration is started?
2. What is the pH when 7.00 mL of the base is added? (Hint: This is in the buffer region.)
3. What is the pH at the equivalence point?

Answers

Answer:

1. pH = 2.98

2. pH = 4.02

3. pH = 8.12

Explanation:

1. Initial molarity of benzoic acid (Molar mass: 122.12g/mol; Ka = 6.14x10⁻⁵) is:

0.235 ₓ (1mol / 122.12g) = 1.92x10⁻³ moles / 0.100L = 0.01924M

The equilibrium of benzoic acid with water is:

C6H5CO2H(aq) + H2O(l) → C6H5O-(aq) + H3O+(aq)

And Ka is defined as the ratio between equilibrium concentrations of products over reactants, thus:

Ka = 6.14x10⁻⁵ = [C6H5O⁻] [H3O⁺] / [C6H5CO2H]

The benzoic acid will react with water until reach equilibrium. And equilibrium concentrations will be:

[C6H5CO2H] = 0.01924 - X

[C6H5O⁻] = X

[H3O⁺] = X

Replacing in Ka:

6.14x10⁻⁵ = [X] [X] / [0.01924 - X]

1.1815x10⁻⁶ - 6.14x10⁻⁵X = X²

1.1815x10⁻⁶ - 6.14x10⁻⁵X - X² = 0

Solving for X:

X = -0.0010→ False solution. There is no negative concentrations

X = 0.0010567M → Right solution.

pH = - log [H3O⁺] and as [H3O⁺] = X:

pH = - log [0.0010567M]

pH = 2.98

2.

pH of a buffer is determined using H-H equation (For benzoic acid:

pH = pka + log [C6H5O⁻] / [C6H5OH]

pKa = -log Ka = 4.21 and [] could be understood as moles of each chemical

The benzoic acid reacts with NaOH as follows:

C6H5OH + NaOH → C6H5O⁻ + Na⁺ + H₂O

That means NaOH added = Moles C6H5O⁻ And C6H5OH = Initial moles (1.92x10⁻³ moles - Moles NaOH added)

7.00mL of NaOH 0.108M are:

7x10⁻³L ₓ (0.108 mol / L) = 7.56x10⁻⁴ moles NaOH = Moles C₆H₅O⁻

And moles C6H5OH = 1.92x10⁻³ moles - 7.56x10⁻⁴ moles = 1.164x10⁻³ moles C₆H₅OH

Replacing in H-H equation:

pH = 4.21 + log [7.56x10⁻⁴ moles] / [ 1.164x10⁻³ moles]

pH = 4.02

3. At equivalence point, all C6H5OH reacts producing C6H5O⁻. The moles are 1.164x10⁻³ moles

Volume of NaOH to reach equivalence point:

1.164x10⁻³ moles ₓ (1L / 0.108mol) = 0.011L. As initial volume was 0.100L, In equivalence point volume is 0.111L and concentration of C₆H₅O⁻ is:

1.164x10⁻³ moles / 0.111L = 0.01049M

Equilibrium of  C₆H₅O⁻ with water is:

C₆H₅O⁻(aq) + H₂O(l) ⇄  C₆H₅OH(aq) + OH⁻(aq)

Kb = [C₆H₅OH] [OH⁻]/ [C₆H₅O⁻]

Kb = kw / Ka = 1x10⁻¹⁴ / 6.14x10⁻⁵ = 1.63x10⁻¹⁰

Equilibrium concentrations of the species are:

C₆H₅O⁻ = 0.01049M - X

C₆H₅OH = X

OH⁻ = X

Replacing in Kb expression:

1.63x10⁻¹⁰ = X² / 0.01049- X

1.71x10⁻¹² - 1.63x10⁻¹⁰X - X² = 0

Solving for X:

X = -1.3x10⁻⁶ → False solution

X = 1.3076x10⁻⁶ → Right solution

[OH⁻] =  1.3076x10⁻⁶

as pOH = -log [OH⁻]

pOH = 5.88

And pH = 14 - pOH

pH = 8.12

Write the IUPAC and common names, if any, of the carboxylate salts produced in the reaction of each of the following carboxylic acids with NaOH: 2-methylhexanoic acid
Part A
2-bromopropanoic acid Spell out the full name of the compound. If there is a common name separate your answers by a comma.
Part B
2-methylhexanoic acid Spell out the full name of the compound. If there is a common name separate your answers by a comma.

Answers

Answer:

Following are the explanation to this question:

Explanation:

The salts of carboxylate are named by the writing, which is also named as the creation of the first, which is followed by the name of the carboxylic acid were '-ic' of the acid end and replaced by the 'ate'.

Following are the description of the given reaction:

In reaction A:

2-Bromopropanoic acid= [tex]C_3H_5BrO_2[/tex]

[tex]C_3H_5BrO_2+NaOH[/tex]⇄ [tex]C_3H_4BrNaO_2 +H_2O[/tex]

The IUPAC name is Sodium-2-Bromopropanate

In reaction B:

2-Methylhexanoic acid= [tex]C_7H_{14}O_2[/tex]

[tex]C_7H_{14}O_2+NaOH[/tex]⇄ [tex]C_7H_{13}NaO_{2}+H_2O[/tex]

The IUPAC name is Sodium-2-Methyl hexanoate

The IUPAC name of compound  is Sodium-2-Bromopropanate in reaction 1 and in reaction 2 it is 2-Methylhexanoic acid.

The salts of carboxylate are named by the writing, which is also named as the creation of the first, which is followed by the name of the  compound carboxylic acid were '-ic' of the acid end and replaced by the 'ate'.

Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.

Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.

Thus, the IUPAC name of compound  is Sodium-2-Bromopropanate in reaction 1 and in reaction 2 it is 2-Methylhexanoic acid.

Learn more about compound,here:

https://brainly.com/question/14117795

#SPJ6

"Aqueous solutions of lead nitrate and ammonium chloride are mixed" together. Which statement is correct

Answers

Answer:

PbCl₂ will precipitate from solution.

Explanation:

Statements are:

Insufficient information is given.

Both NH4NO3 and PbCl2 precipitate from solution.

No precipitate forms.

PbCl2 will precipitate from solution.

NH4NO3 will precipitate from solution.

The reaction of ammonium chloride (NH₄Cl) with lead nitrate (Pb(NO₃)₂) is:

Pb(NO₃)₂ + 2NH₄Cl → PbCl₂ + 2 NH₄NO₃

Talking of rules of solubility, all nitrates are soluble in water, that means NH₄NO₃ is soluble and no precipitate is formed.

In the same way, all chlorides are soluble except silver chloride and lead chloride. That means:

PbCl₂ (Lead chloride) will precipitate from solution.

A small amount of solid calcium hydroxide is shaken vigorously in a test tube almost full of water until no further change occurs and most of the solid settles out. The resulting solution is:______.

Answers

Answer:

Lime water, [tex]Ca(OH)_{2}_({aq} )[/tex] is formed.

Explanation:

Lime-water is a clear and colourless dilute solution of aqueous calcium hydroxide salt.

Small amounts of calcium hydroxide salt,  [tex]Ca(OH)_{2}_(s)[/tex]  is sparsely soluble at room temperature when dispersed vigorously. if in excess, a white suspension called 'milk of lime'is formed.

I hope this explanation is helpful.

Pentanone was treated with excess sodium cyanide in HCl (aq) followed by hydrogen gas has over Pd. This produced:________
A. 2-amino-1-hexanol
B. 1-amino-2-methylpentan-2-ol
C. 1-cyano-1-pentanol
D. 2-aminomethylpentan-1-ol

Answers

Answer:

B. 1-amino-2-methylpentan-2-ol

Explanation:

In this case, the first step, we have the attack of the nucleophile cyanide ([tex] CN^-[/tex] produced by sodium cyanide to the carbon on the carbonyl group (C=O) producing a negative charge in the oxygen.

Then HCl protonates the molecule to produce a cyanohydrin. This cyanohydrin can be reduced by the action of hydrogen gas ([tex]H_2[/tex]) in the presence of a catalyst ([tex]Pd[/tex]), producing an amino group. With this in mind, the final molecule is: 1-amino-2-methylpentan-2-ol.

See figure 1 to further explanations

I hope it helps!

Select True or False: Pi bonds are covalent bonds in which the electron density is concentrated above and below a plane containing the nuclei of the bonding atoms and occurs by sideways overlap of p orbitals.

Answers

Answer:

True

Explanation:

In pi bonds, the electron density concentrates itself between the atoms of the compound but are present on either side of the line joining the atoms. Electron density is found above and below the plane of the line joining the internuclear axis of the two atoms involved in the bond.

Pi bonds usually occur by sideways overlap of atomic orbitals and this leads to both double and triple bonds.

A galvanic cell is powered by the following redox reaction:
2Zn2+(aq) + N2H4(aq) 4OH-zn2+ right arrow(aq) 2Zn(s) + N2(g) + 4H2O(I)
1. Write a balanced equation for the half-reaction that takes place at the cathode.
2. Write a balanced equation for the half-reaction that takes place at the anode.
3. Calculate the cell voltage under standard conditions.

Answers

if you could apply a picture with the question that would help.

Of the following substances, an aqueous solution of ________ will form basic solutions. NH4Br Pb(NO3)2 K2CO3 NaF

Answers

Answer:

K2CO3  and NaF

Explanation:

In order to ascertain which salt would form a basic solution we have to identify the classification of each of the salts.

- NH4Br: is the salt of a weak base (NH3) and a strong acid (HBr). This means that it would form an acidic solution.

- Pb(NO3): This is a normal salt, hence would not form a basic solution.

-  K2CO3: This is salt that forms a strongly alkaline/basic solution.

- NaF: it is the salt of a strong base, NaOH, and a weak acid, HF. This means this would form a basic solution.

The compounds capable to form basic solutions are[tex]\rm \bold {K_2CO_3 }[/tex] and NaF. Thus, options C and D are correct.

The basic solution has been given with the presence of a high number of hydroxide ions, while the acidic solution has been the presence of hydrogen ions.

The solution has been considered as basic when the compound has been constituted of a strong base. The constituents of the following compounds have been:

Ammonium bromide: The basic part is ammonia, and is a weak base. Thus, forms an acidic solution

Lead nitrate: The compound is salt and results in a neutral solution.

Potassium carbonate: The base has been carbonate, and a strong base. Thus forms the basic solution.

Sodium fluoride: The fluoride has been the basic part and has been a constituent of a strong base. It has been capable of forming a basic solution.

The compounds capable to form basic solutions are[tex]\rm \bold {K_2CO_3 }[/tex] and NaF. Thus, options C and D are correct.

For more information about the basic solution, refer to the link:

https://brainly.com/question/3595168

By heating a 93% pure kclo3 sample, what percentage of its mass is reduced?
2KCLO3---->2KCL+3O2​

Answers

Explanation:

free your mind drink water and go outside take fresh air you will get answers

Experiment:
Part I: Voltaic Cell
Assume that you are provided with the following materials:
Strips of metallic zinc, metallic copper, metallic iron
1M aqueous solutions of ZnSO4, CuSO4, FeSO4, and aqueous iodine (I2)
Other required materials to create Voltaic cells such as beakers, porous containers, graphite rods, a voltmeter, and a few wires with alligator clips.
In this modified version of the lab, after thoroughly studying the lab hand out and watching the videos, identify 4 different combinations of Voltaic cells that are possible to be created with the above materials.
For each cell created, include the following details.
Which electrode was the anode and which was the Cathode?
The anode and cathode half reactions.
Balanced equation for each cell you propose to construct.
Calculated Eocell
Short hand notation (line notation) for each cell (be sure to include the inactive electrode if needed)

Answers

Answer:

Here are four possible voltaic cells.  

Explanation:

1. Standard reduction potentials

                                         E°/V

I₂(s) + 2e⁻ ⟶ 2I⁻(aq);        0.54

Cu²⁺(aq) + 2e⁻ ⟶ Cu(s);   0.34

Fe²⁺(aq) + 2e⁻ ⟶ Fe(s);   -0.41

Zn²⁺(aq) + 2e⁻ ⟶ Zn(s);   -0.76

2. Possible Voltaic cells

(a) Zn/I₂

                                                                       E°/V

Anode:     Zn(s) ⟶ Zn²⁺(aq) + 2e⁻;                 0.76

Cathode:  I₂(s) + 2e⁻ ⟶ 2I⁻(aq);                     0.54

Cell:         Zn(s) +  I₂(s) ⟶  Zn²⁺(aq) + 2I⁻(aq); 1.30

Zn(s)|Zn²⁺(aq)∥I⁻(aq)|I₂(s)|C(s, graphite)

Zn is the anode; graphite is the cathode.

(b) Zn/Cu²⁺

                                                                          E°/V

Anode:     Zn(s) ⟶ Zn²⁺(aq) + 2e⁻;                    0.76

Cathode:  Cu²⁺(aq) + 2e⁻ ⟶ Cu(s);                  0.34

Cell:          Zn(s) +  Cu²⁺(s) ⟶  Zn²⁺(aq) + Cu(s); 1.10

Zn(s)|Zn²⁺(aq)∥Cu²⁺(aq)|Cu(s)

Zn is the anode; Cu is the cathode.

(c) Zn/Fe²⁺

                                                                            E°/V

Anode:     Zn(s) ⟶ Zn²⁺(aq) + 2e⁻;                     0.76

Cathode:  Fe²⁺(aq) + 2e⁻ ⟶ Fe(s);                    -0.41

Cell:          Zn(s) +  Fe²⁺(s) ⟶  Zn²⁺(aq) + Fe(s);  0.35

Zn(s)|Zn²⁺(aq)∥Fe²⁺(aq)|Fe(s)

Zn is the anode; Fe is the cathode.

(d) Fe/I₂

                                                                         E°/V

Anode:     Fe(s) ⟶ Fe²⁺(aq) + 2e⁻;                   0.41

Cathode: I₂(s) + 2e⁻ ⟶ 2I⁻(aq);                     0.54

Cell:         Zn(s) +  I₂(s) ⟶  Zn²⁺(aq) + 2I⁻(aq); 0.95

Fe(s)|Fe²⁺(aq)∥I⁻(aq)|I₂(s)|C(s, graphite)

Fe is the anode; graphite is the cathode.

 

A scientist observes that the electrical resistance of a superconducting material drops to zero when the material is cooled to very low temperatures. Which of the following statements best describes what the scientist is observing?
The scientist is observing the electrical power of a superconductor.
The scientist is observing the temperature of a superconductor.
The scientist is observing an intensive property of a superconductor.
The scientist is observing an extensive property of a superconductor

Answers

Answer:

The scientist is observing an intensive property of a superconductor.

Explanation:

An intensive property is a bulk property of matter. This means that an intensive property does not depend on the amount of substance present in the material under study. Typical examples of intensive properties include; conductivity, resistivity, density, hardness, etc.

An extensive property is a property that depends on the amount of substance present in a sample. Extensive properties depend on the quantity of matter present in the sample under study. Examples of extensive properties include, mass and volume.

Resistance of a superconducting material has nothing to do with the amount of the material present hence it is an intensive property of the superconductor.

Answer:

The scientist is observing an intensive property of a superconductor.

Explanation:

its the only one that makes logical sense

What is the pH of 10.0 mL solution of 0.75 M acetate after adding 5.0 mL of 0.10 M HCl (assume a Ka of acetic acid of 1.78x10-5)

Answers

Answer:

5.90

Explanation:

Initial moles of CH3COO- = 10.0/1000 x 0.75 = 0.0075 mol

Moles of HCl added = 5.0/1000 x 0.10 = 0.0005 mol

CH3COO- + HCl => CH3COOH + Cl-

Moles of CH3COO- left = 0.0075 - 0.0005 = 0.007 mol

Moles of CH3COOH formed = moles of HCl added = 0.0005 mol

pH = pKa + log([CH3COO-]/[CH3COOH])

= -log Ka + log(moles of CH3COO-/moles of CH3COOH)

= -log(1.78 x 10^(-5)) + log(0.007/0.0005)

= 5.90

Answer:

The correct answer is 5.895.

Explanation:

The reaction will be,

CHCOO⁻ + H+ ⇔ CH₃COOH

Both the HCl and the acetate are having one n factor.

The millimoles of CH₃COO⁻ is,

= Volume in ml × molarity = 10 × 0.75 = 7.5

The millimoles of HCl = Volume in ml × molarity = 5 × 0.1 = 0.5

Therefore, 0.5 will be the millimoles of CH₃COOH formed, now the millimoles of the CH₃COO⁻ left will be, 7.5-0.5 = 7.0

The volume of the solution is, 10+5 = 15 ml

The molarity of CH₃COO⁻ is, millimoles / volume in ml = 7/15

The molarity of CH₃COOH is 0.5/15

pH = pKa + log[CH₃COO⁻]/[CH₃COOH]

= 4.74957 + 1.146

= 5.895

In the laboratory, a general chemistry student measured the pH of a 0.425 M aqueous solution of benzoic acid, C6H5COOH to be 2.270.

Use the information she obtained to determine the Ka for this acid.

Ka(experiment) = _____

Answers

Answer:

Ka = 6.87x10⁻⁵

Explanation:

The equilibrium of benzoic acid in water is:

C₆H₅COOH(aq) + H₂O(l) ⇄ C₆H₅COO⁻(aq) + H₃O⁺(aq)

The equilibrium constant, Ka, is:

Ka = [C₆H₅COO⁻] [H₃O⁺] / [C₆H₅COOH]

The initial concentration of benzoic acid is 0.425M. In equilibrium its concentration is 0.425M - X and [C₆H₅COO⁻] [H₃O⁺] = X.

X is the reaction coordinate. How many acid produce C₆H₅COO⁻ and H₃O⁺ until reach equilibrium.

Concentrations in equilibrium are:

[C₆H₅COOH] = 0.425M - X[C₆H₅COO⁻] = X [H₃O⁺] = X

pH is defined as -log [H₃O⁺]. As pH = 2.270

2.270 = -log [H₃O⁺]

10^-2.270 = [H₃O⁺]

5.37x10⁻³M = [H₃O⁺] = X.

Replacing, concentrations in equilibrium are:

[C₆H₅COOH] = 0.425M - 5.37x10⁻³M = 0.4196M

[C₆H₅COO⁻] = 5.37x10⁻³M

[H₃O⁺] = 5.37x10⁻³M

Ka = [5.37x10⁻³M] [5.37x10⁻³M] / [0.4196M]

Ka = 6.87x10⁻⁵

Complete the sentences describing the cell.

a. In the nickel-aluminum galvanic cell, the cathode is ____ .
b. Therefore electrons flow from___ to ____.
c. The ____ electrode loses mass, while the ____ electrode gains mass.

Answers

Answer:

a. In the nickel-aluminum galvanic cell, the cathode is nickel electrode.

b. Therefore electrons flow from the aluminium electrode to the nickel electrode.

c. The aluminium electrode loses mass, while the nickel electrode electrode gains mass.

Explanation:

Voltaic or galvanic cells are electrochemical cells in which spontaneous oxidation-reduction reactions. The two halves of the redox reaction are separate and electron transfer is required to occur through an external circuit for the redox reaction to take place. That is, one of the metals in one of the half cells is oxidized while the metal of the other half cell is reduced, producing an exchange of electrons through an external circuit. This makes it possible to take advantage of the electric current.

Given:

E ⁰N i ⁺² = − 0.23 V   is the standard reduction potential for the nickel ion

E ⁰  A l ⁺³ =  − 1.66  V  is the standard reduction potential for the aluminum ion

The most negative potentials  correspond to more reducing substances. In this case, the aluminum ion is the reducing agent, where oxidation takes place. In the anodic half cell oxidations occur, while in the cathode half cell reductions occur. So the aluminum cell acts as the anode while the nickel cell acts as the cathode.

So a. In the nickel-aluminum galvanic cell, the cathode is nickel electrode.

The metal that is oxidized gives electrons to the metal that is reduced through the outer conductor. Then the electrons flow spontaneously from the anode to the cathode.

Then b. Therefore electrons flow from the aluminium electrode to the nickel electrode.

Ni⁺², being the cathode, accepts electrons, becoming Ni (s) and depositing on the Ni electrodes.

So, c. The aluminium electrode loses mass, while the nickel electrode electrode gains mass.

I think I'm typing it into my calculator wrong. I will give brainliest to whoever gets it right.

Answers

Answer:

36.7 mg

Explanation:

The following data were obtained from the question.

Original amount (A₀) = 65.1 mg

Rate constant (K) = 2.47×10¯² years¯¹

Time (t) = 23.2 years

Amount of substance remaining (A) =?

Thus, we can obtain the amount of substance remaining after 23.2 years as follow

ln A = lnA₀ – Kt

lnA = ln(65.1) – (2.47×10¯² × 23.2)

lnA = 4.1759 – 0.57304

lnA = 3.60286

Take the inverse of ln

A = e^3.60286

A = 36.7 mg

Therefore, the amount remaining after 23.2 years is 36.7 mg.

What is the primary source of energy in most living communities?

Answers

Answer:

The sun

Explanation:

The sun is the primary source of energy in most living communities. The producers or the green plants that prepare their own food by the use of sunlight and other natural resources. Carbon dioxide, water, and other minerals are used by the plants to make their food in the presence of chlorophyll. Plants are then consumed by the consumers. This chain helps in forming the food chain and the food web.

How did Jesseca Kusher create her new material?

Answers

Answer:

Jesseca Kusher, an 18-year-old researcher from Spartansburg, S.C., invented a paint-on coating for roofing shingles. Her formula could reduce a home's cooling costs and possibly cut ozone pollution in urban areas...

SUPPORT ME ...........

Answer:

Jesseca created mixtures containing graphite, gypsum, and mica that could be painted on roof shingles.

Explanation:

Hope this helped!!

Other Questions
a) Code a statement that creates an instance of an Account class using the default constructor and stores the object thats created in a variable named account.b) Code a statement that creates an instance of the Account class using a constructor that has two parameters named firstName and age, and store the object in a variable named account. Assume that variables with those names have already been declared and initialized so you can pass those variables to the constructor.c) Code a statement that sets the value of the Age property of an Account object named account to the value in a variable named newAge.d) Code a statement that will get the value of a public static field named Count thats defined in the Account class, and store the value in a new int variable named count. Assume that youve already created an object from this class thats named account. James Stillman is an investment adviser representative with Rock, Feller, and Standard (RFS), a covered adviser with its principal office in State O. Stillman works out of an office in State P and has 4 retail clients there. In addition, Stillman has 25 retail clients in State D, 6 retail clients in State M, and 1 retail client in State O. Stillman would be required to register as an investment adviser representative in A dentist uses a concave mirror (focal length 2 cm) to examine some teeth. If the distance from the object to the mirror is 1 cm, what is the magnification of the tooth Light with an intensity of 1 kW/m2 falls normally on a surface with an area of 1 cm2 and is completely absorbed. The force of the radiation on the surface is there 5 panakes in a stack.Elise make 40 pankcankes. How many stacks does Elise make? What else would need to be congruent to show that AABC = APQR by SSS?GiverAC =PRBC = QRA AC = PQB. AB = PQC. ZAZPD. ABBA In a buffer solution made of acetic acid and sodium acetate, if a small amount of acid is added, the added acid will react with whome? Calculate LaTeX: \DeltaG for a voltaic cell with Ecell = +0.24 V if the overall reaction involves a 3 electron reduction. Which of these are cultural projects? Select all that apply.restaurants and boutiques churches and train stationsgalleries and exhibitions museums and theaters AB and CD intersect at point O, ACO DBO, and BO CO . Prove that ACO DBO. Plz Help Me... Thanks The term Heart broken Angel refers to what? A cell biologist carefully measures the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G1 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA in one of the grasshopper daughter cells right after cytokinesis? What is active reading? (5 points)athinking about a story as you read itbwriting a story while you read anotherling a story to someone who is listeningkeeping your body moving while you read Hugh works in a Fish Packing Plant at Rocky Bay in British Columbia. He work 30 hours per week, 40 weeks a year, and earns $12.08 per hour. Find his weekly gross salary. Find his weekly net pay (deduct Federal, Provincial Income tax, CPP, EI Premiums).Calculate his yearly net pay and Calculate the percent of his gross income that is deducted each year. Write an equation showing the relationship between the lengths of the three sides of a right triangle. Two identical trucks have mass 5500 kg when empty, and the maximum permissible load for each is 8000 kg. The first truck, carrying a 3900 kg, is at rest. The second truck plows into it at 64 km/h, and the pair moves away at 44 km/h. As an expert witnes, you're asked to determine whether the second truck was overloaded. What do you report? Yes the truck is overloaded, or no, the truck is not overloaded? state any five literally device and give two examples each Rueben is in a biology class and the professor tells the students to find a lab partner. Rueben immediately approaches an Asian classmate because Rueben believes that all Asian students are naturally gifted in mathematics and science. Ruben's mental shortcut is an example of a(n) ________. round 1,965 to the nearest tenth Howcanwe minimizethe effect of disaster?