1. What was the purpose of creating a sodium bicarbonate solution? What was the purpose of adding soap to the solution?

Answer:

Here's what I find  

Explanation:

Sodium vapour produces mostly yellow light.

Mercury vapour produces mostly blue light.

A white car reflects all colours back to our eyes.

A coloured car, say green, absorbs all the other colours and reflects the green.

Under a sodium light, a white or a yellow car will appear yellow. A red car will be nearly black because there is no red light to reflect.

Under a mercury light, a white or a blue car will appear blue. A yellow car will be quite dark, but there will be a yellowish tinge because there is some yellow in the Hg spectrum for it to reflect.  

The picture below shows a red car and a black car under sodium light. Can you tell which is which?

Answer:

E) n=4 l=2 ml=1 ms= 1/2

Explanation:

Arsenic is a member of group 15 in the periodic table. Its electronic configuration is;

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3. Its condensed electronic configuration can be written as [Ar]4s2 3d10 4p3. This electronic configuration shown here can now enable us to consider each option given in the question in order to meaningfully arrive at a logical answer.

If we look at option E, the data given for that electron is; n=4 l=2 ml=1 ms= 1/2. This refers to an electron in a 4d orbital. In the ground state configuration of arsenic shown above, there is no 4d orbital, hence option E must be the correct answer.

Answer: Thus 234 kJ of energy are required to produce 1.00 kilogram of iron metal

Explanation:

To calculate the number of moles , we use the equation:

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]  

Putting values , we get:

[tex]\text{Moles of iron}=\frac{1000g}{56g/mol}=17.8moles[/tex]    (1.00kg=1000g)

The balanced chemical reaction is:

[tex]Fe_2O_3(s)+2CO(g)\rightarrow 2Fe(s)+3CO_2(g)[/tex]   [tex]\Delta H=+26.3kJ[/tex]

Given :

Energy released when 2 moles of [tex]Fe[/tex] is produced = 26.3 kJ

Thus Energy released when 17.8 moles of [tex]Fe[/tex] is produced =

= [tex]\frac{26.3kJ}{2}\times 17.8=234kJ[/tex]

Thus 234 kJ of energy are required to produce 1.00 kilogram of iron metal

Answer:

See the explanation

Explanation:

Our reactions for this question are:

a) Cr+3(aq) + 3e- → Cr(s) ________

b) Ag(s) → 1e- + Ag+1(ag) ________

c) Mn(s) → 5e- + Mn+5(aq) ________

d) Sn+2(aq) + 2e- → Sn(s) ________

Now, we have to remember the definition of oxidation and reduction. In a reduction reaction,  the substance will gain electrons, in other words: "The electrons would be placed on the left side, in the side of the reagents. In an oxidation reaction, the substance will lose electrons, in other words: "The electrons would be placed on the right side, in the side of the products".

With this in mind we will have:

a) Cr+3(aq) + 3e- → Cr (s)(Reduction)

b) Ag(s) → 1e- + Ag+1(ag) (Oxidation)

c) Mn(s) → 5e- + Mn+5(aq) (Oxidation)

d) Sn+2(aq) + 2e- → Sn(s) (Reduction)

I hope it helps!

Answer:

The BaSO₄ precipitates as a solid.

Explanation:

In order to determine the precipitation, we need to look at the reactants, we have: Ba(NO₃)₂ and Li₂SO₄

Salts from nitrate are all soluble and sulfates can make precipitate if they react to elements from group 2. (Solubility rules) So this reaction, has a precipitate but we can predict it, if we look at the reaction and we take acount the Kps:

Ba(NO₃)₂ (aq) + Li₂SO₄ (aq)  →  2LiNO₃ (aq)  +  BaSO₄ (s) ↓

Let's find out the moles of each ion:

Ba(NO₃)₂ (aq) →  Ba²⁺  (aq)  +  2NO₃⁻  (aq)

0.8 L . 0.0002 M = 1.6×10⁻⁴ moles. These are the moles of Ba²⁺ in 1 L of solution, so [Ba²⁺] = 1.6×10⁻⁴ M

Li₂SO₄ (aq) →  2Li⁺ (aq)  +  SO₄⁻² (aq)

0.2 L . 0.0005 M = 1×10⁻⁴ M. These are the moles of sulfate, in 1 L of solution so [SO₄⁻²] =  1×10⁻⁴ M

BaSO₄ (s)  ⇆   Ba²⁺  (aq) + SO₄⁻² (aq)      Kps = 1.08×10⁻¹⁰

We need to compare Kps to [ Ba²⁺] . [SO₄⁻²]

[ Ba²⁺] . [SO₄⁻²] = 1.6 ×10⁻⁸ >  Kps →  Precipitate.

If  [Ba²⁺] . [SO₄⁻²] = Kps  → Solution is saturated

If [ Ba²⁺] . [SO₄⁻²] < Kps → There is no precipitate formed, or if it is formed, it will be quickly dissolved to reach saturation.

Answer:

Oxygen is more electronegative than carbon.

Explanation:

Electronegativity increases from left to right across the periodic table. Since oxygen is further right than carbon, it is more electronegative. Also, if you look at a chart of electronegativity, oxygen has an electronegativity of 3.44 while carbon has an electronegativity of 2.55.

So oxygen is more electronegative than carbon. Hope this helps.

The sand that grained will be quickly chemically weathered away should be option b. ferromagnesian silicate minerals.

It should be considered as the Silicate minerals where cations of iron and the form of magnesium should be important for the chemical components. It is used for covering up the minerals. Also, calcite should be normal weather via the solution process so it required a lot of water that contains a high amount of carbonic acid.

Hence, the correct option is b.

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Answer:

Ge: [Ar] 3d10 4s2 4p2 => 6 electrons in the outer shell

Br: [Ar] 3d10 4s2 4p5 => 7 electrons in the outer shell

Kr: [Ar] 3d10 4s2 4p6 => 8 electrons in the outer shell

Explanation:

The electron affinity or propension to attract electrons is given by the electronic configuration. Remember that the most stable configuration is that were the last shell is full, i.e. it has 8 electrons.

The closer an atom is to reach the 8 electrons in the outer shell the bigger the electron affinity.

Of the three elements, Br needs only 1 electron to have 8 electrons in the outer shell, so it has the biggest electron affinity (the least negative).

Ge: needs 2 electrons to have 8 electrons in the outer shell, so it has a smaller (more negative) electron affinity than Br.

Kr, which is a noble gas, has 8 electrons and is not willing to attract more electrons at all, the it has the lowest (more negative) electron affinity of all three to the extension that really the ion is so unstable that it does not make sense to talk about a number for the electron affinity of this atom.

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Answer:

e) 4-bromo-3,8-dimethylbicyclo[5.2.0]nonane

Explanation:

The missing image of the the  compound we are to name is attached below.

Before we can name an organic compound; It is crucial we know the guiding rules in naming them.

1. Select the longest continuous carbon chain as the root hydrocarbon and name according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group.

2. Number the carbon atoms in the root hydrocarbon from the end which gives the lowest number to the substituents.

3. If the same substituent is present two  or more times  in a molecule; the number of this substituent is indicated by the prefix di -(2), tri - (3) , tetra - (4) etc attached to the substituent name.

4. If there is more than one type of substituent in the molecule ; the substituents are named according to the alphabetical order but where  there are mixed substituents ; the inorganic are named first.

5. In selecting and numbering the longest continuous chain, the functional groups are given preference over substituents., i.e the functional group is given the smallest possible number.

In the light of the above guiding rules; we were able to name the given compound because the compound contains nine carbons in the ring form which result to root name nonane. The two methyl are on the third and eight carbon; bromine is on the fourth carbon ; there are two cyclic ring present in the compound where we have 5 carbons in one structure, another 2 carbons in the second structure and zero carbon in the bridge structure which eventually result to the correct  name:

4-bromo-3,8-dimethylbicyclo[5.2.0]nonane

-lg[H+]=1.5

which means that [H+]=0.03M

pOH=14-pH=14-1.5=12.5

-lg[H+]=1.5

which means that [H+]=0.03M

pOH=14-pH=14-1.5=12.5

the hydroxide ion concentration. is 12.5.

The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH) Example: What is the hydronium ion concentration in a solution that has a pH of 8.34? On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34).

For a 0.025 M HCl solution the concentration of the hydrogen ions, [H+] , is 0.025 moles/liter (i.e. 0.025 M). pH is defined as −log[H+] . Substituting 0.025 into the equation for pH we find that the 0.025 M HCl solution has a pH of -log(0.025) = 1.60.

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Answer:

The concentration of the borax solution is 0.1066 M

Explanation:

Step 1: Dtaa given

Volume of a sample of aqueous borax solution = 20.00 mL = 0.020 L

Molarity of H2SO4  = 1.03 M

Volume of the H2SO4 = 2.07 mL = 0.00207 L

Step 2: The balanced equation

Na2B4O7*10H2O(borax) + H2SO4 ⇆ Na2SO4 + 4 H3BO3 + 5 H2O

Step 3: Calculate molarity of borax solution

b*Ca*Va = a * Cb*Vb

⇒with B = the coefficient of H2SO4 = 1

⇒with Ca = the concentration of borax = TO BE DETERMINED

⇒with Va = the volume of borax = 0.020 L

⇒with a = the coefficient of borax = 1

⇒with Cb = the concentration of H2SO4 = 1.03 M

⇒with Vb = the volume of H2SO4 = 0.00207 L

Ca*0.020 L = 1.03 M * 0.00207 L

Ca = (1.03 * 0.00207) / 0.020

Ca = 0.1066 M

The concentration of the borax solution is 0.1066 M

Answer:

A.Electrolysis

Explanation:

A.Electrolysis

For example,  electrolysis of solution of NaCl in water gives H2 and O2.

Answer:

Volume of NaOH, aka V2 = 6.32 mL to 3 sig. fig.

A chemistry student weighs out 0.0941 g of hypochlorous acid (HClo) into a 250. ml. volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.2000 M NaOH solution. Calculate the volume of NaOH solution the student will need to add to reach the equivalence point. Round your answer to 3 significant digits mL.

Explanation:

1 mole HClO = 74.44g

0.0941g = [tex]\frac{0.0941}{74.44}[/tex] = 0.00126 moles

Concentration = no. of moles/volume in L

Hence, Concentration of HClO = 0.00126/ 0.250L

= 0.005M.

C1V1 =C2V2

0.005 × 250 mL = 0.2 × V2

Volume of NaOH, aka V2 = 6.32 mL to 3 sig. fig.

Answer:

Heat is thermal energy that flows, and thermal energy is the part of internal energy that can be transferred

Explanation:

Answer:

If 51.8 of Pb is reacting, it will require 4.00 g of O2

If 51.8 g of PbO is formed, it will require 3.47 g of O2.

Explanation:

Equation of the reaction:

2 Pb + O2 → 2 PbO

From the equation of reaction, 2 moles of lead metal, Pb, reacts with 1 mole of oxygen gas, O2, to produce 2 moles of lead (ii) oxide, PbO

Molar mass of Pb = 207 g

Molar mass of O2 = 32 g

Molar mass of PbO = 207 + 32 = 239 g

Therefore 2 × 207 g of Pb reacts with 32 g of O2 to produce 2 × 239 g of PbO

= 414 g of Pb reacts with 32 g of O2 to produce 478 g of PbO

Therefore, formation of 51.8 g of PbO will require (32/478) × 51.8 of O2 = 3.47 g of O2.

If 51.8 of Pb is reacting, it will require (32/414) × 51.8 g of O2 = 4.00 g of O2

Answer:

[tex]Fe_2O_3+3CO\Rightarrow \:2Fe+3CO_2[/tex]

Explanation:

[tex]Fe_2O_3+CO\Rightarrow \:2Fe+CO_2\\\\Fe_2O_3+3CO\Rightarrow \:2Fe+3CO_2[/tex]

Best Regards!

Answer:

[tex]m_{solution}=470g[/tex]

Explanation:

Hello,

In this case, a solution is formed when a solute is completely dissolved in a solvent, thus, for this situation, the sugar is the solute and the water the solvent but in addition to them we find spices which are also considered in the total mass of the solution. In such a way, for computing the total mass we must add the mass of three constituents (115 g sugar, 350 g water and 5 g spices) as shown below:

[tex]m_{solution}=115g+350g+5g\\\\m_{solution}=470g[/tex]

Best regards.

Answer:

Explanation:

the forces between the molecules are stronger in solid than in liquids

Answer:

calcium chloride dihydrate

Answer:

H⁺(aq) + H₂O(l) ⇄ H₃O⁺(aq)

Explanation:

According to Brönsted-Lowry acid-base theory, an acid is a substance that donates H⁺. Let's consider the molecular equation showing that benzoic acid is a Brönsted-Lowry acid.

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

The complete ionic equation includes all the ions and molecular species.

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

The net ionic equation includes only the ions that participate in the reaction and the molecular species.

H⁺(aq) + H₂O(l) ⇄ H₃O⁺(aq)

Explanation:

It is given that,

The electron in a hydrogen atom, originally in level n = 8, undergoes a transition to a lower level by emitting a photon of wavelength 3745 nm. It means that,

[tex]n_i=8[/tex]

[tex]\lambda=3745\ nm[/tex]

The amount of energy change during the transition is given by :

[tex]\Delta E=R_H[\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}][/tex]

And

[tex]\dfrac{hc}{\lambda}=R_H[\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}][/tex]

Plugging all the values we get :

[tex]\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{3745\times 10^{-9}}=2.179\times 10^{-18}[\dfrac{1}{n_f^2}-\dfrac{1}{8^2}]\\\\\dfrac{5.31\times 10^{-20}}{2.179\times 10^{-18}}=[\dfrac{1}{n_f^2}-\dfrac{1}{8^2}]\\\\0.0243=[\dfrac{1}{n_f^2}-\dfrac{1}{64}]\\\\0.0243+\dfrac{1}{64}=\dfrac{1}{n_f^2}\\\\0.039925=\dfrac{1}{n_f^2}\\\\n_f^2=25\\\\n_f=5[/tex]

So, the final level of the electron is 5.

Answer:

remain the same

Explanation:

The pH of the buffer system remain the same when 0.030 moles of strong acid are added because buffer system has the property to resist any change in the pH  when acid or base is added to the solution. In buffer system, one molecule is responsible for neutralizing the pH of the solution by giving H+ or OH-.This molecule is known as buffer agent. If more base is added, the molecule provide H+ and when more acid is added to the solution, then the molecule add OH- to the solution.

Answer:

The two products of this reaction, Sodium Chloride and Potassium Sulfate, are both soluble in water, hence, there's no precipitate formed from this reaction.

Explanation:

Sodium sulfate is Na₂So₄

Potassium Chloride is KCl

When they both react, theres a double displacement where ions and radicals are exchanged

Na₂SO₄ + KCl → NaCl + K₂SO₄

The products are

NaCl - Sodium Chloride

K₂SO₄ - Potassium Sulfate

The two products are soluble in water, hence, there's no precipitate formed from this reaction.

And we would need numerical values of the number of moles of the two reactants mixed to obtain the number of moles of products formed and then the number of molecules from Avogadro's constant.

Hope this Helps!!!

Answer:

3-Pentyn-1-ol

Explanation:

tripple bond is at 3 postion from alochol

carbon are 5 atoms so pent

yn becauese its alkyne

Answer:

14.3 mL  

Explanation:

Assume the student used 0.113 g ascorbic acid  and 0.0900 mol·L⁻¹ NaOH.

1. Balanced chemical equation.

The formula of ascorbic acid is H₂C₆H₆O₆ (MM = 176.12 g/mol).

However, for the balanced equation, let's write it as H₂A.

[tex]\rm H_{2}A + 2NaOH \longrightarrow Na_{2}A + 2H_{2}O[/tex]

2. Moles of ascorbic acid

[tex]\text{Moles of H$_{2}$A} =\text{0.113 g H$_{2}$A} \times \dfrac{\text{1 mmol H$_{2}$A}}{\text{0.176 12 mg H$_{2}$}A} = \text{0.6416 mmol H$_{2}$A}[/tex]

3. Moles of NaOH

The molar ratio is 2 mmol NaOH:1 mmol H₂A.

[tex]\text{Moles of NaOH}= \text{0.6416 mmol H$_{2}$A} \times \dfrac{\text{2 mmol NaOH}}{\text{1 mmol H$_{2}$A}} =\text{1.283 mmol NaOH}[/tex]

4. Volume of NaOH

[tex]V = \text{1.283 mmol NaOH}\times \dfrac{\text{1 mL NaOH}}{\text{0.0900 mmol NaOH}} = \textbf{14.3 mL NaOH}\\\\\text{The student will need $\large \boxed{\textbf{14.3 mL NaOH}}$}[/tex]

Answer:

  0.0480 M

Explanation:

The reaction is ...

  H₂SO₄ + 2NaOH ⇒ Na₂SO₄ +2H₂O

That is, 2 moles of NaOH react with each mole of H₂SO₄. Then the molarity of the H₂SO₄ is ...

  moles/liter = (0.186 M/2)(12.9 mL)/(25.0 mL) ≈ 0.0480 M

Answer:

pH = 7.0

Explanation:

When HCl reacts with NaOH, H₂O and NaCl are produced, thus:

HCl + NaOH → H₂O + NaCl

At equivalence point, all HCl reacts with NaOH. The only you will have is water.

Equilbrium of water is:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

K = 1x10⁻¹⁴ = [H⁺] [OH⁻]

As H⁺ = OH⁻ because both are produced from the same water-

1x10⁻¹⁴ = [H⁺]²

1x10⁻⁷M = [H⁺]

As pH = -log= [H⁺]

-The pH at equivalence point in the titration of a strong acid with a strong base is always 7.0-

Answer:

3.47 ×10^-10

Explanation:

The equation of the reaction is 2Cr3+(aq) + Pb(s)------->2Cr2+(aq) + Pb2+(aq)

A total of two moles of electrons were transferred in the process. The chromium was reduced while the lead was oxidized. Hence the lead species will constitute the oxidation half equation and the chromium will constitute the reduction half equation.

E°cell = E°cathode - E°anode

E°cathode = -0.41 V

E°anode = -0.13 V

E°cell = -0.41 -(-0.13) = -0.28 V

From

E°cell = 0.0592/n log K

n= 2, K= the unknown

-0.28 = 0.0592/2 log K

log K = -0.28/0.0296

log K = -9.4595

K = Antilog ( -9.4595)

K= 3.47 ×10^-10

Answer:

distance = 7 miles

displacement = 5 miles

Explanation:

Distance is a scalar quantity as it takes account of magnitude traveled but not the direction traveled from starting point.

The distance traveled is the sum total of distances moved

distance = 4 + 3 = 7 miles

Displacement however, is a vector and measure the shortest possible distance traveled in a given direction from the starting point.

The path of Elvis' walking forms a right-angle triangle with the hypotenuse being the displacement and the other two sides being the distance traveled west and south.

Using Pythagoras' theorem; c² = a² + b²

where c = hypotenuse and a and b are the other two sides

c² = 4² + 3²

c² = 16 + 9 = 25

√c² = √25

c = 5

Therefore, displacement = 5 miles

Answer:

- Addition of NH₃(g)

- Removal of N₂(g)

- Increase of temperature

- Pressure decrease

Explanation:

According to Le Chatelier's principle, if we apply an stress to a reaction at equilibrium, the system will try to shift the equilibrium in order to decrease the stress. If we add reactants, the equilibrium will shift toward the formation of more products (to the consumption of reactants) and vice versa.

The stresses we can apply to this equilibrium are the following:

- Addition of NH₃(g) : it is a product, thus its addition will result in a shift toward reactants.

- Removal of N₂(g): it is a reactant, thus its removal from the reaction mixture will result in a shift toward reactants.

- Increase of temperature: the reaction is exothermic, so it releases energy. Energy is a product. If we add energy (increase the temperature), we are adding a product, so the equilibrium will shift toward the reactants.

- Pressure decrease: because both reactants and products are in the gas phase. A decrease in pressure shifts an equilibrium to the side of the reaction with greater number of moles of gas. In this case, the reactants side has greater number of moles of gas (1 mol + 3 moles= 4 moles) than the products side (2 moles). Thus, the equilibrum will shift toward reactants.