What is the [H+] in a solution with pOH of 0.253? A. 5.58 × 10−15 M B. 1.79 × 10−14 M C. 3.21 × 10−2 M D. 5.58 × 10−1 M

Answer:

Option D. T

Explanation:

Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:

Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)

ΔH = Hp – Hr

From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.

Therefore, the enthalpy change of the reaction is T.

Explanation:

The Answer is a reaction between two acids

Answer:

Weak acid

Explanation:

A titration curve is a graphical description of the change in pH of the solution in the conical flask as the reagent is added from the burette. A titration curve can be plotted for the different kinds of acid and base titrations. The volume of the titrant is always plotted as the independent variable and the pH of the solution as the dependent variable. The equivalence point is read off from the titration curve. A titration curve is very important because it shows the pH at various points during the titration.

A weak acid/strong base titration leads to an equivalence point above 7. From the question, we were told that the pH at equivalence point lies around 8. Hence the unknown substance must be a weak acid.

Answer:

substrate concentration; one-half; the affinity of the substrate-enzyme interaction

Explanation:

The Michaelis constant, Km, refers to the substrate concentration at which a reaction proceeds at one-half of the maximum velocity. This constant most accurately reflects the affinity of the substrate-enzyme interaction.

Answer:

860 J / mol

Explanation:

Enthalpy = Energy / no. of moles

no. of moles = mass / molar mass

Take the atomic mass of H = 1.0,

molar mass of H2 = 1.0 x 2

= 2.0

no. of moles of H2 = 9.00/2

= 4.5 mol

Hence,

Enthalpy = 3870 / 4.5

=860 J / mol

Answer:

The number of atoms in the reactants equals the number of atoms in the products.

Explanation:

In every chemical reaction equation there are two sides; the reactants sides and the products side. The reactants side shows the species that combine to form the products. On both sides of the reaction equation, chemical species are found to be composed of atoms.

The major principle in balancing of chemical reaction equations is that the number of atoms of each element in the reactants side must be equal to the number of atoms of the same element on the products side. Once this condition is achieved, we can now say that the chemical equation is balanced.

Answer:

Answer D: The number of atoms in the reactants equals the number of atoms in the products.

Explanation:

Had the answer plus doing the quiz right now and got it right 100%

Answer:

d)the energy possessed by an electron at a set distance from the nucleus

Answer:

ingredient. U.s unit. SI unit. SI unit(540)

flour. 2cups. ²/6. 180cups = 1.8×10²

milk. 2cups. ²/6. 180cups. =1.8×10²

eggs. 2. ²/6. 180eggs. =1.8×10²

melted butter. ⅓cup ¹/18. 30cups. =3×10¹

sugar. 1spoon. ¹/6. 90spoons. =9×10¹

baking powder 2spoons ²/6. 180spoons. =1.8×10²

salt. ½spoon. ¹/12. 45spoons. =4.5×10¹

Explanation:

1) to get the SI unit divide the U.S unit by 6

example:eggs = 2÷6. =²/6

2) to get the SI unit for 540 people ,multiply the SI unit by 540.

example:eggs ²/6×540. = 180

3)convert the answers to scientific notation

example:eggs =180. =1.8×10²

Answer:

Matter is composed of exceedingly small particles called atoms. An atom is the

smallest unit of an element that can participate in a chemical reaction.

Answer:

Chemical reaction.

Explanation:

Answer: Thus concentration of [tex]Ca(OH)_2[/tex] in [tex]mol/dm^3[/tex]  is 0.011 and in [tex]g/dm^3[/tex] is 0.814

Explanation:

To calculate the concentration of [tex]Ca(OH)_2[/tex], we use the equation given by neutralization reaction:

[tex]n_1M_1V_1=n_2M_2V_2[/tex]

where,

[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HCl[/tex]

[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is [tex]Ca(OH)_2[/tex]

We are given:

[tex]n_1=1\\M_1=0.06mol/dm^3\\V_1=11cm^3=0.011dm^3\\n_2=2\\M_2=?\\V_2=30cm^3=0.030dm^3[/tex]         [tex]1cm^3=0.001dm^3[/tex]

Putting values in above equation, we get:

[tex]1\times 0.06mol/dm^3\times 0.011dm^3=2\times M_2\times 0.030dm^3\\\\M_2=0.011mol/dm^3[/tex]

The concentration in [tex]g/dm^3[/tex] is [tex]0.011mol/dm^3\times 74g/mol=0.814g/dm^3[/tex]

Thus concentration of [tex]Ca(OH)_2[/tex] is [tex]0.011mol/dm^3[/tex] and [tex]0.814g/dm^3[/tex]

Answer:

d

Explanation:

d

Answer:

1) Ba(OH)₂

2) The correct option is a) they conduct electricity.

Explanation:

To deduce the formula of Barium hydroxide, we have to go to the periodic table and look for the Barium (Ba), which is in group 2 and has an ionic charge of 2+. Hydroxides are not an element that is present in the periodic table is the combination of Oxygen and Hydrogen (OH), and its ionic charge is 1-.

To name this substance, we write the elements that form it, which are Ba OH, then we see the ionic charges that they have, Ba2+ OH 1- and we change these charges giving the 2+ to the OH and the 1- to the Ba. It would look Ba OH₂; we do not write the 1, and as there is a 2, the OH, has to be between brackets so that the final formula is Ba(OH)₂. What we did is balancing the charges of the elements. In other words, we need 2 OH for every Ba. Hydroxides give an electron to balance the Ba ionic charge.

Barium Hydroxide is an ionic compound because ionic compounds are formed by a metal (Ba) and a nonmetal element (OH), ionic compounds are charged, so when they are in an aqueous solution they conduct electricity because their ions move freely in the solution.                                          

Answer: The property that cesium most likely would have is being ductile (able to be deformed without losing toughness) due it being a very soft, alkali metal which has a very low melting point of 83.3 °F or 28.5 °C

Answer:

The answer is B. Ductile.

Explanation: Cesium belongs to a category of metals. They are often silver, fairly soft, and very ductile. The answer is right on edge 2020.

Answer:

The solubility of KCl is 1.93 mol/dm³

Explanation:

The information given are;

The mass of the potassium chloride, KCl = 144 g

The volume of the water solvent = 1000 cm³ = 1 dm³

The temperature of the solvent = 90 °C

The atomic mass of potassium, K = 39 u

The atomic mass of chlorine, Cl = 35.5 u

The number of moles of potassium in one mole of potassium chloride, KCl = 1 mole

The number of moles of chlorine in one mole of potassium chloride, KCl = 1 mole

The molar mass of the potassium chloride = 39 + 35.5 = 74.5 g/mol

The number of moles, n, of potassium chloride, KCl in 144 g of potassium chloride, KCl is given as follows

n = Mass/(Molar mass) = 144/74.5 = 1.93 moles

1.93 moles will dissolve in 1 dm³

Therefore, the solubility of KCl is 1.93 mol/dm³.

Answer:

(i) hydrolysis; (ii) combination;  (iii) single replacement;  

(iv) single replacement; (v) double replacement

Explanation:

(i) Carbohydrates are broken down to form glucose

Carbohydrates must react with water to form glucose.

For example,

C₆H₁₁O₅-O-C₆H₁₁O₆ + H-O-H ⟶ 2C₆H₁₂O₆

       maltose                                          glucose

This is a hydrolysis reaction — the reaction of a compound in which a molecule of water breaks one or more bonds to form new substances.

The reaction is not a decomposition (a reaction in which a compound breaks down into two or more simpler substances), because two different molecules are involved.

(ii) Tarnishing of copper.

Cu + S ⟶ CuS

This is a combination or synthesis reaction — in which two or more substances combine to form a single new substance.

(iii) Heating of ferric oxide with aluminium powder

Fe₂O₃ + 2Al ⟶ Al₂O₃ + 2Fe

This is a single displacement or single replacement reaction — in which one element replaces another element in a compound.

Here, Al is replacing Fe in its oxide.

(iv) Blue colour of copper sulphate solution disappears when zinc dust is added to it

CuSO₄ + Zn ⟶ ZnSO₄  + Cu

This is a single displacement or single replacement reaction.

Here, Zn is replacing Cu in its sulfate.

(v) Dilute sulfuric acid is added to sodium hydroxide solution  

H₂SO₄ + 2NaOH ⟶ Na₂SO₄ + 2H₂O

2H⁺, SO₄²⁻ + 2Na⁺OH⁻ ⟶ 2Na⁺, SO₄²⁻ + 2H-OH

This is a double displacement or double replacement reaction — in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.

The Na⁺ ions are replacing the H⁺ ions in the sulfuric, forming sodium sulfate and water,  

Answer:

Explanation:

As per the question, the most rational claim that the student can make about the aluminum metal is that 'it could be stretched into a thin wire' without breaking which shows its ductility. It is one of the most significant characteristics of a metal. Metals can conduct electricity in any state and not only when melted. Thus, option A is wrong. Options C and D are incorrect as metals neither have the same shape always nor do they break on hitting with a hammer. Therefore, option E is the correct answer.

Answer:

Yes, the other person is correct; the answer is E. It could be stretched into a thin wire.

Explanation:

Here is why it is NOT B:

"A briskly burning wood fire is plenty hot enough to melt aluminum. If it's just smoldering (like a lot of campfires) it won't create enough heat to melt aluminum."

Therefore, CAMPFIRES are not likely to melt aluminum if it is thrown in. Aluminum's melting point is 1,221 ° F. Typical campfires are about 900 ° F.

You're Welcome

~Kicho [nm68]

Answer:47.05% is the percent yield of nitrogen in the reaction.

Explanation:

heoretical yield of nitrogen gas = x

Moles of ammonia =  

According to reaction,2 moles of ammonia gives 1 mol of nitrogen gas.

Then 2.3529 mol of ammonia will give:

of nitrogen gas

Mass of 1.1764 moles of nitrogen gas,x = 1.1764 mol × 28 g/mol=32.94 g

Experiential yield of nitrogen gas = 15.5 g

Percentage yield:

hope that help

47.05% is the percent yield of nitrogen in the reaction.

Answer:

The valency of sulphur in SO2 is 4.

Hope this helps..

[tex]good \: luck[/tex]

Answer: The concentration of the KOH solution is 1.01 M

Explanation:

According to neutralization law:

[tex]n_1M_1V_1=n_2M_2V_2[/tex]

where,

[tex]n_1[/tex] = basicity of [tex]HCl[/tex] = 1

[tex]n_2[/tex] = acidity of KOH = 1

[tex]M_1[/tex] = concentration of HCl = 3.00 M

[tex]M_2[/tex] = concentration of KOH = ?

[tex]V_1[/tex] = volume of HCl = 35.3 ml

[tex]V_2[/tex] = volume of KOH = 105.0 ml

Putting the values we get:

[tex]1\times 3.00\times 35.3=1\times M_2\times 105.0[/tex]

[tex]M_2=1.01[/tex]

Thus the concentration of the KOH solution is 1.01 M

Answer:

Thick deposits of sediments carried off of the shelf  

Explanation:

The continental rise is a thick deposit of sediments that accumulate between the continental slope and the abyssal plain

A is wrong. The area of land that drops toward the deep ocean basins is the continental slope.

B is wrong. The 75-mile shallow flat area just off coastlines is the continental shelf.

D is wrong. The surf area along coastlines is the surf zone .

Answer:

3

Explanation:

6.07 has 3 digits and all are significant

Answer:

The correct option is;

Cathode rays are deflected towards a positively charged rod

Explanation:

Cathode rays are  beam of electrons emitted from the cathode in a vacuum tube and moving towards the anode, due to the difference in the voltage between the electrodes

The discovery of the electrons was through the proof by Thomson that cathode rays were a negatively charged, previously unknown particle, which was to become known as the electron.

Answer:

Cathode rays are deflected towards a positively charged rod

Explanation:

i took the exam this is correct

The group 12 elements have different properties than group 13 elements because both have different number of valence electron.

The electron present in valence shell is called valence electron.

The electronic configuration group 12 and group 13 is given below.

Electronic configuration Group 12 = (n-1)d10 ns2

Electronic configuration Group 13 = ns2np1

To learn more about Valence electron here.

https://brainly.com/question/13993867

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Answer:

A

Explanation:

Answer:

11

Explanation:

Data obtained from the question include:

Mass number = 23

Neutron = 12

Atomic number =.?

Next, we shall determine the number of protons present in the element.

This can be achieved by doing the following:

Mass number = Proton + Neutron

Mass number = 23

Neutron = 12

Proton =...?

Mass number = Proton + Neutron

23 = Proton + 12

Collect like terms

Proton = 23 – 12

Proton = 11

The atomic number of an element is equal to the proton number.

Atomic number = proton number

Proton number = 11

Atomic number = proton = 11

Therefore, the atomic number is 11.

Answer:

[tex]molarity =6.9\times 10^{-3}\ M\\[/tex]

Explanation:

We know that , the reaction of HCl and NaOH is given as follows

[tex]NaOH+HCl=NaCl +H_2O[/tex]

Given that

Pressure = 111 mm Hg

[tex]P=111\times 13.6\times 10^{-3}\times 9.81\times 1000=14.809\ kPa[/tex]

Temperature = 20°C

T=20+273=293 K

Volume= 221 m L

V=0.221 L

Number of moles of HCl is given as follows

[tex]n=\dfrac{P\times V}{R\times T}\\n=\dfrac{0.148\times 0.221}{0.821\times 293}=1.3\times 10^{-4}\ moles[/tex]

From the above reaction we can say that

Number of moles of HCl=Number of moles of NaOH

Volume of NaoH is given as follows

V=18.7 = 0.0187 L

Therefore molarity

[tex]molarity =\dfrac{n}{V_{NaOH}}\\molarity =\dfrac{1.3\times 10^{-4}}{0.0187}=6.9\times 10^{-3}\ M\\molarity =6.9\times 10^{-3}\ M\\[/tex]

Answer:

If you follow the periodic table and its orbitals, you'll see that the element that has the electron configuration of 1s²2s²2p³ is Nitrogen. It's period, group, and atomic number are 2, 15, and 7 respectively. The other 2 are Neon, who's period, group, and atomic number are 2, 18, and 10 and the last one is Fluorine, who's period, group, and atomic number are 2, 17, and 9.

Answer:

they won

Explanation:

Answer:

The protons determine the name of an element and also atomic number because its the same as protons.

Answer:

Both the assertion and reason are false

Explanation:

A buffer is a solution that resists changes in acidity and alkalinity. When a solution is buffered, it pH can only vary within a small range. A buffer is made up of a weak acid/base and its salt.

When a strong acid is added to a buffer solution, the conjugate base will react with the H+ from the strong acid to form the undissociated weak acid HA as follows; H+(aq) + A- (aq)→ HA(aq). Hence, H+ concentration decreases owing to its reaction with the A- thus the pH changes only slightly.

At the time when the strong acid should be added so here Both the assertion and reason are false

It is a solution that resists changes with respect to the acidity and alkalinity. When a solution should be buffered, it pH can only change within a small range. At the time when a strong acid should be added to a buffer solution, the conjugate base should be react with the H+ from the strong acid to form the undissociated weak acid.

Learn more about buffer here: https://brainly.com/question/13861408?referrer=searchResults

mg has a 2 in its valence shell

it will become mgcl2

. . . .

: Cl -------- Mg ------ Cl :

. . . .