Why is the first one (A) correct?

Specific chemical element

Answer:

The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.

Explanation:

The pH of the standard hydrogen electrode that has electrode potential of -0.128 V  is 4.3.

The equation of the hydrogen electrode is;

2H^+(aq) + 2e ⇄ H2(g)

The standard electrode potential of hydrogen is 0.00 V

Using the Nernst equation;

Ecell = E°cell - 0.0592/n log Q

Now;

E°cell = 0.00 V

n = 2

Q = 1/[H^+]

-0.128 = 0.00 - 0.0592/2 log  1/[H^+]

-0.128 = 0.00 - 0.0296 log 1/[H^+]

 -0.128 =  - 0.0296 log 1/[H^+]

-0.128/  - 0.0296  =  log 1/[H^+]

1/[H^+] = Antilog (4.32)

[H^+] = 4.79 × 10^-5

Now;

pH = -log[H^+]

pH = -log (4.79 × 10^-5)

pH = 4.3

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This problem is describing the equilibrium whereby the formartion of a complex is attained when 1.47 g of nickel(II) chloride is dissolved in 100.0 mL of ammonia so that the latter's equilibium concentration is 0.20 M. Thus, it is asked to calculate the equilibrium concentrations of both nickel(II) ions and that of the complex.

Firstly, we can write out the chemical equation to be considered:

[tex]Ni^{2+}+6NH_3\rightleftharpoons Ni(NH_3)_6^{2+}[/tex]

Next, we can calculate the initial concentration of nickel(II) ions by using the concept of molarity:

[tex][Ni^{2+}]=\frac{1.47gNiCl_2*\frac{1molNiCl_2}{129.6g}*\frac{1molNi^{2+}}{1molNiCl_2} }{0.1000L}=0.113M[/tex]

Afterwards, we set up an equilibrium expression for this chemical reaction:

[tex]Kf=\frac{[Ni(NH_3)_6^{2+}]}{[Ni^{2+}][NH_3]^6}[/tex]

Which can be written in terms of the reaction extent, [tex]x[/tex]:

[tex]Kf=\frac{x}{(0.113-x)(0.2)^6}[/tex]

Now, for the calculation of [tex]x[/tex], we plug in Kf, and solve for it:

[tex]1.2x10^9=\frac{x}{(0.113-x)(0.2)^6}\\\\1.2x10^9=\frac{x}{(0.113-x)(6.4x10^{-5})}\\\\7.68x10^4(0.113-x)=x\\\\x=0.112999 M[/tex]

Which is about the same to the initial concentration of nickel(II) ions because the Kf is too large.

Thus, the required concentrations at equilibrium are about:

[tex][Ni(NH_3)_6^{2+}]=0.113M[/tex]

[tex][Ni^{2+}]=0M[/tex]

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The correct choice is ~ A

S.I unit of time is Second

The final volume of the methane gas in the container is 6.67 L.

The given parameters;

The total number of moles of gas in the container is calculated as follows;

[tex]n_t = 0.12 + 0.182 = 0.302 \ mol[/tex]

The final volume of gas in the container is calculated as follows;

[tex]PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1 n_2}{n_1} \\\\V_2 = \frac{2.65 \times 0.302}{0.12} \\\\V_2 = 6.67 \ L[/tex]

Thus, the final volume of the methane gas in the container is 6.67 L.

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Answer:

XF3 is our compound. X is unknown For the problem I am using the periodic table at this ...

Explanation:Solution for Element X is an element in period 3. Identify X given that in the molecule XH3, it exhibits hybridization sp2 . Indicate the symbol and not ...

Two or more than two atoms with different physical or chemical properties can not combine together to form an element. The element X  in period 4 with covalency 3 is Arsenic (As).

Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same. The periodic table is divided into groups and periods. depending on the number of valence electrons and the number of outermost orbit respectively.

In the given compound XH[tex]_3[/tex], the covalency of X is 3, means the valence electrons in the outermost shell of element X is 3. The only group that have valence electron 3 is group 15  that is nitrogen family. In the fourth period of group 15 we find Arsenic element.

Therefore the element X  in period 4 with covalency 3 is Arsenic (As).

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In this case, the problem is asking for the balance of a redox reaction in acidic media, in which nickel is reduced to a metallic way and nitrogen oxidized to an ionic way.

Thus, according to the given information, it turns out possible for us to balance this equation in acidic solution by firstly setting up the half reactions:

[tex]Ni^{2+}+2e^-\rightarrow Ni^0\\\\N^{3-}H_4^++3H_2O\rightarrow N^{5+}O_3^-+8e^-+10H^+[/tex]

Next, we cross multiply each half-reaction by the other's carried electrons:

[tex]8Ni^{2+}+16e^-\rightarrow 8Ni^0\\\\2N^{3-}H_4^++6H_2O\rightarrow 2N^{5+}O_3^-+16e^-+20H^+[/tex]

Finally, we add them together to obtain:

[tex]8Ni^{2+}+2N^{3-}H_4^++6H_2O\rightarrow 8Ni^0+2N^{5+}O_3^-+20H^+[/tex]

Which can be all simplified by a factor of 2 to obtain:

[tex]4Ni^{2+}+N^{3-}H_4^++3H_2O\rightarrow 4Ni^0+N^{5+}O_3^-+10H^+\\\\4Ni^{2+}(aq)+NH_4^+(aq)+3H_2O(l)\rightarrow 4Ni(s)+NO_3^-(aq)+10H^+(aq)[/tex]

Hence, the coefficients in front of Ni and H⁺ are 4 and 10 respectively.

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The mass of 5.15 × 10²¹ atoms of chromium is 0.44 g

From Avogadro's hypothesis,

6.02×10²³ atoms = 1 mole of Cr

But:

1 mole of Cr = 52 g

Thus, we can say that:

6.02×10²³ atoms = 52 g of Cr

With the above information, we can obtain the mass of 5.15 × 10²¹ atoms of chromium. This can be obtained as follow:

6.02×10²³ atoms = 52 g of Cr

Therefore,

5.15×10²¹ atoms = (5.15×10²¹ × 52) / 6.02×10²³

5.15×10²¹ atoms = 0.44 g of Cr

Thus, the mass of 5.15 × 10²¹ atoms of chromium is 0.44 g

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Answer:

c. 2-dimethyl-2-butene or 3-dimethyl-1-butene

Answer:

H3PO4 + 3KOH--------->  K3PO4 + 3H2O

Explanation

H3PO4 + KOH------------> K3PO4 + H20

when an hydrogen ion containing acid (HX) reacts with a hydroxide containing base(BOH)  they produce water and a "salt".

water can be called  dihydrogen oxide (H2O), but it can also be called

hydrogen hydroxide (HOH)...same thing.

so the phosphoric acid (H3PO4) contains 3 hydrogen ions (H), and needs 3

hydroxide ions to from 3 hydrogen hydroxides .. that is 3 waters AND A "SALT" WITH THE REMAINING SPECIES ( K AND PO4)      

so let us balance

H3PO4 + 3KOH--------->K3PO4 + 3HOH  or

H3PO4 + 3KOH--------->  K3PO4 + 3H2O

Check:

6 H on the left side, 6 H on the right side

1 P on the left side, 1 P on the right side

3 K on the left side, 3 K on the right side

7 O on the left side, 7 O on the right side

abadabaabdabadaba........that's all folks

yup it is balanced

Answer:

All of the elements are radioactive and contain the transuranium elements.

Explanation:

N/A

Answer:

Step 1-Light Dependent. CO2 and H2O enter the leaf.

Step 2- Light Dependent. Light hits the pigment in the membrane of a thylakoid, splitting the H2O into O2.

Step 3- Light Dependent. ...

Step 4-Light Dependent.

Step 5-Light independent.

Step 6-Light independent.

found a picture hope this helps

Answer:

answer is 4.6×10 with exponent 7

Answer:

[tex]4.6\times10^{-7}[/tex]

Explanation:

Remember that if the decimal point is to the right then the exponent is a negative.

[tex]4.6\times10^{-7}[/tex]

Move the decimal point to the left:

[tex].0.0.0.0.0.0.4.6[/tex]

[tex].0.0.0.0.0.0.4.6=0.00000046[/tex]

Hope this helps

Answer:

Because oil have apolar molecules, while water have polar molecules

The value of the work done in joule is 405.3 J.

We know that the work done is obtained using the relation;

w = PΔV

Where;

w = work done

P = pressure

V = volume

Now, substituting values,

w = 0.800( 15.0 -  10.0)

w = 4 atm L

Since;

1 L atm = 101.325 J

4 atm L  = 4 atm L × 101.325 J/1 L atm

= 405.3 J

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Answer:

The partial pressure of water is much less than 1atm, so the free energy change for the process must be negative with ΔGrxn<0.

Explanation:

Water vapor will condense into liquid water when the water vapor is in its standard state, with a pressure of 1atm. Under normal circumstances, the partial pressure of water vapor is much less that 1atm. It is in a nonstandard state. The free energy change of this reaction has to be negative in order to make the reaction spontaneous.

The criteria of the spontaneous process are the change in the Gibbs free energy should be negative. Above the normal boiling point, the TΔS will be greater than ΔH and ΔG<0.

Gibbs free energy can be described as a state function therefore it doesn’t depend on the path. The change in free energy is equal to the change in enthalpy minus the product of entropy change and temperature of the system.

ΔG = ΔH - Δ (TS)

If the process is carried out at constant temperature, ΔT = 0:

ΔG = ΔH – TΔS

ΔG > 0 for the reaction is non-spontaneous, ΔG < 0 for the reaction is spontaneous, exergonic and ΔG = 0 for the reaction is at equilibrium.

Spontaneous can be described as a reaction that occurs by itself without any external action towards it. The non-spontaneous process needs constant external energy applied to continue and as the external action, the process will cease.

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Answer:

In summary, yeast is a single-celled fungus that uses cellular respiration, which converts glucose and oxygen into carbon dioxide and ATP. ... Aerobic respiration makes the most ATP, between 36 and 38. Fermentation is anaerobic respiration and happens without oxygen.

Answer:

Explanation:

D is the correct answer

Answer:

›› FeBr2 molecular weight. Molar mass of FeBr2 = 215.653 g/mol. This compound is also known as Iron(II) Bromide. Convert grams FeBr2 to moles or moles FeBr2 to grams. Molecular weight calculation: 55.845 + 79.904*2 ›› Percent composition by element

Explanation:

If 38.6 grams of iron react with an excess of bromine gas, the mass of FeBr2 can form is 149 grams.

Mass is defined as a way to gauge how much matter there is in a substance or thing. The kilogram (kg) is the fundamental SI unit of mass, while lower masses can also be measured in grams (g). Atoms make up everyday matter. A majority of an atom's mass is contained in its nucleus.

Given Fe = 38.6 g.

Fe has a molar mass = 55.845 g/mol.

Given mass/molar mass equals 38.6g/55.845gmol-1, or 0.6912 moles of iron.

The reaction is described as Fe + Br2 FeBr2.

One mole Fe yields 1 mole of FeBr2.

FeBr2 would be produced from 0.6912 moles of Fe.

FeBr2 has a molar mass of 215.65 g/mol.

Moles of FeBr2 x Molar mass of FeBr2

= 215.65 g/mole x 0.6912 mole

= 149.06 g FeBr2 produced is the formula.

Thus, if 38.6 grams of iron react with an excess of bromine gas, the mass of FeBr2 can form is 149 grams.

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When the value of secondary quantum number (l) = 1, the magnetic quantum number can be from -1 to +1. The answer would be false.

The angular quantum number (l) can take any integer between 0 and the value of the principal quantum number (n) less by 1.

In other words, l can be from 0 to n-1.

The magnetic quantum number (m), on the other hand, can take any value between -l to +l.

For example, if l = 1, m can be -1,0, and +1.

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My classmate's statement in incorrect because plants are also composed of cells.

All living things are composed of cells. A cell is the smallest unit of living organisms. Cells obtain energy via the process of cellular respiration. During cellular respiration, glucose is broken down to yield carbon dioxide and water.

In photosynthesis, carbon dioxide and water are combined to form glucose. The two processes are opposites of each other. Plants produce their own food via photosynthesis. Since plants are composed of cells, plant cells also undergo cellular respiration therefore my classmate's statement in incorrect.

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Answer:

------------------------------

Explanation:

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Answer: .039L

Explanation:

Answer:

Ionization enthalpy

Explanation:

that should be right

Answer:

´protons: 16

neutrons: 16

name: sulfur

Explanation:

To draw the Lewis dot structure on the [tex]B_aCO_3[/tex] molecular it is necessary to show the electron sharing between the [tex]CO_3[/tex] molecules, and then show the ionic bond between [tex]B_a[/tex] and [tex]CO_3[/tex].

You can see how this is done in the attached image.

We can arrive at this answer because:

Therefore, we can say that [tex]B_a[/tex] forms an ionic bond with [tex]CO_3[/tex].

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Answer:

The mass of objects remains constant throughout the universe. This is because an object is made of he same amount of matter (atoms), no matter where you take it in the universe. If you take an object from the Earth to the moon, only the weight will change.

Explanation:

Answer:

4:6

Explanation: