In the graphic,
X represents which element?
40
20
40x
20
Calcium
Ca
40
Zirconium
60
Neodymium
Nd
Zr

Answer:

D

Explanation:

D shows a double displacment reaction

the other ones show combustion, synthesis and single displacment

Answer:

There is one valence electron in a neutral lithium atom.

Explanation:

The number of valence electrons in a neutral lithium atom is equal to one.

Valence electrons can be described as the electrons filling the outermost shell of an atom while the electrons in the inner shell of an atom are known as core electrons. Lewis structures are used to determine the number of valence electrons and know the types of chemical bonds.

Valence electrons of an atom can be filled in the same or different orbitals and these electrons are responsible for the interaction between atoms and cause the formation of chemical bonds.

Only electrons occupied in the outermost shell can participate in the formation of a bond or a molecule and are responsible for the reactivity of the element.

The number of electrons in the neutral atom of lithium is 3. There is only one electron present on the outermost shell 2s-orbital.

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Answer:I think it’s material chemistry

Explanation:

Answer:

Material chemistry.

Explanation:

Artificial bone and joint replacements is not environmental, it does not have anything to do with farming or such things, and physical chemistry has to do with chemical reactions which is not going on. This leaves materials chemistry.

Answer: The pH of the solution is 2.74.

Explanation:

To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:

[tex]pH=pK_a+\log (\frac{\text{[conjugate base]}}{\text{[acid]}})[/tex]         .......(1)

The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation for it is:

[tex]pK_a=-log K_a[/tex]        ......(2)

The chemical equation for the reaction of acetic acid and NaOH follows:

[tex]CH_3COOH+NaOH\rightleftharpoons CH_3COONa+H-2O[/tex]

Given values:

[tex]K_a=1.8\times 10^{-5}[/tex]

Putting values in equation 2:

[tex]pK_a=-log (1.8\times 10^{-5})\\\\pK_a=4.74[/tex]

We are given:

[tex]CH_3COOH[/tex] = 0.1 M

[tex]CH_3COONa[/tex] = 0.001 M

Plugging values in equation 1:

[tex]pH=4.74+\log (\frac{0.001}{0.1})\\\\pH=4.74-2\\\\pH=2.74[/tex]

Hence, the pH of the solution is 2.74.

Answer:

FADH2 is a reducing agent.

FAD is an oxidizing agent.

Explanation:

The full form of FAD is flavin adenine dinucleotide. It is mainly a redox-active coenzyme which is associated with the different proteins and is involved with the enzymatic reactions in the metabolism.

FAD is obtained by donating or accepting electrons.

In the citric acid cycle,

succinate + FAD → fumarate + [tex]$FADH_2$[/tex]

Thus we see that FAD is an oxidizing agent while [tex]$FADH_2$[/tex] is a reducing agent.      

The balanced reaction is

(Na3PO4)12H2O + 9(BaCl2)2H2O → 6Ba3(PO4)2 + 36NaCl + 10H2O

molar mass of (Na3PO4)12H2O = 380 g/mol

given mass of (Na3PO4)12H2O = 0.990 g

moles of (Na3PO4)12H2O = given mass/molar mass

moles of (Na3PO4)12H2O = 0.990/380= 0.0026 mole

one mole of (Na3PO4)12H2O forms 6 mole of Ba3(PO4)2

0.0026 mole of (Na3PO4)12H2O forms 0.0026×6 =

0.0156 mole of Ba3(PO4)2

mass of 0.0156 moles of Ba3(PO4)2 is = 0.0156 × 601.9 g = 9.40 gram

Answer:

Volume = 4614 m³

Explanation:

The volume of a pyramide is given by the following formula:

We are already given all the required information to calculate the volume by inputting the data:

The pyramid's volume is 4614 cubic meters.

Answer:

Axial position

Explanation:

In the reduction of 4-tert-butylcyclohexanone with sodium borohydride, the major product has the tert-butyl group in the equatorial position and the alcohol in the axial position.

The reason for this is that, axial bonds are parallel to each other. If  substituents are larger than hydrogen, they experience a greater steric crowding in axial compared to the equatorial position. Therefore, many substituted cyclohexane compounds prefer a conformation in which the larger substituents are in equatorial position.

Answer:

1. Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵

2. Kc = [I₂]²

3. Kc = 1/[NH₃] [HCl]

Explanation:

The equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactant raised to their stoichiometric coefficients. It only includes gases and aqueous species.

1. 4 NH₃(g) + 5 O₂(g) ↔ 4 NO(g) + 6 H₂O(g)

Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵

2. ZrI₄(s) ↔ Zr(s) + 2 I₂(g)

Kc = [I₂]²

3. NH₃(g) + HCl(g) ↔ NH₄Cl(s)

Kc = 1/[NH₃] [HCl]

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{3.01 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{3.01}{6.02} \\ = 0.5[/tex]

We have the final answer as

Hope this helps you

Answer:

organic acid

Explanation:

Answer:

Hey mate.....

Explanation:

This is ur answer.....

Alkyl carboxylic acid

Valeric acid (pentanoic acid) is a straight-chain alkyl carboxylic acid with a very unpleasant odor. It is found naturally in the perennial flowering plant valerian (Valeriana officinalis), from which it gets its name.

Hope it helps!

Brainliest pls!

Follow me! :)

Answer:

pH = 12.52

Explanation:

Given that,

The [H+] concentration is [tex]3\times 10^{-13}[/tex].

We need to find its pH.

We know that, the definition of pH is as follows :

[tex]pH=-log[H^+][/tex]

Put all the values,

[tex]pH=-log[3\times 10^{-13}]\\\\pH=12.52[/tex]

So, the pH is 12.52.

Answer:

Mg + 2H₂O —> Mg(OH)₂ + H₂

Explanation:

Mg + H₂O —> Mg(OH)₂ + H₂

The above equation can be balance as illustrated below:

Mg + H₂O —> Mg(OH)₂ + H₂

There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before H₂O as shown below:

Mg + 2H₂O —> Mg(OH)₂ + H₂

Now, the equation is balanced

****Check***

Element >>>>> Reactant >>>> Product

Mg >>>>>>>>>> 1 >>>>>>>>>>> 1

H >>>>>>>>>>> 4 >>>>>>>>>>> 4

O >>>>>>>>>>> 2 >>>>>>>>>>> 2

The balanced equation of Mg + H2O = Mg(OH)2 + H2​ is given as

Mg + 2H₂O —> Mg(OH)₂ + H₂

Generally, the equation for the Chemical equation  is mathematically given as

Mg + H₂O —> Mg(OH)₂ + H₂

Therefore, We se that  we have on the LHS

Mg=1

H=2

O=1

and on The RHS

Mg=1

H=4

O=2

Therefore to balance, we add 2 to H and 1 to O giving

Mg + 2H₂O —> Mg(OH)₂ + H₂

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Answer:

It's 23.14 percent

Explanation:

First, the mass of all the elements are:

N = 14

O = 16

Fe = 56

In this molecule you have 3 atoms of N, and 9 atoms of O, so:

3•14 = 42

16•9 = 144

The whole mass of the molecule is:

56 + 42 + 144 = 242

242/100 = 2.42, so 1% is 2.42

56/2.42 = 23.14%

Answer:

The correct solution is "[tex]0.480 \ J/g^{\circ}C[/tex]".

Explanation:

Given:

q = 103 J

Mass,

m = 12.6 grams

Temperature,

[tex]T_1=22.4[/tex]

[tex]T_2=39.4[/tex]

[tex]\Delta T=T_2-T_1[/tex]

      [tex]=39.4-22.4[/tex]

      [tex]=17^{\circ}C[/tex]

Now,

⇒  [tex]C=\frac{q}{m\times \Delta T}[/tex]

⇒      [tex]=\frac{103}{12.6\times 17}[/tex]

⇒      [tex]=\frac{103}{214.2}[/tex]

⇒      [tex]=0.480 \ J/g^{\circ}C[/tex]

Answer:

Linear

Explanation:

The pOH of the solution containing 9.8×10⁻³ M of hydrogen ion concentration, [H⁺] is 11.99

First, we shall determine the hydroxide ion concentration [OH⁻] in the solution. Details below:

[H⁺] × [OH⁻] = 10¯¹⁴

9.8×10⁻³ × [OH⁻] = 10¯¹⁴

Divide both side by 9.8×10⁻³

[OH⁻] = 10¯¹⁴ / 9.8×10⁻³

[OH⁻] = 1.02×10⁻¹² M

Finally, we shall determine the pOH of the solution. Details below:

pOH = -Log [OH⁻]

pOH = -Log 1.02×10⁻¹²

pOH = 11.99

Thus, from the above calculation, we can conclude that the pOH of the solution is 11.99

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Answer:

D0wnload Phot0Math......................

Explanation:

Answer:

Sulphide ion(S-²) has a -2 charge

Ammonium (NH4+¹) has a +1 charge

When Exchange of Radicals Occur..

The compound formed is

(NH4)2S.

OPTION A IS YOUR ANSWER!

Answer:

NH4)2S

So it is A

Explanation:

Answer:

44.8g

Explanation:

molar mass of k= 39, O= 16, H= 1

molecular mass of KOH= 56g/mol

N=m/Mm

0.8=m/56

m= 0.8×56

m= 44.8g

Mass is "a measure of the amount of matter that an object contains".

Matter is "any substance that has mass and takes up space by having volume".

The formula to calculate the molar mass is M = m/n

where M is molar mass

           m is mass of substance in grams

           n is no. of moles of a substance.

The molecular mass of KOH is 56.105 g/mol

molar mass of K= 39, O= 16, H= 1

M = m/n

 0.8 = m/56.105

    m = 0.8 x 56.105

     m  = 44.8g

Hence, the mass of 0.8 mol of KOH is 44.8g

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Answer:

0m

Explanation:

2m up - 2m down =0m

Answer:

11 grams of atoms are in 0.35 moles of oxygen.

Answer:

+2

Explanation:

I am first with correct answer

Answer:

the oxidation state of iron in FeC2O4 is +2

Answer:

a - carbon is not toxic to living things

Explanation:

The reason carbon dating works is that the fresh carbon-14 gets mixed in with the rest of the carbon in the atmosphere and, since it's chemically identical to regular carbon, gets worked into whatever is presently absorbing atmospheric carbon

Answer:

True

Explanation:

An alcohol is an organic molecule containing an -O-H group. Any molecule which has a hydrogen atom attached directly to an oxygen or a nitrogen is capable of hydrogen bonding.

Answer:

D. Cyclic alkane

Explanation: there is no double or triple bond

The type of molecule that is shown below in the picture is a cyclic alkane. The correct option is D.

This is the compound that contain hydrogen and carbon bond. They are mono cyclic saturated hydrocarbons.

These are the atoms that replace the hydrogen atom in an organic compound.

Thus, the correct option is D. Cyclic alkane.

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Answer:

Chloroplast

Explanation:

Photosynthesis happens in chloroplast of plants. Mitochondira is where the cellular respiration happens.

Answer:

24.24 g

Explanation:

First we calculate how many moles are there in 300 mL of a 0.234 M solution, using the definition of molarity:

Converting 300 mL to L ⇒ 300 mL / 1000 = 0.300 L

Then we convert 0.78 moles of NH₄F into grams, using its molar mass:

Answer:

saltation

Explanation:

Answer:

0.034 L

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 0.055 L

Initial pressure (P₁) = stp = 1 atm

Initial temperature (T₁) = stp = 273 K

Final pressure (P₂) = 2.8 atm

Final temperature (T₂) = 195 °C = 195 °C + 273 = 468 K

Final volume (V₂) =?

The final volume of the gas can be obtained as follow:

P₁V₁ / T₁ = P₂V₂ / T₂

1 × 0.055 / 273 = 2.8 × V₂ / 468

0.055 / 273 = 2.8 × V₂ / 468

Cross multiply

273 × 2.8 × V₂ = 0.055 × 468

764.4 × V₂ = 25.74

Divide both side by 764.4

V₂ = 25.74 / 764.4

V₂ = 0.034 L

Therefore, the new volume of the gas is 0.034 L.