Answer:
a. NCl3
Explanation:
All the elements stated are non metals. Generally the bond between non metals is a covalent bond. However depending on how the electrons are shared, this bond can either be polar or non polar.
A non polar covalent bond is formed when the electrons are shared equally between the atoms.
A way to determine if a bond is non polar or polar covalent is by comparing the electronegativity values.
If the electronegativity difference is less than 0.5, it is regarded as a non polar covalent bond.
Going back to the question;
Between N and Cl; the electronegativity difference is 3.0 - 3.0 = 0
Between Cl and O; the electronegativity difference is 3.5 - 3.0 = 0.5
Between Cl and P; the electronegativity difference is 3.5 - 2.1 = 1.4
From these we can tell that the correct option is option A.
A hypothetical metal crystallizes with the face-centered cubic unit cell. The radius of the metal atom is 198 picometers and its molar mass is 195.08 g/mol. Calculate the density of the metal in g/cm3.
Answer:
7.38 g/cm³ is the density of the metal
Explanation:
In a Face-centered cubic unit cell you have 4 atoms. Also, the edge length is √8×r (r is radius of the atom).
To solve this problem, we need first to calculate the volume of the unit cell and then, with molar mass calculate the mass of 4 atoms. As density is the ratio between mass and volume we can obtain this value.
Volume of the unit cellVolume = a³
a = √8×r
(r = 198x10⁻¹²m)
a = 5.6x10⁻¹⁰ m
Volume = 1.756x10⁻²⁸ m³
1m = 100cm → 1m³ = (100cm)³:
1.756x10⁻²⁸ m³× ((100cm)³ / 1m³) =
1.756x10⁻²² cm³ → Volume of the unit cell in cm³Mass of the unit cell:There are 4 atoms of gold:
4 atoms × (1mol / 6.022x10²³ atoms) = 6.64x10⁻²⁴ moles of gold
As 1 mole weighs 195.08g:
6.64x10⁻²⁴ moles of gold × (195.08g / mol) =
1.296x10⁻²¹g is the mass of the unit cellDensity of the metal:1.296x10⁻²¹g / 1.756x10⁻²² cm³ =
7.38 g/cm³ is the density of the metalThe density of the metal is 7.40 g/cm³
In cubic crystal system, face-centered cubic FFC is the name given to sort of atom arrangement observed in which structure is made up of atoms organized in a cube with a portion of an atom in each corner and six extra atoms in the center of each cube face.
It is expressed by using the formula:
[tex]\mathbf{\rho = \dfrac{Z \times M}{N_A\times a^}}[/tex]
where;
[tex]\rho[/tex] = density of the metalZ = atoms coordination no = 4 (for FCC)Molar mass (M) = 195.8 g/molAvogadro's constant (NA) = 6.022 × 10²³ /mola = edge lengthFor face-centered cubic FFC;
The edge length [tex]\mathbf{a =2 \sqrt{2}\times r }[/tex]
[tex]\mathbf{a =2 \sqrt{2}\times 198 \ pm }[/tex]
[tex]\mathbf{a =560.0285 \ pm }[/tex]
a = 5.60 × 10⁻⁸ cm
Replacing it into the previous equation, we have:
[tex]\mathbf{\rho = \dfrac{4 \times 195.8}{6.022 \times 10^{23} \times( 5.60 \times 10^{-8} )^3}}[/tex]
[tex]\mathbf{\rho = 7.40\ g/cm^3 }[/tex]
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By heating a 93% pure kclo3 sample, what percentage of its mass is reduced?
2KCLO3---->2KCL+3O2
Explanation:
free your mind drink water and go outside take fresh air you will get answers
There are approximately 2 × 1022 molecules and atoms in each breath we take and the concentration of CO in the air is approximately 9 ppm. How many CO molecules are in each breath we take? solution
Answer:
1.8x10¹⁷ molecules of CO are in each breath we take
Explanation:
Parts per million, ppm, is an unit of concentration in chemistry used for very diluted solutions.
A 9ppm of X in a solution means in 1 million of molecules (1x10⁶) you have only 9 molecules of X.
In a breath we have 2x10²² molecules and 9 ppm are CO. Thus, CO molecules in each breath are:
2x10²² molecules × (9 molecules CO / 1x10⁶ molecules) =
1.8x10¹⁷ molecules of CO are in each breath we take[tex]1.8\times 10^{17}[/tex] molecules of CO are in each breath we take
The calculation is as follows:A 9ppm of X in a solution represent in 1 million of molecules[tex](1\times10^6)[/tex]you have only 9 molecules of X.
Now CO molecules in each breath is
[tex]= 2\times 10^{22}\ vmolecules \times (9\ molecules\ CO \div 1\times 10^6 molecules) \\\\= 1.8\times 10^{17}[/tex]
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Read the following statement:
Energy cannot be created or destroyed.
Does the statement describe a scientific law? (3 points)
a
No, because it universally applies to all objects
b
No, because it is not true in all circumstances
c
Yes, because it universally applies to all objects
d
Yes, because it is not true in all circumstances
Answer:
C. yes, because it is universally applies to all objects
What is the amount of heat required to change one mole of a substance from the solid to liquid state known as?
Select the correct answer below:
A) the enthalpy of fusion
B) the melting point
C) the entropy of disorder
D) none of the above
A) the enthalpy of fusion
Explanation:
the heat of vaporization, is the amount of energy needed to change a liquid to a gas at constant temperature and pressure. The energy required to melt a solid to a liquid is called the heat of fusion, and the heat of sublimation is the energy.
Answer:
A
Explanation:
In the reaction of Zn(s) + 2HCl (aq) Imported Asset ZnCl2 (aq) + H2 (g), if [HCl] increases from 2.6 M to 8.2 M:
The rate at which Zn disappears decreases.
The rate at which H2 appears decreases.
The rate at which ZnCl2 appears increases.
The concentration of Zn (s) also increases.
Answer:
The rate at which ZnCl2 appears increases.
Explanation:
Hello,
In this case, the reaction is:
[tex]Zn(s) + 2HCl (aq) \rightarrow ZnCl_2 (aq) + H_2 (g)[/tex]
Therefore, the law of rate proportions is:
[tex]\frac{1}{-1}r_{Zn}= \frac{1}{-2}r_{HCl}= \frac{1}{1}r_{ZnCl_2}= \frac{1}{1}r_{H_2}}[/tex]
In such a way, since the concentration of hydrochloric acid is increasing The rate at which ZnCl2 appears increases, because the addition of a reactant is directly related with the products formation due to the fact that more reactant will yield more product.
Best regards.
Name the following alkane molecule:
A. methylpentane
B. 2-methylpentane
C. 2-ethylpentane
Answer:
B
Explanation:
its upside down but I'm 99% sure
Name four types of salts
Answer:
Any ionic molecule formed of a base and an acid, which dissolves in water to produce ions is known as a salt. The four common types of salts are:
1. NaCl or sodium chloride is the most common kind of salt known. It is also known as table salt.
2. K2Cr2O7 or potassium dichromate refers to an orange-colored salt formed of chromium, potassium, and oxygen. It is toxic to humans and is also an oxidizer, which is a fire hazard.
3. CaCl2 or calcium chloride looks like table salt due to its white color. It is broadly used to withdraw ice from roads. It is hygroscopic.
4. NaHSO4 or sodium bisulfate produces from hydrogen, sodium, oxygen, and sulfur. It is also known as dry acid. It has commercial applications like reducing the pH of swimming pools and spas and others.
For the reaction 3H 2(g) + N 2(g) 2NH 3(g), K c = 9.0 at 350°C. What is the value of ΔG at this temperature when 1.0 mol NH 3, 5.0 mol N 2, and 5.0 mol H 2 are mixed in a 2.5 L reactor?
Answer:
ΔG = - 31.7kJ/mol
Explanation:
It is possible to find ΔG of a reaction at certain temperature knowing Kc following the equation:
ΔG = ΔG° + RT ln Q
ΔG° = -RT lnKc
ΔG = -RT lnKc + RT ln Q (1)
Where R is gas constant (8.314J/molK), T absolute temperature (350°C + 273.15 = 623.15K) and Q reaction quotient
For the reaction,
3H₂(g) + N₂(g) ⇄ 2NH₃(g)
Q = [NH₃]² / [H₂]³[N₂]
Where the concentrations of each chemical are:
[NH₃] = 1.0mol / 2.5L = 0.4M
[H₂] = 5.0mol / 2.5L = 2M
[N₂] = 2.5mol / 2.5L = 1M}
Q = [0.4M]² / [2M]³[1M]
Q = 0.02
And replacing in (1):
ΔG = -RT lnKc + RT ln Q
ΔG = -8.314J/molK*623.15K ln 9 + 8.314J/molK*623.15K ln 0.02
ΔG = - 31651J/mol
ΔG = - 31.7kJ/molWhich method separates components of a mixture according to how quickly the particles travel through a medium?
A. distillation
B. evaporation
C. filtration
D. chromatography
Taking into account its definition, the correct answer is option D) Chromatography.
Chromatography is a method that allows the separation, identification and determination of chemical components in complex mixtures. By means of a chromatography it is possible to separate analytes that are very similar to each other in terms of their physico-chemical properties.
For the separation to occur, the principle of selective retention is used, which consists of the different behavior of the components of a mixture on a specific support (such as paper, a gas, a liquid) and a flowing liquid or gaseous phase. through the bracket.
In other words, there is a stationary phase immobilized on a support and a mobile phase that will drag the sample through the stationary phase. During this process, each component of the sample will move according to its own physicochemical characteristics. The general concept will be that those components that prefer the stationary phase are more retained, while those that prefer the mobile phase will move faster.
In summary, the components of the sample are distributed between two phases of different nature, as a consequence of the speed variation that is established when being dragged by a mobile, liquid or gaseous phase, through a stationary, solid or liquid phase.
Finally, the correct answer is option D) Chromatography.
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Which of the following best describes physical science?
0...
OA.
the study of motion
OB.
the study of matter and energy
O C.
the study of Earth's structure and processes
OD.
the study of reactions
O E.
the study of living things
Reset
Ne
B. The study of matter and energy.
Because physical science is everything that doesn't include organic things.
The study of matter and energy among the following best describes physical science.
What is matter?
Matter in chemistry, is defined as any kind of substance that has mass and occupies space that means it possess volume .Matter is composed up of atoms which may or not be of same type.
Atoms are further made up of sub atomic particles which are the protons ,neutrons and the electrons .The matter can exist in various states of substances such as solids, liquids and gases depending on the conditions of the temperature and the pressure.
The states of matter are inter convertible into each other by changing the parameters of temperature and pressure.Matter is always conserved by law of conservation of matter.The law was proposed by Antoine Lavoisier.
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The intermolecular forces present in CH 3NH 2 include which of the following? I. dipole-dipole II. ion-dipole III. dispersion IV. hydrogen bonding
Answer:
I. dipole-dipole
III. dispersion
IV. hydrogen bonding
Explanation:
Intermolecular forces are weak attraction force joining nonpolar and polar molecules together.
London Dispersion Forces are weak attraction force joining non-polar and polar molecules together. e.g O₂, H₂,N₂,Cl₂ and noble gases. The attractions here can be attributed to the fact that a non -polar molecule sometimes becomes polar because the constant motion of its electrons may lead to an uneven charge distribution at an instant.
Dispersion forces are the weakest of all electrical forces that act between atoms and molecules. The force is responsible for liquefaction or solidification of non-polar substances such as noble gas an halogen at low temperatures.
Dipole-Dipole Attractions are forces of attraction existing between polar molecules ( unsymmetrical molecules) i.e molecules that have permanent dipoles such as HCl, CH3NH2 . Such molecules line up such that the positive pole of one molecule attracts the negative pole of another.
Dipole - Dipole attractions are more stronger than the London dispersion forces but weaker than the attraction between full charges carried by ions in ionic crystal lattice.
Hydrogen Bonding is a dipole-dipole intermolecular attraction which occurs when hydrogen is covalently bonded to highly electronegative elements such as nitrogen, oxygen or fluorine. The highly electronegative elements have very strong affinity for electrons. Hence, they attracts the shared pair of electrons in the covalent bonds towards themselves, leaving a partial positive charge on the hydrogen atom and a partial negative charge on the electronegative atom ( nitrogen in the case of CH3NH2 ) . This attractive force is know as hydrogen bonding.
Answer:
The intermolecular forces present in CH_3NH_2 includes
II. (ion-dipole) and IV. (hydrogen bonding)Explanation:
The intermolecular forces present in CH_3NH_2 includes II. (ion-dipole) and IV. (hydrogen bonding)
It is a polar molecule due to NH polar bond and it can form Hydrogen bond also due to NH bond.
Interaction will be dipole- dipole and Hydrogen dispersion forces can always be taken into account.
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A variation of the acetamidomalonate synthesis can be used to synthesize threonine. The process involves the following steps: Ethoxide ion deprotonates diethyl acetamidomalonate, forming enolate anion 1; Enolate anion 1 makes a nucleophilic attack on acetaldehyde, forming tetrahedral intermediate 2; Protonation of the oxyanion forms alcohol 3; Acid hydrolysis yields dicarboxyamino alcohol 4; Decarboxylation leads to the final amino acid. Write out the mechanism on a separate sheet of paper, and then draw the structure of tetrahedral intermediate 2.
Answer:
See figure 1
Explanation:
For this reaction, we have the production of a carbanion as the first step. The base "ethoxide" can remove a hydrogen-producing a negative charge in the carbon (enolate anion 1). Then this negative charge can attack the carbon of the carbonyl group in the molecule acetaldehyde and the tetrahedral intermediate 2 is form. In the next step, we have the protonation of the oxygen to produce alcohol 3. A continuation we have the hydrolysis of the ester groups to produce the Dicarboxyamino alcohol and finally, we have a decarboxylation reaction we will produce the amino acid Threonine.
To further explanations see figure 1
I hope it helps!
which of the following is is a chemical property of pure water
Answer:
Pure water has an acidity of about 7 on the pH scale. -is a chemical property of pure water. Pure water has an acidity of about 7 on the pH scale
Answer: không màu , không mùi không vị
Explanation:
Select all of the following statements that represent the differences between a voltaic cell and an electrolytic cell. Group of answer choices The electrodes will change in mass for only the electrolytic cell Reduction happens at the cathode for only the electrolytic cell The redox reaction is spontaneous for only voltaic cell Electrode with the lowest reduction potential is reduced in an electrolytic cell A potential is generated when the voltaic cell runs
Answer:
The electrodes will change in mass for only the electrolytic cellElectrode with the lowest reduction potential is reduced in an electrolytic cellA potential is generated when the voltaic cell runsThe following statements represent the differences between a voltaic cell and an electrolytic cell -
The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsThe process occurs spontaneously in the voltaic cells due to chemical reactions.electrolytic cell electrical energy is needed for the chemical reactions to occur.A potential is generated by a chemical reaction and for electrolytic cells, a potential is needed.
there is definitely an exchange of mass in a voltaic cellthe species with lower reduction potential always gets reduced and in any electrochemical cell reduction occurs at the cathode.The following statements represent the differences between a voltaic cell and an electrolytic cell -
The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsThus, The following statements represent the differences between a voltaic cell and an electrolytic cell -
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Which of the following pieces of information is given in a half-reaction?
O A. The number of electrons transferred in the reaction
B. The compounds that the atoms in the reaction came from
C. The state symbol of each compound in the reaction
D. The spectator ions that are involved in the reaction
Answer:
The number of electrons transferred in the reaction
Explanation:
Answer:
A
Explanation:
The decomposition of nitramide in aqueous solution at 25 °C NH2NO2(aq)N2O(g) + H2O(l) is first order in NH2NO2 with a rate constant of 4.70×10-5 s-1. If an experiment is performed in which the initial concentration of NH2NO2 is 0.384 M, what is the concentration of NH2NO2 after 31642.0 s have passed? M
Answer:
[tex][NH_2NO_2]=0.0868M[/tex]
Explanation:
Hello,
In this case, for the given chemical reaction, the first-order rate law is:
[tex]r=\frac{d[NH_2NO_2]}{dt} =-k[NH_2NO_2][/tex]
Which integrated is:
[tex][NH_2NO_2]=[NH_2NO_2]_0exp(-kt)[/tex]
Thus, the concentration after 31642.0 s for a 0.384-M solution is:
[tex][NH_2NO_2]=0.384M*exp(-4.70x10^{-5}s^{-1}*31642.0s)\\[/tex]
[tex][NH_2NO_2]=0.0868M[/tex]
Best regards.
Answer:
[A] = 0.0868 M
Explanation:
Rate constant = 4.70×10-5 s-1
First order reaction
Initial concentration, [A]o = 0.384 M
Final concentration, [A] = ?
Time, t = 31642.0 s
All these variables are related by the following equation;
[A] = [A]o e^(-kt)
[A] = 0.384 e^(-4.70×10-5 x 31642.0)
[A] = 0.384 e^(-1.4872)
[A] = 0.384 * 0.2260
[A] = 0.0868 M
Which of the following best describes a limiting reactant? a. The reactant that limits the rate (or speed) of a chemical reaction. b. The reactant that limits the position of equilibrium in a reversible chemical change. c. The reactant that remains at the end of the reaction. d. The reactant that can produce the greatest amount of product. e. The reactant that is completely used up by a reaction.
Answer:
e is the suitable answer for that. I think it is correct.
Answer: The correct option is E ( the reactant that is completely used up by a reaction).
Explanation:
A LIMITING REACTANT can be defined as the reagent or the substance that is involved in a chemical reaction which determines when the reaction will stop. This is because it is COMPLETELY used up in the reaction. Reactants that are called limiting reactants is because the quantity of these reagents are capable of limiting the amount of products formed. And by doing so, the chemical reaction cannot proceed further with the absence of this reactant. Using an attached diagram below to illustrate further:
The reagents D and E reacts to form F as the product. In this reaction, reactant E is the limiting reagent because there is still some left over D in the products. Therefore, D was in excess when E was all USED UP.
Therefore the CORRECT option is E which states that the reactant that is completely used up by a reaction, best describes a limiting reactant.
Option A is WRONG because it's the concentration of both reactants in chemical equation can limit the speed of that reaction.
Option B is WRONG because it's when the concentration of a particular reactant is either increased or decreased can affect the position of equilibrium.
Option C and D are wrong because the reactant that remains in the end of a reaction and can produce the greatest amount of product is the one in EXCESS.
What subatomic particles surround the nucleus? Question 1 options: protons neutrons atoms electrons
Answer:
Electrons "surround"
Explanation:
Protons and neutrons "make up" the nucleus so they are contained "within" the nucleus meaning that electrons would "surround" the nucleus as they orbit around the nucleus
Answer:
Electrons
Explanation:
Protons and nuetrons are present inside the nucleus of an atom while the electron revolve around the nucleus in different energy levels.
Provide the name(s) for the tertiary alcohol(s) with the chemical formula C6H14O that have a 4-carbon chain. Although stereochemistry may be implied in the question, DO NOT consider stereochemistry in your name. Alcohol #1______ Alcohol #2: ______Alcohol #3______
Answer:
Explanation:
A tertiary alcohol is a compound (an alcohol) in which the carbon atom that has the hydroxyl group (-OH) is also bonded (saturated) to three different carbon atoms.
Based on the question, the only tertiary alcohol that can result from C₆H₁₄O that have a 4-carbon chain is
2-hydroxy-2,3-dimethylbutane
H OH H H
| | | |
H - C - C - C - C - H
| | | |
H CH₃ CH₃ H
From the above, we can see that the carbon atom having the hydroxyl group is also bonded to three other carbon atoms. And since we aren't considering stereochemistry, this is the only tertiary alcohol we can have with a 4-carbon chain
A bio catalyst that increases the rate of the reaction without being changed
a) Aluminum oxide. b) Silicon dioxide. c) Enzyme. d) Hydrogen peroxide
43. What is the
than the reaction substrate.
42. A
Explanation:
Enzymes are proteins functioning as catalysts that speed up reactions by lowering the activation energy. A simple and succinct definition of an enzyme is that it is a biological catalyst that accelerates a chemical reaction without altering its equilibrium.
A 1.00 liter flask initially contained 0.24 mol NO2 at 700 K which decomposed according to the following equation. When equilibrium was achieved, 0.14 mol NO was present. Calculate Kc. 2NO2(g) ↔ 2NO(g) + O2(g)
Answer:
[tex]Kc=0.14[/tex]
Explanation:
Hello,
In this case, for the given reaction, the equilibrium expression is:
[tex]Kc=\frac{[NO]^2[O_2]}{[NO_2]^2}[/tex]
That in terms of the reaction extent [tex]x[/tex] is written as (initial concentration of NO2 is 0.24 M for 0.24 mol in 1.00 L):
[tex]Kc=\frac{(2*x)^2(x)}{(0.24M-2*x)^2}[/tex]
Moreover, since at the equilibrium 0.14 moles of NO are present (a 0.14-M concentration), we can compute the reaction extent as shown below:
[tex][NO]=2*x=0.14M[/tex]
[tex]x=0.14M/2=0.07M[/tex]
In such a way, knowing [tex]x[/tex], we compute Kc as shown below:
[tex]Kc=\frac{(2*0.07)^2(0.07)}{(0.24M-2*0.07)^2}\\\\Kc=0.14[/tex]
Regards.
The kc is 0.14.
Equivalent expression:Since
[tex]Kc = \frac{[NO]^2[O_2]}{[NO_2]^2}\\\\[/tex]
Here the reaction extent x should be written like the initial concentration of NO2 is 0.24 M for 0.24 mol in 1.00 L.
Now
[tex]Kc = \frac{(2\times\ x)^2}{(0.24M - 2\times x)^2}[/tex]
Since at the equilibrium 0.14 moles of NO are presented so the reaction should be
NO = 2*x = 0.14m
x = 0.07
Now kc should be
[tex]= \frac{(2\times 0.07)^2 (0.07)}{(0.24M - 2\times 0.07)^2}[/tex]
= 0.14
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Why must beta particles be used to detect leaks in a pipe?
Why must beta particles be used to detect leaks in a pipe?
A. Beta particles will not be absorbed by the soil like gamma radiation, but won't pass through the pipe before reaching the leak like alpha radiation would.
B. Beta particles will not cause an electrical discharge like alpha particles when they interact with the metal pipe, or contaminate the water like gamma radiation.
C. Beta particles are not used, only alpha particles are used because they are not harmful to humans.
D. Beta particles will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak like gamma radiation would.
Should be D, because alpha particles are absorbed by soil and gamma isn't
Beta particles will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak.
What is Beta particle?This type of particle is a high-speed electron and is derived from the process of beta decay.
It is used to detect leaks in pipe because it will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak like gamma radiation would.
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An object has a mass of 4.9g and a volume of 14.ml.what is the density of the object?
Answer:
0.35 g/mL
Explanation:
Use the formula D = [tex]\frac{m}{v}[/tex], where D is density, m is mass, and v is volume.
D = 4.9/14
D = 0.35
D = 0.35 g/mL
g Does a reaction occur when aqueous solutions of barium hydroxide and aluminum sulfate are combined
Answer:
3BaO + Al₂(SO₄)₃ → Al₂O₃+ 3BaSO₄
Explanation:
Yes! A reactiin occurs between barium hydroxide and auminium sulphate.
barium sulfate (BaSO4) and aluminum hydroxide (Al(OH)3) are the products obtained in this reaction.
The reaction is given by the equation below;
3BaO + Al₂(SO₄)₃ → Al₂O₃+ 3BaSO₄
Two elements represents by the letter Q and R atomic number 9 and 12 respectively. Write the electronic configuration of R
Answer:
Atomic no = 12 = Mg
Explanation:
It is given that,
The atomic number of two elements that are represented by letter Q and R are 9 and 12.
We need to write the electronic configuration of R. Atomic number shows the number of protons in atom.
For R, atomic number = 12
Its electronic configuration is : 2,8,2
It has two valance electrons in its outermost shell. The element is Magnesium (Mg).
g What is the molarity of hydrochloric acid if 40.95 mL of HCl is required to neutralize 0.550 g of sodium oxalate, Na2C2O4
Answer:
0.0002 M
Explanation:
The molarity of the HCl required would be 0.0002 M.
First, let us consider the balanced equation of the reaction:
[tex]Na_2C_2O_4 + 2HCl = 2NaCl + H_2 + 2CO_2[/tex]
Stoichiometrically, 1 mole of [tex]Na_2C_2O_4[/tex] reacts with 2 moles of [tex]HCl[/tex] for a complete neutralization reaction.
Recall that: mole = [tex]\frac{mass}{molar mass}[/tex]
Mole of 0.550 g sodium oxalate = 0.550/134 = 0.0041 mole
If 1 mole [tex]Na_2C_2O_4[/tex] requires 2 moles HCl, then 0.0041 mole will require:
0.0041 x 2 = 0.0082 mole HCl
Volume of the HCl = 40.95 L
Molarity = mole/volume
Hence, molarity of the HCl = 0.0082/40.95 = 0.0002 M
Predict the most likely bond type for the following.
a. Cu (Copper)
b. KCl (Potassium Chloride)
c. Si (Silicon)
d. CdTe (Cadmium Telluride)
e. ZnTe (Zinc Telluride)
Answer:
The three major types of bond are ionic, polar covalent, and covalent bonds. Ionic occurs majorly between metals and non-metals, which allows sharing of electrons to form an ionic compound. Whereas covalent bonding calls for complete transfer of electrons between atoms. Polar covalent bonds have unequaly shared electron-pair between two atoms.
Explanation:
a. Cu (Copper)- ionic bonding
b. KCl (Potassium Chloride) - ionic bonding
c. Si (Silicon) - covalent bonding
d. CdTe (Cadmium Telluride) - polar covalent bonding
e. ZnTe (Zinc Telluride)- polar covalent bonding
One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this:
Answer:
6.5 mg/L.
Explanation:
Step one: write out and Balance the chemical reaction in the Question above:
NiCl2 + 2AgNO3 =====> 2AgCl + Ni(NO3)2.
Step two: Calculate or determine the number of moles of AgCl.
So, we are given that the mass of AgCl = 3.6 mg = 3.6 × 10^-3 g. Therefore, the number of moles of AgCl can be calculated as below:
Number of moles AgCl = mass/molar mass = 3.6 × 10^-3 g / 143.32. = 2.5118 × 10^-5 moles.
Step three: Calculate or determine the number of moles of NiCl2.
Thus, the number of moles of NiCl2 = 2.5118 × 10^-5/ 2 = 1.2559 × 10^-5 moles.
Step four: detemine the mass of NiCl2.
Therefore, the mass of NiCl2 = number of moles × molar mass = 1.2559 × 10^-5 moles × 129.6 = 1.6 × 10^-3 g.
Step five: finally, determine the concentration of NiCl2.
1000/ 250 × 1.6 × 10^-3 g. = 6.5 mg/L.
g Which ONE of the following molecules and ions has trigonal planar molecular geometry? (NOTE: You must first determine what the Lewis structure of each substance is.) A) PCl3 B) HCN C) CO3 2– D) H3O+ E) NF3
Answer: C) [tex]CO^{2-}_{3}[/tex]
Explanation: The Valence Shell Electron Pair Repulsion Model (VSEPR Model) shows bonding and nonbonding electron pairs present in the valence, outermost, shell of an atom connecting to other atoms. It also gives the molecular geometric shape of a molecule.
To determine molecular geometry:
1) Draw Lewis Structure, i.e., a simplified representation of the valence shell electrons;
2) Count the number of electron pairs (count multiple bonds as 1 pair);
3) Arrange electron pairs to minimise repulsion;
4) Position the atoms to minimise the lone pair;
5) Name the molecular geometry from the atom position;
Trigonal planar molecular geometry is a model which molecule's shape is triangular and in one plane. Such molecule has three regions of electron density extending out from the central atom and the repulsion will be at minimum when angle between any two is 120°.
The Lewis structure of each molecule is shown in the attachment.
Analysing each one, it can be concluded that molecule with trigonal planar geometry is [tex]CO^{2-}_{3}[/tex]