Answer:
c and d are correct
Explanation:
In A, false because in Valence Electrons, the more the valences, the more stable an atom is.
In B, false because atoms cannot readily gain or lose valence electrons as the number of valence electrons is determined by the column they are in.
In C, true because the more the valence electrons, the more the stability of an atom.
In D, true as electron placing is important and the reactivity of an atom is important.
So C and D are true!
The statement(s) which are true about valence electrons are:
c. Atoms are stable when they have as many valence electrons as possible.
d. Valence electrons determine many of the properties of an atom.
An atom refers to the smallest, indivisible unit that isnmade up of matter and forms all chemical elements.
In Chemistry, an atom comprises three (3) distinct particles and these are;
Protons. Neutrons. Electrons.Valence electrons is simply the number of electrons that is/are present in the outermost shell of the atom of a chemical element.
Generally, valence electrons are typically used to determine whether an atom or group of chemical elements can bond with other chemical elements.
As a general rule, atoms with as many valence electrons as possible are more stable and reaches an octet state.
Lastly, valence electrons are used to determine the chemical properties of of the atom of a chemical element.
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What is the change in the internal energy of a system that does 100 joules of
work and absorbs 1,000 joules of heat?
Answer:900j
Explanation:
How something works is related to its structure
Answer:
Forms and Functions
Explanation:
It refers to the direct relationship between the structure of a thing and the way it functions.
What is The compound with the formula SiCl4
Answer:
silicon tetrachloride or tetrachlorosilane
Other than the starting material, 2-methylcyclohexanol, what base or bases are present in the dehydration reaction mixture to participate in proton transfers?
a) H2PO4- only
b) H2O and H2PO4-
c) H2O and HSO4-
d) H2O only
Answer:
c) H2O and HSO4-
Explanation:
The dehydration of 2-methylcyclohexanol occurs in the presence of H2SO4. Recall that acids are proton donors in solution; the equilibrium shown below is then set up,
H2SO4(aq) + H2O(l) ⇄H3O^+(aq) + HSO4^-(aq)
The species H2O and HSO4- are two proton acceptors in the system. According to the Brownstead- Lowry definition, a base is a proton acceptor in solution.
Hence H2O and HSO4- are bases present in the dehydration of 2-methylcyclohexanol.
Which of these compounds do not have a pH dependent solubility at less than pH 7.00?
Answer:
tbh idekkk
Explanation:
What is the molality of 6 grams of salt in 10 grams of solution?
Answer:
maalat ang salt
Explanation:
What does this image represent?
Amine group
Carbonyl group
Ether group
Hydroxyl group
Answer:
ether group
Explanation: I looked it up
The following concerns the combustion of nitromethane (CH3NO2 - a popular fuel for top-fuel dragsters) according to the reaction below:_______. 2 CH3N02 (1) + ž02(g) → 2C02) + 3H20 (1) + N2(9) a. Burning 121 L of nitromethane at constant pressure releases 1.6 x 100 kJ of energy. What is the enthalpy of combustion of this reaction? The density of nitromethane is 1.16 g/cm². b. Assume you transfer heat involved in the previous problem to 1 kL of water that is initially at 25.0 °C. What is the final temperature of the water?
Answer:
695.8kJ/mol = Enthalpy of combustion
Final temperature = 407.4°C
Explanation:
Taken the reaction:
2CH₃NO₂ + 3/2 O₂ → 2CO₂ + 3H₂O + N₂
The enthalpy of the reaction is the heat released when 1 mole of nitromethane are in combustion.
We need to find the moles presents in 121L of nitromethane using its density and molar mass (61.04g/mol). As these moles releases 1.6x10⁶kJ, we need to find heat released per mole of nitromethane
Mass nitromethane:
121L = 121000cm³ * (1.16g/cm³) = 140360g
Moles:
140360g * (1mol / 61.04g) = 2299.5 moles of nitromethane
Heat released per mole of nitromethane:
1.6x10⁶kJ / 2299.5 mol = 695.8kJ/mol = Enthalpy of combustion
The symbol - is because the heat is released, a + symbol is when the heat is absorbed.
Using:
Q = m×C×ΔT
Where Q is heat (1.6x10⁶kJ = 1.6x10⁹J)
m is mass of water:
1kL = 1000L = 1x10⁶mL = 1x10⁶g
C is specific heat of water: 4.184J/g°C
And ΔT is change in temperature.
Solving for ΔT:
1.6x10⁹J = 1x10⁶g * 4.184J/g°C * ΔT
ΔT = 382.4°C
As initial temperature was 25°C, final temperature is:
382.4°C + 25°C =
407.4°C
The compound stannous(II) nitride is incorrectly named. Rename the compound correctly.
Answer:
Answer: Tin (II) nitride
Show by calculation which process produces more energy per gram of material reacting
Part A Calculate the [H3O+] of the following polyprotic acid solution: 0.300M H3PO4. Express your answer using two significant figures.
Part B Calculate the pH of this solution.
Express your answer using one decimal place.
Part C Calculate the [H3O+] and pH of the following polyprotic acid solution: 0.310M H2C2O4.
Express your answer using two significant figures.
Part D Calculate the pH of this solution.
Express your answer using two decimal places.
Answer:
A. [H₃O⁺] = 0.900 M
B. pH = 0.0 to one decimal place
C. [H₃O⁺] = 0.620 M
D. pH = 0.21 to two decimal places
Explanation:
A. Equation for the complete dissociation of H₃PO₄ is given below:
H₃PO₄(s) + 3H₂O(l) -----> PO₄³⁻(aq) + 3H₃O⁺(aq)
From the equation of reaction, one mole of H₃PO₄ produces 3 moles of H₃O⁺
Therefore, [H₃O⁺] = 3 * 0.300M = 0.900 M
B. pH = -log[H₃O⁺]
pH = - log(0.900)
pH = -log (9 * 10⁻¹)
pH = 0.0 to one decimal place
C. Equation for the complete dissociation of H₂C₂O₄ is given below:
H₂C₂O₄(s) + 2H₂O(l) ----> C₂O₄⁻(aq) + 2H₃O⁺
From the equation of reaction, one mole of H₂C₂O₄ produces 3 moles of H₃O⁺
Therefore, [H₃O⁺] = 2 * 0.310 M = 0.620 M
D. pH = -log[H₃O⁺]
pH = -log(0.620)
pH = -log(0.62 * 10⁻¹)
pH = 0.21 to two decimal places
The concentration of [[tex]\rm H_3O^+[/tex]] has been 0.9 M, and the pH has been 0.045.
The polyprotic acid has been able to donate more than one proton in an acid-base reaction.
The balanced chemical reaction can be:
[tex]\rm H_3PO_4\;+\;3\;H_2O\;\rightarrow\;PO_4^3^-\;+\;3\;H_3O^+[/tex]
(a) According to the equation, 1 mole of [tex]\rm H_3PO_4[/tex] gives 3 moles of hydronium ions. The molarity has been defined as moles per liter. Assuming the volume of reaction to be 1 liter.
1 mole [tex]\rm H_3PO_4[/tex] = 1 M [tex]\rm H_3PO_4[/tex]
1 mole [tex]\rm H_3PO_4[/tex] = 3 moles [[tex]\rm H_3O^+[/tex]]
0.3 mole [tex]\rm H_3PO_4[/tex] = 3 [tex]\times[/tex] 0.3 moles [[tex]\rm H_3O^+[/tex]].
0.3 mole [tex]\rm H_3PO_4[/tex] = 0.9 moles [[tex]\rm H_3O^+[/tex]]
The concentration of [[tex]\rm H_3O^+[/tex]] has been 0.9 mole/L, or 0.9 M.
(b) pH of the solution can be defined as:
pH = -log [[tex]\rm H_3O^+[/tex]]
pH = -log (0.9)
pH = 0.045
The pH of the solution has been 0.045.
(c) The polyprotic acid have the balanced equation:
[tex]\rm H_2C_2O_4\;+\;2\;H_2O\;\rightarrow\;C_2O_4^-\;+\;2\;H_3O^+[/tex]
According to the equation, 1 M [tex]\rm H_2C_2O_4[/tex] gives 2 M [tex]\rm H_3O^+[/tex].
The concentration of hydronium ions from 0.310 M [tex]\rm H_2C_2O_4[/tex] has been:
1 M [tex]\rm H_2C_2O_4[/tex] = 3 M [tex]\rm H_3O^+[/tex]
0.310 M [tex]\rm H_2C_2O_4[/tex] = 2 [tex]\times[/tex] 0.310 moles [[tex]\rm H_3O^+[/tex]]
0.310 M [tex]\rm H_2C_2O_4[/tex] = 0.62 M [[tex]\rm H_3O^+[/tex]].
The [[tex]\rm H_3O^+[/tex]] concentration of the solution has been 0.62 M.
(d) pH of the solution can be defined as:
pH = -log [[tex]\rm H_3O^+[/tex]]
pH = -log (0.62)
pH = 0.20
The pH of the solution has been 0.20.
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Calculate the following quantity: volume of 1.58 M calcium chloride that must be diluted with water
to prepare 994 mL of a 6.20 x 10^-2 M chloride ion solution.
A 1.038 g sample of unknown containing C, H, and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis. Determine the empirical formula of the compound.
A) C3H3O
B) C6H6O
C) CH3O
D) C6H6O2
E) C2H6O2
Answer:
A. C3H3O
Explanation:
We have the following data:
m = mass of organic compound = 1.038g
Then mass of CO2 is 2.48g
Also mass of H2O is 0.510g
To calculate percentage of carbon = 12 x mass of CO2 x 100/44 x mass of organic compound
This gives us 65.1 percent
Formula to calculate percentage of H=
2 x mass of water x 100/18 x mass of organic compound.
= 2 x 0.510 x 100/18x 10038
This gives 5.4%
Percentage of Oxygen =100-(percentageof carbon +percentageof H)
= 100-(65.1+5.4)
= 100-70.5
= 29.5
We have to calculate emperical formula:
For C = 65.1
65.1/12
= 5.4
= 5.4/1.8
=3
For H=5.4
5.4/1
= 5.4
= 5.4/1.8
=3
For O = 29.5
= 29.5/16
= 1.8
= 1.8/1.8
=1
So the emperical formula of organic compound is given as
C3H3O1
= C3H3O
(The atomic weights of C, H, O are 12,1,16)
Washing machines use a large amount of water. A student suggested that old pairs of stained jeans which have to be washed more frequently should be replaced by new pairs of jeans to conserve water. Which of these statements best describes the suggestion made by the student? Question 9 options: It is not practical because an old pair of jeans needs less water to be washed than a new pair of jeans. It is practical because a huge amount of water can be conserved by this method. It is practical because it is easy to implement. It is not practical because it takes a huge amount of water to produce a new pair of jeans.
Answer:
C |||| It is not practical because it takes a huge amount of water to produce a new pair of jeans
Explanation:
If you're doing flvs then it's C.
Answer:
C!
Explanation:
i got it right on the test UwU
The reaction between iron(II) oxide and carbon monoxide produces iron and carbon dioxide. How many moles of iron can be obtained when 1.50 mol FeO reacts with an excess of CO ?
FeO+CO⟶Fe+CO2
Answer:
1.5 moles of Fe produced.
Explanation:
Given data:
Moles of FeO react = 1.50 mol
Moles of iron produced = ?
Solution:
Chemical equation:
FeO + CO → Fe + CO₂
Now we will compare the moles of ironoxide with iron.
FeO : Fe
1 : 1
1.5 : 1.5
Thus from 1.5 moles of FeO 1.5 moles of Fe are produced.
1.5 moles of Fe can be obtained when 1.50 mol of FeO reacts with an excess
of CO
Moles of FeO reacted = 1.50 mol
Moles of iron produced = ? mol
The chemical equation is given as
FeO + CO → Fe + CO₂
Comparisons of FeO and Fe show they are in the ratio 1 : 1
FeO : Fe
1.5 : 1.5
which translates to the number of moles being equal
Therefore, 1.5 moles of FeO 1.5 moles of Fe are produced.
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Which pair of elements would you expect to have similar properties?
Li and Fe
At and F
F and o
Ge and As
What factors affect the speed of a wave? Check all that apply. the amplitude of the wave the energy of the wave the temperature of the medium the type of wave the type of medium
Answer:
I believe its 1,2, and 5
Explanation:
C D E
temperature of medium
type of wave
type of medium
How many valence electrons are found in P3- ?
Answer:
5 valence elctrons
Explanation:
the outer most orbitals, 3s2 and 3p3 contains 5 electrons, thus valences electrons for P is 5
Blood takes about 1.55 s to pass through a 2.00 mm long capillary. If the diameter of the capillary is 5.00 μm and the pressure drop is 2.45 kPa, calculate the viscosity ???? of blood. Assume laminar flow.
Answer:
The viscosity [tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]
Explanation:
From the given information:
Time t = 1.55 s
The radius of capillary = 5.00 μm /2
The pressure drop ΔP = 2.45 kPa
The length of the capillary = 2.00 mm
∴
The viscosity of the blood flow can be calculated by using the formula:
[tex]\eta = \dfrac{r^2 \Delta P }{8Lv}[/tex]
where;
v = L/t
Then;
[tex]\eta = \dfrac{r^2 \Delta P }{8L(\dfrac{L}{t})}[/tex]
[tex]\eta = \dfrac{(\dfrac{5 \times 10^{-6} \ m}{2})^2(2.45 \times 10^3 \ Pa) }{8(2.0 \times 10^{-3} \ m ) (\dfrac{2.0 \times 10^{-3} \ m }{1.55 \ s })}[/tex]
[tex]\eta = 7.416 \times 10^{-4} \ Pa.s[/tex]
To (N.s/m²)
[tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]
The sun shines more directly near the equator, bringing more warmth there. In polar regions the sun shines at angles such that
they get little or no sunlight during the winter, causing colder temperatures. Predict how these differences in temperature create a
movement in the atmospheric gases and distribute heat energy from the sun across the planet.
A)
B)
As air in one region diffuses, it becomes less condensed than the
surrounding air and begins to rise and draws more air along.
As air in one region warms, it becomes less dense than the surrounding air
and begins to rise and draws more air in underneath.
As air in one region warms, it becomes less nebulous than the surrounding
air and begins to descend and draws more air in with it.
As air in one region cools, it becomes less compact than the surrounding
air and begins to accelerate and draws more air in supportively.
C)
D)
Answer:Because the Earth is round and not flat, the Sun's rays don't fall evenly on the land and oceans. The Sun shines more directly near the equator bringing these areas more warmth. However, the polar regions are at such an angle to the Sun that they get little or no sunlight during the winter, causing colder temperatures.
Explanation:
Determine the vapor pressure of a solution at 25°C that contains 76.6 g of glucose (C6H12O6 ) in 250.0 mL of water. The vapor pressure of pure water at 25°C is 23.8 torr
Answer:
[tex]23.093\ \text{torr}[/tex]
Explanation:
[tex]M_g[/tex] = Molar mass of glucose = 180.2 g/mol
[tex]M_w[/tex] = Molar mass of water = 18 g/mol
[tex]m_g[/tex] = Mass of glucose = 76.6 g
[tex]m_w[/tex] = Mass of water = [tex]250\times 1\ \text{g/mL}=250\text{g}[/tex]
[tex]P_0[/tex] = Vapor pressure of pure water at 25°C = 23.8 torr
The mole fraction of glucose is
[tex]x_g=\dfrac{\dfrac{m_g}{M_g}}{\dfrac{m_g}{M_g}+\dfrac{m_w}{M_w}}=\dfrac{\dfrac{76.6}{180.2}}{\dfrac{76.6}{180.2}+\dfrac{250}{18}}\\\Rightarrow x_g=0.0297[/tex]
Mole fraction of the solute would be
[tex]\dfrac{P_0-P}{P_0}=x_g\\\Rightarrow 0.0297=\dfrac{23.8-P}{23.8}\\\Rightarrow P=23.8-0.0297\times23.8\\\Rightarrow P=23.093\ \text{torr}[/tex]
The vapor pressure of the solution is [tex]23.093\ \text{torr}[/tex].
What is the energy of a wave if the frequency is 300. Hz
Answer:
[tex]E=1.98\times 10^{-31}\ J[/tex]
Explanation:
Given that,
The frequency of a wave, f = 300 Hz
We need to find the energy of a wave. The formula for the energy of a wave is given by :
E = hf,
Where h is Planck's constant
[tex]E=6.63\times 10^{-34}\times 300\\\\=1.98\times 10^{-31}\ J[/tex]
So, the energy of the wave is [tex]1.98\times 10^{-31}\ J[/tex].
a sample of lead had a mass of 150 g. The molar mass of lead is 207.19 g. How many moles of lead does the sample contain?
Answer:
Explanation:
no of moles=given mass/molar mass
no of moles=150 g/207.19
no of moles=0.72
We will use dimensional analysis to answer this question.
[tex]150 g * \frac{1 g}{207.19 mol} = 0.724 mol[/tex]
The answer is 0.724 mol.
Why can’t you ice skate on a lake when it is not frozen?
In the third century B.C., King Hieron of Syracuse asked the famous mathematician Archimedes to determine if his crown was made of pure gold. This was a puzzling problem for Archimedes-he knew how to measure the weight of the crown, but how could he measure the volume? Archimedes solved the problem when he got into his bath and noticed the water spilling over the sides of the tub. He realized that the volume of the displaced water must be equal to the volume of the object placed into the water. Archimedes was so excited by. his discovery that he jumped out of the bath and ran through the streets shouting "Eureka!" a. How can you tell if a crown is made of solid gold? b. Gold is one of the densest substances known, with a density of 19.3 g/mL. If the gold in the crown was mixed with a less-valuable metal like bronze or copper, how would that affect its density? c. What is the relationship between the object density, the liquid density, and the tendency of the object to float? d. From the experimental results obtained by you in the lab of the density of the liquid and the object, could the object float in that liquid? Explain.
Answer:
See explanation
Explanation:
a. I can conclusively tell if the crown was made of gold by measuring its density. First the mass of the crown is measured on a weighing balance. The crown is now put into a given volume of water and the volume of water displaced is accurately measured. The density of the crown is computed as mass/volume of fluid displaced. If the density of the crown is 19.3 g/mL, then it is made of solid gold.
b) When less valuable metals such as bronze or copper is mixed with gold in the crown, the density of the crown decreases and the crown becomes more brittle.
c) An object will float in a liquid when the density of the object is less than the density of the liquid. Hence the tendency of an object to float in a liquid depends on the density of the object and the density of the liquid.
d) Even though i do not know the results from your experiment but as regards the decision as to whether the object will float in the given liquid or not, reference must be made to the measured density of the object as well as the given density of the liquid. If the object is less dense (from values of density obtained from the experiment) than the liquid, then the object will float in the liquid and vice versa.
What is the mole fraction of water in a solution that contains 8.0 mol of ethanol (C2H5OH) and 1.6 mol of water?
Answer:
the mole fraction of water in a solution is 0.17
Explanation:
The computation of the mole fraction of water in a solution is shown below:
Given that
Ethanol be 8.0 mol
And, the water be 1.6 mol
Based on the above information, the mole fraction of water in a solution is
= Water ÷ (Water + ethanol)
= 1.6 mol ÷ (1.6 mol + 8.0 mol)
= 1.6 mol ÷ 9.6 mol
= 0.17
Hence, the mole fraction of water in a solution is 0.17
chlorine monobromide ionic or molecular
PLZ HELP PLZ
NO WRONG ANSWERS
Answer:
it is C
Explanation:
because Potassium iodide (KI) is an ionic compound which is made of the following ions: K+I−
Using the equations
2 C₆H₆ (l) + 15 O₂ (g) → 12 CO₂ (g) + 6 H₂O (g)∆H° = -6271 kJ/mol
2 H₂ (g) + O₂ (g) → 2 H₂O (g) ∆H° = -483.6 kJ/mol
C (s) + O₂ (g) → CO₂ (g) ∆H° = -393.5 kJ/mol
Determine the enthalpy (in kJ/mol) for the reaction
6 C (s) + 3 H₂ (g) → C₆H₆ (l).
The enthalpy : 49.1 kJ/mol
Further explanationThe change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
Based on the principle of Hess's Law, the change in enthalpy of a reaction will be the same even though it is through several stages or ways
Reaction
1. 2C₆H₆ (l) + 15 O₂ (g) → 12 CO₂ (g) + 6 H₂O (g)∆H° = -6271 kJ/mol
Reverse
12 CO₂ (g) + 6 H₂O (g) ⇒ 2C₆H₆ (l) + 15 O₂ (g) ∆H° = 6271 kJ/mol : 2
6CO₂ (g) + 3H₂O (g) ⇒ C₆H₆ (l) + 15/2 O₂ (g) ∆H° = 3135.5 kJ/mol
2. 2 H₂ (g) + O₂ (g) → 2 H₂O (g) ∆H° = -483.6 kJ/mol x 3/2
3H₂ (g) + 3/2O₂ (g) → 3H₂O (g) ∆H° = -725.4 kJ/mol
3. C (s) + O₂ (g) → CO₂ (g) ∆H° = -393.5 kJ/mol x 6
6C (s) + 6O₂ (g) → 6CO₂ (g) ∆H° = -2361 k/j/mol
-------------------------------------------------------------------------------------
6 C (s) + 3 H₂ (g) → C₆H₆ (l) ∆H° = 49.1 kJ/mol
We add up and the same compound that is on different sides we eliminate
Which of these statements best answers the question: What is art?
Answer:
You didn't provide any statements. If it is an option, art is a form of expression. Something created from imagination that expresses the thoughts and emotions of the artist.
The statement that best answers the question: What is art is that—Art is a form of visual language. Therefore, the correct option is A.
What is an art?Art is a diverse range of human activities and products that are created with the intention of expressing the imagination, emotions, or ideas, or to make a statement, in a visually appealing way.
Art can take many forms, including visual arts (such as painting, sculpture, and photography), performing arts (such as music, dance, and theater), and literary arts (such as poetry and prose).
It is typically seen as a form of communication and can be used to convey ideas, emotions, or political, social or cultural messages. It can also be used to simply evoke a response or emotion in the viewer, or to create a sense of beauty or aesthetic enjoyment. Therefore, the correct option is A.
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The question is incomplete, but most probably the complete question is,
Which of these statements best answers the question: What is art?
A. Art is a form of visual language.
B. Art is a form of written language.
C. Art is a form of spoken language.
D. Art is a form of dance language.