Answer:
Explanation:
The second one is quite simple. CH4 (methane) is the main component for natural gas. It is used to heat houses in many many areas. It it heats a house, it must give off heat. It is exothermic.
The first one is much less common and hard to reason. I think it is easier to see the reverse reaction
O2 ===> 2O
O2 is a fairly stable molecule. It takes energy to break the molecules apart. That makes this reaction endothermic.
So the reaction you are given is just the opposite. It must be exothermic.
2O ===> O2 must be exothermic.
How do endothermic processes differ from exothermic processes
Answer:
Endothermic proceses
Energy is absorbed by the substances from the environmentThe entalphy change is positiveThe energy of the products is higher than the energy of the reactants.The temperature of the surroundings decreases.More energy is required to break the chemical bonds of the reactants than what is released from the formation of the chemical bonds of the products.Exothermic proceses
Energy is released from the substances to the environmentThe entalphy change is negativeThe energy of the products is lower than the energy of the reactants.The temperature of the surroundings increase..More energy is released when the chemical bonds of the products are formed than what is needed to break the chemical bonds of the reactants.Explanation:
By definition an exothermic processes are those in which the system releases energy to the enviroment, while endothermic processes are those in which the system absorbs energy from the environment.
That change in energy is generally measured as heat.
Then an exothermic process releases heat and and endothermic process absorbs heat.
From that, as a first consequence, in an exothermic process the final substances (products in the case of a chemical reaction) ends with lower energy and lower temperature than the initial substances (reactants in the case of a chemical reaction).
The heat content of the substances is usually measured as enthalpy, then, for a chemical reaction you can write th is equation for the enthalpy change:
Δ H rxn = ΔH products - ΔH reactantsThus, for an exothermic reaction ΔH products < ΔH reactants ⇒ ΔH < 0, whilced for an endothermic reaction ΔH products > ΔH reactants ⇒ ΔH > 0.
The difference in energy between the products and the reactants is a result of the chemical potential energy of the substances, which is the energy stored in the chemical bonds. Then, in an endothermic reaction more energy is needed to break the chemical bonds of the reactants than what is released from the formation of the chemical bonds of the products. Of course the opposite is true: in an exothermic reaction, energy is released because it is required less energy for the formation of the new bonds of the products than what is needed to break the bonds of the reactants.
Which of the following is the trend down a period?
A. The number of complete electron shells increases by one.
B. The number of complete electron shells stays the same.
C. The number of outer shell electrons decreases by one.
D. None of these.
Answer:
B. The number of complete electron shells stays the same.
Explanation:
The periods on a periodic table consists of those elements that are arranged in the horizontal row in the periodic table.
Elements in the same period have the same number of electron shells and this corresponds to the period. This implies that elements of period 2 have two electron shells, those of period 3 have three shells and so on.
The number of Valence electrons of the elements on the same period increases progressively by one across the period from left to right.
A group is the vertical column to which elements are arranged on the periodic table. Elements in the same group have the same number of Valence electrons and the number of shell increases down a group.
When we go down a period, the number of shell stays the same.
What is the heat of reaction when sulfur dioxide reacts with oxygen to form sulfur trioxide? 2so2(g) + o2(g) → 2so3(g) (∆hf0 so2(g) = –298.8 kj/mol; ∆hf0 so3(g) = –395.7 kj/mol) –201.9 kj –492.6 kj –694.5 kj –193.8 kj?
Answer : The enthalpy change for this reaction is -193.8 kJ.
Solution :
The balanced chemical reaction is,
[tex]2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]
[tex]\Delta H=[(n_{SO_3}\times \Delta H_{SO_3})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{SO_2}\times \Delta H_{SO_2})][/tex]
where,
n = number of moles
[tex]\Delta H_{O_2}=0[/tex] (as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
[tex]\Delta H=[(2\times -395.7)]-[(1\times 0)+(2\times -298.8)][/tex]
[tex]Delta H=-193.8kJ[/tex]
Therefore, the enthalpy change for this reaction is, -193.8 KJ
Final answer:
The heat of reaction for the formation of sulfur trioxide from sulfur dioxide and oxygen, using the provided enthalpies of formation, is calculated to be -193.8 kJ.
Explanation:
The student has asked what the heat of reaction is when sulfur dioxide reacts with oxygen to form sulfur trioxide. The given balanced chemical equation is 2SO2(g) + O2(g) → 2SO3(g). The standard enthalpy of formation (ΔHf0) for SO2 is −298.8 kJ/mol, and for SO3 it's −395.7 kJ/mol.
Calculating the Heat of Reaction
To find the heat of reaction, we use the following formula:
ΔH = [∑ (ΔHf0 products)] - [∑ (ΔHf0 reactants)]
ΔH = [2 mol × (−395.7 kJ/mol SO3)] - [2 mol × (−298.8 kJ/mol SO2) + 1 mol × (0 kJ/mol O2)]
ΔH = [−2 × 395.7 kJ] - [−2 × 298.8 kJ]
ΔH = (−791.4 kJ) - (−597.6 kJ)
ΔH = −193.8 kJ
Therefore, the heat of reaction for the formation of sulfur trioxide from sulfur dioxide and oxygen is −193.8 kJ.
Jamie had $37 in his bank account on Sunday.
Answer:
where's the question... ?
is immoral an adaptation?
Answer:
Immoral means not moral and connotes evil or licentious behavior. Amoral, nonmoral, and unmoral, virtually synonymous although the first is by far the most common form, mean utterly lacking in morals (either good or bad), neither moral nor immoral.
so I would say no
Hope This Helps! Have A Nice Day!!
An oxide of niobium has a cubic unit cell in which there are oxide ions at the middle of each edge and niobum atoms at the center of each face. what is the empirical formula of this oxide?
Question 1:
1. One form of niobium oxide crystallizes in the unit cell shown above.
A. How many niobium atoms per unit cell? 3
B. How many oxygen atoms per unit cell? 3
C. What is the formula of niobium oxide? Nb2O5
Answer: A) 3 B) 3 C) Nb205
Question 2:
2. Quartz (left) and glass (right) are both forms of silicon dioxide. A piece of quartz breaks into a collection of smaller regular crystals with smooth faces. A piece of glass breaks into irregular shards. Use molecular structures to explain why the two solids break so differently. Select all that apply.
1. the bonding and geometry in quartz shows regular repeating patterns *
2. the bonding and geometry in quartz shows irregular repeating patterns
3. the bonding and geometry in glass shows irregular repeating patterns *
4. the atomic geometries of the two solids can explain why they break so differently *
5. the atomic geometries of the two solids cannot explain why they break so differently
6. the bonding and geometry in glass shows regular repeating patterns
Answer: 1,3,4
3. Solid silver adopts a face-centered cubic lattice. The metallic radius of a silver atom is 144 pm.
a. How many silver atoms occupy one unit cell of solid silver? 4
b. Calculate the length (in pm) of one side of the unit cell. 407
c. Calculate the volume (in m3) of one the unit cell. 6.74 x10^-29
d. What percentage (expressed to four significant figures) of the volume is empty? 25.95
Answer: a)4 b)407 c)6.74 x10^-29 d)25.95
4. Why hexane is insoluble in water? Select all that apply.
1. Water is polar solvent. *
2. Polar solvents dissolve both polar and non-polar compounds.
3. Polar solvents dissolve only polar compounds. *
4. Solubility does not depends on the polarity of the solvents and reagents.
5. Hexane is non-polar compound. *
Answer: 1,3,5
<3 goodluck
Final answer:
The empirical formula for the niobium oxide with oxide ions at the middle of each edge and niobium atoms at the center of each face is Nb2O, obtained by counting the ions per unit cell and adjusting for their location in the structure.
Explanation:
To determine the empirical formula of the niobium oxide, first, we need to consider how many ions are associated with each other in the cubic unit cell structure. A cubic unit cell with oxide ions at the middle of each edge and niobium atoms at the center of each face can be described as follows: each edge has 1/4 of an oxide ion since it is shared by 4 cubes, resulting in 1 oxide ion per unit cell (there are 12 edges, thus 12 x 1/4 = 3, but each oxygen is set twice, thus 3 / 2 = 1.5 but oxygen only gives 1 charge so we only take half). Each face-centered niobium contributes 1/2 of an atom to the unit cell since each face is shared between two unit cells, leading to 3 niobium atoms per unit cell (6 faces x 1/2 = 3). Therefore, for every 1 niobium atom, there is 0.5 of an oxide ion, and by multiplying both the niobium and oxide amounts by 2 to get whole numbers, we obtain the empirical formula Nb2O.
The coordination number of an ion in a crystalline structure is the number of counterions that surround it. In the niobium oxide unit cell described, the oxide ions are at the midpoint of each edge, and niobium atoms are at the center of each face. Without additional information, however, it is not possible to determine the exact coordination number, as this would depend on the 3D arrangement of the atoms within the cell.
a) What is the change in the cell voltage when the ion concentrations in the cathode half-cell are increased by a factor of 10?b) What is the change in the cell voltage when the ion concentrations in the anode half-cell are increased by a factor of 10?
Answer:
(a) The change in cell voltage is 0.05V
(b) The change in cell voltage is 0.03V
Explanation:
Redox reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases.
Further explanation:
The image taken in context is attached below.
The standard reduction potentials for iron and silver are:
[tex]E^o_{(Fe^{2+}/Fe)}=-0.44V\\E^o_{(Ag^{+}/Ag)}=+0.80V[/tex]
In the given cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode.
From the standard reduction potentials we conclude that, the substance having highest positive [tex]E^o[/tex] potential will always get reduced and will undergo reduction reaction.
So, silver will undergo reduction reaction will get reduced. Iron will undergo oxidation reaction and will get oxidized.
The given cell reactions are:
Oxidation half reaction (anode): [tex]Fe\rightarrow Fe^{2+}+2e^-[/tex]
Reduction half reaction (cathode): [tex]Ag^{+}+e^-\rightarrow Ag[/tex]
Thus, the anode and cathode will be [tex]E^o_{(Fe^{2+}/Fe)}[/tex]
and [tex]E^o_{(Ag^{+}/Ag)}[/tex] respectively.
The overall cell reaction will be,
[tex]2Ag^{+}+Fe\rightarrow Fe^{2+}+2Ag[/tex]
To calculate the [tex]E^o_{cell}[/tex] of the reaction, we use the equation:
[tex]E^o_{cell}=E^o_{cathode}-E^o_{anode}[/tex]
[tex]E^o=E^o_{(Ag^{+}/Ag)}-E^o_{(Fe^{2+}/Fe)}[/tex]
[tex]E^o=(+0.80V)-(-0.44V)=1.24V[/tex]
Now we have to calculate the cell potential.
Using Nernst equation :
[tex]E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Fe^{2+}]}{[Ag^{+}]^2}[/tex]
where,
n = number of electrons in oxidation-reduction reaction = 2
[tex]E_{cell}[/tex] = emf of the cell = ?
Now put all the given values in the above equation, we get:
[tex]E_{cell}=1.24-\frac{0.0592}{2}\log \frac{(1M)}{(1M)^2}[/tex]
[tex]E_{cell}=1.24V[/tex]
Thus, the emf of cell potential is 1.24 V
Part (a):
The ion concentrations in the cathode half-cell [tex](Ag^+/Ag)[/tex] are increased by a factor of 10 from 1 M to 10 M.
The emf of the cell potential will be,
Using Nernst equation :
[tex]E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Fe^{2+}]}{[Ag^{+}]^2}[/tex]
where,
n = number of electrons in oxidation-reduction reaction = 2
[tex]E_{cell}[/tex] = emf of the cell = ?
Now put all the given values in the above equation, we get:
[tex]E_{cell}=1.24-\frac{0.0592}{2}\log \frac{(1M)}{(10M)^2}[/tex]
[tex]E_{cell}=1.29V[/tex]
The change in cell voltage will be,
[tex]E_{cell}=1.29V-1.24V=0.05V[/tex]
Thus, the change in cell voltage is 0.05V
Part (b):
The ion concentrations in the anode half-cell [tex](Fe^{2+}/Fe)[/tex] are increased by a factor of 10 from 1 M to 10 M.
The emf of the cell potential will be,
Using Nernst equation :
[tex]E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Fe^{2+}]}{[Ag^{+}]^2}[/tex]
where,
n = number of electrons in oxidation-reduction reaction = 2
[tex]E_{cell}[/tex] = emf of the cell = ?
Now put all the given values in the above equation, we get:
[tex]E_{cell}=1.24-\frac{0.0592}{2}\log \frac{(10M)}{(1M)^2}[/tex]
[tex]E_{cell}=1.27V[/tex]
The change in cell voltage will be,
[tex]E_{cell}=1.27V-1.24V=0.03V[/tex]
Thus, the change in cell voltage is 0.03V
Learn more:
Spontaneity of reaction; https://brainly.com/question/13151873 (answer by Kobenhavn)
Standard reduction potential; https://brainly.com/question/8739272 (answer by RomeliaThurston)
Keywords:
Nernst equation, standard reduction potential, spontaneity of the reaction.
The change in the cell voltage when the ion concentrations in the ANODE half-cell are increased by a factor of 10 is 0.030 V
Further explanationWhat is the change in the cell voltage when the ion concentrations in the ANODE half-cell are increased by a factor of 10?
The Nernst equation
[tex]E=E^o - \frac{RT}{nF} lnQ[/tex]
E ∘ is the cell potential at standard conditions R is the ideal gas constant T is the absolute temperature n is the number of electrons transferred per mole of reaction F is the Faraday constant Q is the reaction quotient of the reactionThe given electrochemical cell has both aqueous species Fe 2 + and Ag + at 1 M concentration
If the anode concentration is increased by a factor of 10 , the cell potential will change by the correction term:
[tex]\Delta E = -\frac{RT}{nF} lnQ[/tex]
Now we determine the overall reaction
[tex]Fe(s) -> Fe^{2+}(aq)+2e [anode]\\2*(Ag^+(aq)+e -> Ag(s)) [cathode]\\Fe(s)+2Ag^+(aq)->Fe^{2+}(aq)+2Ag(s) [overall][/tex]
n=2 electrons were transferred
[tex]Q=\frac{[Fe^{2+}]}{[Ag^+]^2}[/tex]
The change in cell potential is
[tex]\Delta E = - \frac{RT}{nF} ln \frac{[Fe^{2+}]}{[Ag^+]^2}[/tex]
Note that [tex][Fe^{2+}]=10M[/tex] and assume that T=298.15 K
[tex]\Delta E = - \frac{8.314J/molK*298.15K}{2*96485C/mol} ln \frac{10M}{1M^2}\\\Delta E = -0.030 V[/tex]
Therefore the cell potential will decrease by 0.030 V
Learn moreLearn more about the cell voltage https://brainly.com/question/2326679Learn more about the ion concentrations https://brainly.com/question/11480712 Learn more about the cathode half-cell https://brainly.com/question/9502656Answer detailsGrade: 9
Subject: chemistry
Chapter: the ion concentrations
Keywords: the cell voltage, the ion concentrations, the cathode half-cell, the anode, factor
An atom of tin has an atomic number of 50 and a mass number of 119. How many protons, electrons, and neutrons are found in one neutral atom of tin?
Answer:
2.38
Explanation:
119 divided by 50 =2.38
i hope you get it right :)
A neutral atom of tin has 50 protons, 50 electrons, and 69 neutrons. The number of protons and electrons is determined by the atomic number, while the number of neutrons is calculated by subtracting the atomic number from the mass number.
Explanation:An atom of tin (Sn) is described by its atomic number and its mass number. The atomic number refers to the number of protons in the nucleus of the atom, and in a neutral atom, it also equals the number of electrons. Therefore, a neutral tin atom has 50 protons and 50 electrons.
The mass number, on the other hand, is the sum of protons and neutrons in the nucleus. Therefore, to find out the number of neutrons, you have to subtract the atomic number from the mass number: 119 - 50 = 69. So, a neutral tin atom has 69 neutrons.
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Given the following balanced chemical reaction, what volume of 3.0M H2SO4 is required to neutralize 60.0 mL of 0.5M NaOH? Be sure to include the formula and show your work for each step in the calculation.
Answer:
[tex]\boxed{\text{10 mL}}[/tex]
Explanation:
1. Write the balanced chemical equation.
[tex]\text{2NaOH} + \text{H$_{2}$SO$_{4}$} \longrightarrow\ \text{Na$_{2}$SO$_{4}$} + 2\text{H{$_{2}$O}}[/tex]
2. Calculate the moles of NaOH
[tex]\text{Moles of NaOH} =\text{60.0 mL NaOH} \times \dfrac{\text{0.5 mmol NaOH}}{\text{1 mL NaOH}} = \text{30 mmol NaOH}[/tex]
3. Calculate the moles of H₂SO₄.
[tex]\text{Moles of H$_{2}$SO$_{4}$}=\text{30 mmol NaOH} \times \dfrac{\text{1 mmol H$_{2}$SO$_{4}$} }{\text{2 mmol NaOH}} = \text{30 mmol H$_{2}$SO$_{4}$}[/tex]
4. Calculate the volume of H₂SO₄
[tex]c = \text{30 mmol H$_{2}$SO$_{4}$} \times \dfrac{\text{1 mL H$_{2}$SO$_{4}$}}{\text{3.0 mmol H$_{2}$SO$_{4}$}} = \text{10 mL H$_{2}$SO$_{4}$}[/tex]
The titration will require [tex]\textbf{10 mL}[/tex] H₂SO₄.
A solution of potassium hydroxide reacts completely with a solution of nitric acid. What solid mixture does it create?
Answer:
[tex]\boxed{\text{KNO}_{3}}[/tex]
Explanation:
The reaction is
KOH(aq) + HNO₃(aq) ⟶ KNO₃(aq) + H₂O(ℓ)
If you evaporate the water, the solid substance is the compound, potassium nitrate.
[tex]\boxed{\textbf{KNO}_{3}}[/tex]
KNO₃(aq) ⟶ KNO₃(s)
When 3.00 moles of hydrogen molecules and 1.50 moles of oxygen molecules react, they form 3.00 moles of water according to the reaction below. How many grams of water were formed? (Hint: This answer will have 3 SF.)
2H2+O2 ⇒ 2H2O
54.0 g
6.01 g
0.0185 g
0.167 g
Answer:
54.0 g.
Explanation:
From the given data and the balanced reaction:2H₂ + O₂ → 2H₂O.
When 3.00 moles of hydrogen molecules and 1.50 moles of oxygen molecules react, they form 3.00 moles of water according to the balanced reaction.
∴ The no. of grams in 3.0 moles of water = no. of moles x molar mass = (3.0 mol)(18.0 g/mol) = 54.0 g.
Answer:
A) 54.0 g
Explanation:
Hello! The answer to your question is 54.0 grams.
2H2 + O2 --> 2H2O
Because of that, we know our result will possess 3 significant figures.
The only sensible answer here (without the calculations) would be 54.0, due to the decimal placement. Hope this helps you!
Isotopes of the same element will have a different number of neutrons, but the same number of protons. TRUE OR FALSE
Answer:
TRUE
Explanation:
Which of the following pairs of elements is most likely to form an ionic compound?1.Nitrogen and sulfur? OR 2. Magnesium and Fluorine?
Answer:
Magnesium and fluorine.Explanation:
Ionic compounds are formed by the electrostatic attraction of cations and anions.
Cations, positive ions, are formed when atoms lose electrons, and anions, negative ions, are formed when atoms gain electrons.
When two different atoms have similar atraction for electrons (electronegativity) they will not donate to nor catch electrons from each other, so cations and anions will not be formed. Instead, the atoms would prefer to share electrons forming covalent bonds to complete their outermost shell (octet rule).
Then, in order to form ionic compounds the electronegativities have to substantially different. This situation does not happen between two nonmetal elements, which nitrogen and sulfur are. Then, you can predict safely that nitrogen and sulfur will not form an ionic compound.
Ionic compounds, then require the electronegativity difference that exist between some metals and nonmetals. Being magnesium an alkaline earth metal, its electronegativity is very low. On the other hand, fluorine the first element of the group 17, has the highest electronegativity of all the elements.Thus magnesium and fluorine will have enough electronegativity difference to justify the exchange of electrons, forming ions and, consequently, ionic compounds.
Magnesium and Fluorine are the elements most likely to form an ionic compound.
Explanation:The pair of elements most likely to form an ionic compound is Magnesium and Fluorine.
Binary ionic compounds are composed of a metal (cation) and a nonmetal (anion). Magnesium is a metal and has a low ionization potential, meaning it easily loses electrons. Fluorine is a nonmetal and has a high electron affinity, meaning it readily gains electrons. These properties make it highly likely for magnesium and fluorine to form an ionic compound, such as magnesium fluoride (MgF2).
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HURRY PLS!
What is the name of this molecule? (4 points) A straight chain of four carbons. There is a triple bond between the first and second carbons when counting from left to right.
4 carbon chain is butane. With a triple bond it is butane. Since the triple bond is on the first carbon it can be called 1-butyne, or but-1-yne.
what are polymers?
a.)small groups of carbon molecules
b.) long chains of halogen molecules
c.)long chain of carbon molecules
d.) small groups of halogen molecules
Answer:
c.)long chain of carbon molecules
Explanation:
A polymer is a long chain of many monomers joined together using chemical bonds.For example, a long chain of carbon molecules may form a polymes such as fatty acid.An example of polymers are proteins whose monomers are amino acids, cellulose and glycogen whose monomers are monosaccharides.Which of the following statements describes alkenes and alkynes but not alkanes?
A. They are aromatic compounds.
B. They are unsaturated.
C. They are saturated.
D. They are hydrocarbons.
Answer:
B. they are unsaturated
Explanation:
Alkanes are long chain hydrocarbons with only single bonds, alkenes are hydrocarbons with at least one double bond and alkynes are hydrocarbons with at least one triple bond.
Alkanes, alkenes and alkynes are all hydrocarbons. Therefore statement D. is incorrect
Hydrocarbons are compounds containing carbon and hydrogen only
Neither of the three are aromatic compounds therefore statement A is incorrect
Saturated hydrocarbons are where all the bonds between atoms are single bonds. Unsaturated hydrocarbonds are when at least there's one double or triple bond.
Alkanes are saturated and Alkynes and alkenes are unsaturated.
therefore statement B is correct where alkenes and alkynes are unsaturated but alkanes are not
Final answer:
Alkenes and alkynes are unsaturated hydrocarbons due to the presence of carbon-carbon double and triple bonds, respectively, differentiating them from saturated alkanes.
Explanation:
The correct answer to the question is B: Alkenes and alkynes are unsaturated hydrocarbons. This is because they contain double or triple carbon-carbon bonds respectively, which means they have fewer hydrogen atoms attached to the carbon backbone compared to alkanes, which contain only single bonds and are therefore saturated. The term saturated indicates that a molecule contains the maximum possible number of hydrogen atoms whereas unsaturated indicates the presence of double or triple bonds, which replace some hydrogen atoms.
Aromatic compounds, like benzene, are indeed hydrocarbons but they are classified by their distinct ring structure with delocalized electrons, which is not a characteristic of alkenes or alkynes. Alkenes and alkynes are not aromatic simply because they have unsaturated bonds. Alkanes are also hydrocarbons; however, they are saturated, which is a term not applicable to alkenes or alkynes.
What element is named after a country in the Western Hemisphere?
Americium is an element named for a country in the Western Hemisphere
The element named after a location in the Western Hemisphere is Tennessine (Ts), named after Tennessee. Naming elements after locations or scientists is customary in chemistry, pending approval by IUPAC.
Explanation:The element named after a country in the Western Hemisphere is Tennessine, with the symbol Ts. Element 117, Tennessine, was proposed by a team of scientists from Russia and the United States, named after the state of Tennessee. Naming elements after locations, particularly cities, regions, or countries is one of the traditions followed in the scientific community, as seen when a Russian research team named element 118 Oganesson, symbol Og, after the scientist Yuri Oganessian, who made significant contributions to the discovery of heavy elements.
Traditionally, it is typical for the discoverers of a new element to propose a name, which is then subject to approval by the International Union of Pure and Applied Chemistry (IUPAC) before it becomes official. Before getting their final names, elements may carry temporary systematic names based on Latin numbers corresponding to their atomic numbers.
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How many molecules are in 92 liters of butane at STP
please show work
2.5 x 10^24 molecules of C4H10
A sample of pure water is neutral because it contains
Answer:
A sample of pure water is neutral because it contains the same number of H₃O⁺ ions as OH⁻ ionsExplanation:
Neutral pH is 7.By definition pH = - log [H₃O⁺]Water ionizes according to this equilibrium equation:2 H₂O (l) ⇄ H₃O⁺ + OH⁺
So, the ionization (equlibrium) constant is:Kw = [H₃O⁺ ] [ OH⁺]
At 25°C, Kw = 1 × 10⁻¹⁴Hence: [H₃O⁺ ] [ OH⁺] = [H₃O⁺ ] ² = 1 × 10⁻¹⁴ ⇒ [H₃O⁺ ] = 10⁻⁷⇒ pH = - log (10⁻⁷) = 7If the change of enthalpy of this reaction when proceeding left to right is +14 kcal, which chemical equation is correct?
N2O4 2 NO2 + 14 kcal
N2O4 + 14 kcal 2 NO2
Answer:
N₂O₄ + 14 kcal ⇄ 2NO₂.
Explanation:
Since the sign of ΔH determines either the reaction is exothermic or endothermic:
+ve, the reaction is endothermic.
-ve, the reaction is exothermic.
∵ The change of enthalpy of this reaction when proceeding left to right is + 14 kcal (+ ve sign).
∴ The reaction is endothermic, the heat is a part of the reacatnts in the reaction.
So, the reaction is:
N₂O₄ + 14 kcal ⇄ 2NO₂.
Sports trainers treat sprains and soreness with ethyl bromide. it is manufactured by reacting ethylene with hydrogen bromide: h5sil9512 use bond energies to find the enthalpy change for this reaction
-59 kj/mol exothermic
The enthalpy change for the reaction of ethylene with hydrogen bromide to form ethyl bromide is -59 kJ/mol. This means that the reaction is exothermic, meaning that it releases heat.
What's the information aboutThe bond energies of the relevant bonds are as follows:
C-C bond energy: 347 kJ/mol
C-H bond energy: 413 kJ/mol
H-Br bond energy: 363 kJ/mol
C-Br bond energy: 276 kJ/mol
Reactants:
Ethylene: 2 C-H bonds + 1 C-C bond
Hydrogen bromide: 1 H-Br bond
Products:
Ethyl bromide: 3 C-H bonds + 1 C-C bond + 1 C-Br bond
Enthalpy change:
ΔH = Σ(bond energies broken in reactants) - Σ(bond energies formed in products)
ΔH = (2 × 413 kJ/mol + 1 × 347 kJ/mol) - (1 × 363 kJ/mol + 3 × 413 kJ/mol + 1 × 276 kJ/mol)
ΔH = -59 kJ/mol
Therefore, the enthalpy change for the reaction of ethylene with hydrogen bromide to form ethyl bromide is -59 kJ/mol. This means that the reaction is exothermic, meaning that it releases heat.
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This is a mixture that has different properties throughout.
Answer:
Heterogenous mixture is a mixture that has different properties throughout.
Explanation:
Mixture refers to substances that are not chemically mixed together, that is, they can easily be separated by physical methods. There are two major types of mixture; these are heterogeneous and homogeneous mixtures. Homogeneous mixtures refer to those mixtures that are uniform in composition. A good example of this is tap water. Heterogeneous mixture on the other hand refers to those mixtures, which are not uniform in composition. A good example of this is a mixture of water and sand.
What’s metamorphism
Explanation:
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Metamorphism is a process that involves rocks. This process occurs when they are subjected to a lot of pressure or temperatures.
This process also happens in the presence of fluids. There are different types of metamorphism such as dynamic, hydrothermal, shock, and others.
For the reaction cu2s(s) ⇌ 2cu+(aq) + s2- (aq), the equilibrium concentrations are as follows: [cu+ ] = 1.0 × 10-5 m, [s2-] = 1.0 × 10-2 m. the equilibrium constant is:
Answer:
1.0 x 10⁻¹².
Explanation:
For the reaction:Cu₂S(s) ⇌ 2Cu⁺(aq) + S²⁻(aq),
The equilibrium constant (Keq) = [Cu⁺]²[S²⁻]/[Cu₂S].
[Cu⁺] = 1.0 × 10⁻⁵ M, [S²⁻] = 1.0 × 10⁻² M.
[Cu₂S] = 1.0, since the concentration of solid is always can be considered = 1.0.
∴ Keq = [Cu⁺][S²⁻]/[Cu₂S] = (1.0 × 10⁻⁵)²(1.0 × 10⁻²)/(1.0) = 1.0 x 10⁻¹².
Answer: The equilibrium constant for the above reaction is [tex]1.0\times 10^{-12}[/tex]
Explanation:
Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as [tex]K_{c}[/tex]
For a general chemical reaction:
[tex]aA+bB\rightarrow cC+dD[/tex]
The expression for [tex]K_{c}[/tex] is written as:
[tex]K_{c}=\frac{[C]^c[D]^d}{[A]^a[B]^b}[/tex]
Concentration of solid and liquid substances in a chemical reaction is taken to be 1.
For the given chemical reaction:
[tex]Cu_2S(s)\rightarrow 2Cu^+(aq.)+S^{2-}(aq.)[/tex]
The expression for [tex]K_{c}[/tex] is written follows:
[tex]K_c=[Cu^+]^2\times [S^{2-}][/tex]
We are given:
[tex][Cu^+]=1.0\times 10^{-5}M[/tex]
[tex][S^{2-}]=1.0\times 10^{-2}M[/tex]
Putting values in above expression, we get:
[tex]K_c=(1.0\times 10^{-5})^2\times (1.0\times 10^{-2})\\\\K_c=1.0\times 10^{-12}[/tex]
Hence, the equilibrium constant for the above reaction is [tex]1.0\times 10^{-12}[/tex]
Thirty points to who ever can answer this problem
During an experiment, 104 grams of calcium carbonate reacted with an excess amount of hydrochloric acid. If the percent yield of the reaction was 80.15%, what was the actual amount of calcium chloride formed?
CaCO3 + HCl → CaCl2 + CO2 + H2O
A. 90.1 grams
B. 92.4 grams
C. 109.2 grams
D. 115.3 grams
Answer:
B. 92.4 g
Explanation:
the balanced equation for the reaction is as follows
CaCO₃ + 2HCl ---> CaCl₂ + CO₂ + H₂O
molar ratio of CaCO₃ to CaCl₂ is 1:1
number of CaCO₃ moles reacted - 104 g / 100 g/mol = 1.04 mol
therefore number of CaCl₂ moles reacted - 1.04 mol
mass of CaCl₂ expected to be formed = 1.04 mol x 111 g/mol = 115.44 g
percentage yield = actual yield / theoretical yield x 100 %
theoretical yield = 115.44 g
percentage yield = 80.15 %
substituting these values in the above equation
80.15 % = actual yield / 115.44 g x 100 %
actual yield = 92.5 g
therefore answer is B. 92.4 g
Why do northern lights appear in different colors? Because charged particles of solar wind ignite different gases in Earth's atmosphere Because electrons and protons of solar wind ignite the plasma present in the corona Because electrons and protons of solar wind cause severe proton showers on Earth Because charged particles of solar wind cause solar flares on the surface of the sun
Answer:
It is A. Because charged particles of solar wind ignite different gases in Earth's atmosphere.
Explanation:
Since the solar wind from the sun is too radioactive for humans (they would die), once the charged particles hit the earth's atmosphere it shows its color. Every element has its own color and once it hits the atmosphere it really starts to show.
Because charged particles of solar wind ignite different gases in Earth's atmosphere is the correct statement.
The northern lights, also known as the auroras, are a natural phenomenon that occurs when charged particles from the Sun's solar wind interact with the Earth's magnetosphere and atmosphere. The solar wind consists of charged particles, mainly electrons and protons, that are ejected from the Sun's outer atmosphere.
As these charged particles enter the Earth's magnetosphere, they follow the planet's magnetic field lines and are funneled toward the polar regions. When they reach the Earth's atmosphere, they collide with atoms and molecules, particularly those of oxygen and nitrogen.
These collisions excite the atoms and molecules, causing them to release energy in the form of light. The specific colors observed in the auroras depend on the type of gas present in the atmosphere and the altitude at which the collisions occur. Oxygen atoms emit green and red light, while nitrogen atoms produce blue and purple light.
Learn more about northern lights, here:
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In a(n) _____ reaction, the products are at a higher energy level than are the reactants.
Select one:
a. endothermic
b. activation
c. exothermic
d. catalytic
Answer:
In an endothermic reaction, the products are at a higher energy level than are the reactants.
Explanation:
Endothermic reaction has positive ΔH.ΔH = E products - E reactants.
So, for endothermic reactions, the products are at a higher energy level than are the reactants.
Kindly see the attached image.
So, the right choice is: a. endothermic.Which of the following would increase the rate of a chemical reaction between hydrochloric acid (HCl) and solid zinc metal (Zn)? A. Decreasing the amount of Zn B. Performing the reaction at a lower temperature C. Pulverizing the zinc metal into a fine powder D. Decreasing the concentration of HCl
Answer:
C. Pulverizing the zinc metal into a fine powder
Explanation:
Pulverizing the zinc metal into a fine powder would increase the rate of chemical reaction between hydrochloric acid and zinc metal.This can be explained by the fact that pulverizing the zinc metal into fine powder will increase the surface area or the area of contact with the other reactant, HCl, thus making the reaction rate increase.Increase in surface area of the reactant Zinc increases the frequency of collision between the reactant particles, and in turn increasing the rate of reaction.Answer: C. Pulverizing the zinc metal into a fine powder
Explanation:
What is the first quantum number of a 1s2 electron in phosphorus, 1s22s22p63s23p3?
Answer: Im pretty sure n=1 as thats the first one indicated.
Explanation:
Answer:
n=1
Explanation:
What is the molarity of a solution containing 5 moles of HCl in 2.5 L of solution? Be sure to include the formula for calculating molarity and show your work for each step in the calculation.
Answer:
[tex]\boxed{\text{2 mol/L}}[/tex]
Step-by-step explanation:
[tex]c = \dfrac{ \text{moles} }{ \text{litres}}\\\\c = \dfrac{n }{V }[/tex]
Data:
n = 5 mol
V = 2.5 L
Calculation:
[tex]c = \dfrac{ \text{5 mol} }{\text{2.5 L}} = \text{2 mol/L}[/tex]
The molar concentration of the solution is [tex]\boxed{\textbf{2 mol/L}}[/tex].