Answer:
C. 70%
Explanation:
Atomic Mass of the silicon = 28 g.
Atomic mass of the Carbon = 12 g.
Total mass of the Silicon Carbide = 28 + 12
= 40 g.
Now, Using the formula.
% Composition = Mass of the silicon/Total mass of the compound × 100 %
= 28/40 × 100 %
= 70 %
Hence, % composition of the silicon in SiC is 70%
Can someone explain what each of the answer choices will do to the equilibrium? Shiftwise?
Answer:
[tex]\boxed{\text{(B)}}[/tex]
Explanation:
CaF₂(s) ⇌ Ca²⁺(aq) + F⁻(aq); ΔH > 0
According to Le Châtelier's Principle, when a stress is applied to a system at equilibrium, the system will respond in a way that tends to relieve the stress.
Let's consider each of the stresses in turn.
(A) Evaporating some of the water
The concentrations of the ions will increase, so calcium fluoride will precipitate out to remove the stress (the Ca²⁺ and F⁻ ions). The position of equilibrium does not shift, and [Ca²⁺] stays the same.
(B) Adding HNO₃
HF is a weak acid, so F⁻ is a relatively strong base. The added HNO₃ will convert the F⁻ ions to HF, removing them from solution. More CaF₂ will dissolve to replace the F⁻ ions, and this will add more Ca²⁺ ions as well. The position of equilibrium will shift to the right, and [Ca²⁺] will increase.
(C) Adding NaNO₃(aq)
There is no common ion, so NaNO₃ will have no effect. The added water will dilute the solution and decrease the concentrations of the ions. However, more CaF₂ will dissolve to increase the concentrations. The position of equilibrium does not shift, and [Ca²⁺] stays the same.
(D) Adding NaF
This is the common ion effect. F⁻ is the common ion. The added NaF will dissolve, increasing the concentration of F⁻ ions. More CaF₂ will precipitate to remove the added F⁻ ions, but it removes Ca²⁺ ions at the same time. The position of equilibrium shifts to the left, and [Ca²⁺] decreases.
In terms of bonds, what would the molecule C₆H₁₂ be classified as?
Alkyne
Alkane
Alkene
Inorganic compound
Answer:
Alkene
Explanation:
What element marks the boundary between using fusion and fission to release energy?
Answer:
matter
Explanation:
Iron marks the boundary between fusion and fission for energy release. Lighter elements than iron release energy through fusion, while heavier elements release energy through fission. Iron has the highest binding energy per nucleon, making it a turning point on the energy-mass curve.
The element that marks the boundary between using fusion and fission to release energy is iron (Fe). In the context of nuclear reactions, fusion occurs when two light nuclei combine to form a heavier nucleus, releasing energy because the combined nucleus has a higher binding energy per nucleon.
In contrast, fission is the process of splitting a heavy nucleus into smaller nuclei, releasing energy because the products have a higher binding energy per nucleon than the original heavy nucleus.
Iron possesses the highest binding energy per nucleon, which is why it is an energy-increasing process to fuse nuclei lighter than iron. For elements heavier than iron, fission becomes an energy-releasing process. Thus, iron is a unique marker in the periodic table where the more energy-efficient method of releasing nuclear energy switches from fusion to fission.
Fusion is responsible for powering stars and for the creation of elements in the universe through a process known as nucleosynthesis. Furthermore, while fission has been utilized in nuclear weapons and reactors, fusion promises to release far more energy per reaction, making it an attractive but technically challenging energy source. On an energy-mass curve, nuclei to the left of iron release energy through fusion while those to the right produce energy through fission.
A 100-w light bulb is about 16% efficient. how many joules of heat energy are siddipated by the bulb each second
Answer:
84 Joules are wasted per second.
Explanation:
An efficiency of 16% means 84% is wasted as heat energy.
Therefore;
For a 100W bulb;
Heat wasted = 84/100 × 100 W
= 84 W
Therefore;
84 W or 84 joules are wasted as heat per second
Choose the products that complete the reaction. The chemical equations may not be balanced.
The products that complete the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) are water (H₂O) and sodium chloride (NaCl).
Explanation:In the given chemical equation, HCl + NaOH, hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) to produce water (H₂O) and sodium chloride (NaCl). This reaction is a classic example of an acid-base neutralization reaction. The hydrogen ion (H⁺) from the acid combines with the hydroxide ion (OH⁻) from the base to form water, and the remaining ions, sodium (Na⁺) from the base and chloride (Cl⁻) from the acid, combine to form sodium chloride.
The balanced chemical equation for this reaction is:
HCl + NaOH → H₂O + NaCl
This equation illustrates the conservation of mass, with the same number of atoms of each element on both sides of the equation. The coefficients in the balanced equation indicate the stoichiometry of the reaction, showing the molar ratios between the reactants and products. In this case, one mole of hydrochloric acid reacts with one mole of sodium hydroxide to produce one mole of water and one mole of sodium chloride.
It's important to note that in a balanced chemical equation, the number of atoms of each element must be the same on both sides. This ensures that the law of conservation of mass is satisfied, meaning that no atoms are created or destroyed during the chemical reaction. In the case of the reaction between HCl and NaOH, the balanced equation accurately represents the chemical changes that occur during the neutralization process.
Full Question:Choose the products that complete the reaction. The chemical equations may not be balanced. HCL + NaOH →?
The main reason why H2CO has a higher vapor pressure at a given temperature when compared to CH3OH is that H2CO
Answer:
Cannot form hydrogen bonds to its neighbours.
Explanation:
The strongest intermolecular forces in H₂CO are dipole-dipole attractions between the polar C=O bonds in nearby molecules.
The strongest intermolecular forces in CH₃OH are strong hydrogen bonding attractions between the O-H group in one molecule and the O atom in a nearby molecule.
Since H₂CO molecules have weaker intermolecular forces than methanol, more of them can escape from the liquid to the vapour phase.
Thus, CH₂O has a higher vapour pressure than methanol.
Formaldehyde (H2CO) has a higher vapor pressure than methanol (CH3OH) due to weaker intermolecular forces, as methanol can form stronger hydrogen bonds which formaldehyde cannot, leading to a lower vapor pressure for methanol.
Explanation:The main reason why H2CO (formaldehyde) has a higher vapor pressure at a given temperature compared to CH3OH (methanol) is because of the different types of intermolecular forces (IMFs) present in each compound. Methanol can form hydrogen bonds due to its -OH group, which are much stronger than the dipole-dipole interactions and London dispersion forces present in formaldehyde.
Despite methanol and formaldehyde having similar molar masses, the stronger hydrogen bonding in methanol means that more energy is needed to escape from the liquid phase, resulting in a lower vapor pressure for methanol compared to formaldehyde.
What names are listed on the vietnam veterans memorial monument?
There are the names of more than 58,000 men and women who gave their lives or remain missing.
What is the name of the opposite stereoisomer of the molecule shown below?
A. trans-2-pentene
B. 2-ethylpropane
C. cis-2-pentene
D. 1-propene
Answer:
the answer is d hope this helps
and dont forget to mark me as brainliest
Explanation:
Trans-2-pentene is the name of the opposite stereoisomer of the molecule shown in the figure. Hence, option A is correct.
What is a stereoisomer?Stereoisomers are isomers that have the same composition but that differ in the orientation of those parts in space.
When two or more compounds differ in the position of substituent atom or functional group on the carbon skeleton, they are called position isomers and this phenomenon is termed as position isomerism.
Pent-2-ene and pent-l-ene are position isomers because differ in the position of double bond.
The two stereoisomers are (Z)-pent-2-ene and (E)-pent-2-ene.
Hence, option A is correct.
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Would a solution with a pOH of 11 be acidic or basic?
Answer:
Its acidic.. With pH=3
Explanation:
pH + pOH =14
Let pH be x then
x + 11 = 14
x = 3
pH less than 7, solution is acidic.
The solution with a pOH of 11 will be acidic in nature.
Explanation:When the aqueous solution is dissociated based upon the ions released by them it is categorized as acids or bases. When the solution gives out [tex]H^+[/tex] ion it is called as acid, whereas if it gives out [tex]OH^-[/tex] ions it is called as bases.
The concentration of [tex]H^+[/tex] ions is represented by pH, whereas the concentration of [tex]OH^-[/tex] ion is represented by pOH. In pOH scale value seven refers to neutral, whereas value below seven shows that the substance is basic whereas the value above seven indicates the substance as acidic.
Thus, it can be inferred that the solution with a pOH of 11 will be acidic in nature.
Identify which one is the oxidizing agent in this reaction:
2 KNO3 (s) → 2 KNO2 (s) + O2 (g)
Show ALL work.
Answer:
Nitrogen atom
Explanation:
Oxidation and reduction in a equation can be shown using oxidation numbers.Oxidation number of Oxygen in KNO3 is -2 while in O2 is 0; this indicates reduction.Oxidation number of Nitrogen (N) in KNO3 is + 5, while in KNO2 is +3 , this indicates oxidation.Hence;
Nitrogen has undergone reduction while oxygen has undergone oxidation and therefore, nitrogen is the oxidizing agent and oxygen is the reducing agent.In terms of bonds, what would the molecule C₃H₆ be classified as?
Inorganic compound
Alkene
Alkyne
Alkane
The molecule C3H6 is classified as a Alkene.
The answer is alkene
in which of the following cases will there be precipitation
A)QB)Q=Ksp
C)Q<D)Q>Ksp
Answer:
I think D
Explanation:
Q > Ksp, there are more ions in solution than are necessary for saturation. This is a supersaturated solution (i.e There is a tendency for the extra solute to precipitate).
Words to equation and balancing
Answer:
Pb(NO₃)₂ ₍aq₎ + 2 KI ₍aq₎ ------------> PbI₂ ₍s₎ + 2 KNO₃ ₍aq₎
Explanation:
Chemical Equation:
lead(II) nitrate: Pb(NO₃)₂
potassium iodide: KI
lead(II) iodide: PbI₂
Potassium nitrate: KNO₃
Pb(NO₃)₂ ₍aq₎ + KI ₍aq₎ ------------> PbI₂ ₍s₎ + KNO₃ ₍aq₎
Balancing the equation:
For balancing the equation all atoms of the elements on both sides of equation i.e reactants and products are equal.
So balancing the above equation we get:
Pb(NO₃)₂ ₍aq₎ + 2 KI ₍aq₎ ------------> PbI₂ ₍s₎ + 2 KNO₃ ₍aq₎
Identify the base and conjugate acid pair in the following equation: HF + H 2 O >
H 3 O + + F -
Answer:
Here's what I get.
Explanation:
An acid is a proton donor; a base is a proton acceptor.
Thus, HF is the acid and H₂O is the base.
The conjugate base is what's left after the acid has given up its proton.
The conjugate acid is what's formed when the base has accepted a proton.
HF/F⁻ make one conjugate acid/base pair, and H₂O/H₃O⁺ are the other conjugate acid/base pair.
[tex]\rm \underbrace{\hbox{HF}}_{\hbox{acid}} + \underbrace{\hbox{H_{2}\rm O}}_{\hbox{base}} \rightleftharpoons \underbrace{\hbox{H_{3}\rm O^{+}}}_{\hbox{conj. acid}} +\underbrace{\hbox{F^{-}}}_{\hbox{conj. base}}[/tex]
A tank has a total pressure of 285 kPa and contains Hydrogen, Oxygen, Carbon dioxide, and Neon. If Neon has a partial pressure of 14 kPa, carbon dioxide is 13 kPa, and Oxygen has a partial pressure of 157 kPa, what is the partial pressure of Hydrogen?
Answer:
Lets the total pressure is Pt and the individual gases are designated as pH2, pCO2, pNe, pO2.
Pt = pCO2+ pNe+pO2+ pH2
285KPa = 13 KPa+ 14 KPa + 157 KPa +pH2
Now add the partial pressure of CO2, Ne and O2 which is equal to 184 KPa.
285 KPa = 184 KPa + pH2
Now subtract the individual pressure of each gas from thje total pressure.
285 KPa - 184 KPa = pH2
101 KPa = pH2
The partial pressure of hydrogen is 101 KPa.
The differences between two molecules include the type of sugar that forms a section of the molecules and the identity of one of the four nitrogenous bases that make up another section of the molecules. These two molecules are —
The answer is nucleic acids
Which type of reaction happens when a base is mixed with an acid
nutrition reaction or saline reaction because these reactions generate salts , such as:
HCl + NaOH==>NaCl + H2O
How many functional groups are in the compound?
Four
Two
Three
One
Answer:
Two functional groups
Explanation:
We have the carboxylic group and the amine group.
The COOH group to the left is the alkanoic acid/carboxylic acid group..
The NH₂ to the right is the amino functional group.
PLEASE HELP WILL MARK BRAINLIEST!!!Which balanced equation represents an oxidation-reduction reaction? (explain)
(1) Ba(NO3)2 + Na2SO4 ==> BaSO4 + 2NaNO3
(2) Fe(s) + S(s) ==> FeS(s)
(3) H3PO4 + 3KOH==> K3PO4 + 3H2O
(4) NH3(g) + HCl(g)==> NH4Cl(s)
Answer:
(2) Fe(s) + S(s) → FeS(s)
Explanation:
The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).An oxidizing agent, or oxidant, gains electrons and is reduced in a chemical reaction. Also known as the electron acceptor, the oxidizing agent is normally in one of its higher possible oxidation states because it will gain electrons and be reduced.A reducing agent (also called a reductant or reducer) is an element (such as calcium) or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction.The only reaction that include oxidant and reductant:(2) Fe(s) + S(s) → FeS(s).
Fe is oxidized to Fe²⁺ in (FeS) (loses 2 electrons). "reducing agent".
S is reduced to S²⁻ in (FeS) (gains 2 electrons). "oxidizing agent".
The first reaction: (1) Ba(NO3)2 + Na2SO4 ==> BaSO4 + 2NaNO3
is replacement reaction.
The third reaction: (3) H3PO4 + 3KOH==> K3PO4 + 3H2O
is acid-base reaction.
The fourth reaction: (4) NH3(g) + HCl(g)==> NH4Cl(s)
is synthesis reaction.
The balanced chemical equation which represents a redox reaction is:[tex]Fe_(_s_)+S_(_s_) \rightarrow FeS_(_s_)[/tex] as it includes an oxidant and a reductant. The correct option is 3.
Redox reactions comprise of two parts a reduced part and an oxidized part, which occur simultaneously . The part which is reduced gain electrons and hence there is a increase in oxidation state of the species.
While, the part which is oxidized looses electrons and hence there is a decrease in oxidation state of the species.During redox reactions, there is no net change in the number of electrons . Electrons which are given off in oxidation are used up in reduction.
The ion or molecule which accepts electrons is called as oxidizing agent while the ion or molecule which donates electrons is called as a reducing agent.The only reaction which is an oxidation-reduction reaction is that of iron and sulfur where iron is oxidized and sulfur is reduced.
Thus, the correct option is 3.
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What is quantum physics
It has to do with time travel
Final answer:
Quantum physics is a branch of physics focusing on the behavior of matter and energy at atomic and subatomic levels, defining energy, momentum, and other quantities in discrete values. It introduces the wave-particle duality of quantum particles and quantization, where energy is exchanged in fixed quanta.
Explanation:
Introduction to Quantum Physics:
Quantum physics, also known as quantum mechanics, is a fundamental theory in physics that explains the behavior of matter and energy at the atomic and subatomic levels. Unlike classical physics, which adequately describes the motion of macroscopic objects, quantum physics is essential for understanding phenomena that occur at extremely small scales where wave-particle duality and quantization become significant. The quantization aspect of quantum mechanics means that energy, momentum, and other quantities of a system can only take on discrete values.
It's this branch of physics that reveals the dual nature of particles, such as electrons, acting both as particles and as waves. This duality is one of the many counterintuitive aspects of quantum mechanics that do not align with everyday experiences and observations. In the world of quantum mechanics, particles gain or lose energy in fixed amounts called quanta. The field also delves into the strange properties and behaviors of quantum entities, predicting probabilities rather than certainties.
Understanding quantum mechanics is crucial for a variety of applications, including the study of atoms, construction of lasers, and the development of quantum computers. It's a field that continues to challenge our perceptions of reality and pushes the boundaries of what we consider possible in the physical world.
Adding a catalyst to a reaction would increase which quantity?
A. grams of product produced in an hour
B. grams of product at the end of the reaction
C. concentration of product at the end of the reaction
D. concentration of reactants at the end of the reaction
Answer:
A. grams of product produced in an hour
Explanation:
Catalysts are substances that speed up chemical reactions. They do so by lowering the activation energy of the reactants, minimum energy required to start a chemical reaction.Therefore, catalysts speed up the rate of reaction by lowering the activation energy of the reactants. This means catalysts will have no effect on the concentration of products or reactants and therefore the yield remains the same.Now moles: _(1, 2, or 3)_moles of H2 + _(1, 2, or 3)_ moles of O2 → _(1, 2, or 3)_moles of H2O
Answer:
2H₂ + O₂ → 2H₂O.
Explanation:
For the reaction of water formation:2H₂ + O₂ → 2H₂O.
It should apply the the law of conservation of mass that the no. of reactants atoms is equal to the no. of products atoms.So, every 2.0 moles of H₂ react with 1.0 mole of O₂ to produce 2.0 moles of H₂O.
The balanced equation of the reaction is:
[tex]\underline{2}H_2\ +\ \underline{1}O_2\ \rightarrow \underline{2}H_2O\\[/tex]
How to balance the equation given?A balanced equation must have equal numbers of moles of the various element on both sides of the equation.
Now, lets us analyze the given equation. This is show below:
[tex]\_H_2\ +\ \_O_2\ \rightarrow \_H_2O\\[/tex]
Reactants:
H = 2O = 2Products:
H = 2O = 1From the above, it is obviously clear that the equation is not balanced.
Therefore, the equation can be balanced by writing 2 before hydrogen gas, H₂ and 2 before water, H₂O as shown below:
[tex]\underline{2}H_2\ +\ \underline{1}O_2\ \rightarrow \underline{2}H_2O\\[/tex]
Now, we can say that the equation is balanced.
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The first law of thermodynamics is a restatement of the
the law of thermodyanamic is the restatement of the law of conservation of energy
For which of the following can a relative age be determined? Select all that apply.
A.
fossil
B.
rock layer
C.
volcanic eruption
D.
folded rock layers
E.
faulted rock layers
Answer: A. fossil
B. rock layer
Explanation:
Relative aging or dating can be define as the technique for determination of the age of the rock and fossil. It is a method of determining the chronological order of the past events by comparing the stratigraphic column of rocks and sediments with each other. This method can only give relative age of one object in comparison with the other but does not give the absolute date.
Carbon disulfide burns with oxygen to form carbon dioxide and sulfur dioxide in the following manner: CS2 + 3O2 → CO2 + 2SO2
What is the volume of sulfur dioxide (SO2 gas), formed when 2 moles of carbon disulfide (CS2) are burned? The reaction is taking place at STP.
5.6 L
22.4 L
89.6 L
44.8 L
Answer:
89.6 L.
Explanation:
For the balanced reaction:CS₂ + 3O₂ → CO₂ + 2SO₂.
It is clear that 1.0 mole of CS₂ with 3.0 moles of O₂ to produce 1.0 mole of CO₂ and 2.0 moles of SO₂.Using cross multiplication:
1.0 mole of CS₂ produces → 2.0 moles of SO₂.
2.0 mole of CS₂ produces → ??? moles of SO₂.
∴ The no. of moles of SO₂ produced = (2.0 mol)(2.0 mol)/(1.0 mol) = 4.0 mol.
It is known that 1.0 mole of any gas at STP occupies 22.4 L.∴ 4.0 moles of SO₂ occupy = (4.0)(22.4 L) = 89.6 L.
Answer:
89.6 L.
Explanation:
A population of gray foxes lives in a forest ecosystem. These foxes prey mostly on a large population of mice. If a fatal disease infects the mouse population, which of these is most likely to happen to the fox population through time?
Answer and Explanation:
Answer: C. An increase in food availability increases the birth rate in the population.
Explanation:
The conveying limit of a biological system can be characterized as the greatest size of a populace of an animal types an environment can uphold based on accessibility of assets, for example, food, water, living space and different necessities.
An increase in food availability increases the birth rate in the population
is the right choice in light of the fact that to build the populace till the conveying limit there should be excess stock of food ought to be accessible to the populace which can uphold in expansion in birth rate so the populace can achieve a level at the conveying limit.
In which set of elements would all members be expected to have very similar chemical properties?A) O, S, SeB) S, Se, SiC) N, O, FD) Ne, Na, MgE) Na, Mg, K
Answer:
A. O, S, Se
Explanation:
If you look up Oxygen (O), Sulfur (S) and Selenium (Se) in the periodic table, you will see that these three fall under the same column. In the periodic table, elements are arranged in rows and columns. Columns are called groups. The elements that fall under the same group share similar chemical properties.
The elements given above are all in Group VIA or group 16.
Rutherford's model of the atom was similar to Bohr's model because they both thought that:
electrons were located in the nucleus of the atom
the nucleus of the atom was centrally located in the atom and was positively charged
the nucleus was negatively charged and that the electrons were positively charged
electrons were too small in size to affect the properties of atoms
Answer:
the nucleus of the atom was centrally located i n the atom and was positively charged
Explanation:t
Answer:
the nucleus of the atom was centrally located in the atom and was positively charged
Explanation:
Electrons orbit outside the nucleus. Option A is incorrect.
Nucleus is positive in charge and is located at the center of the atom. Option B is correct.
The nucleus is positively charged and that the electrons are negatively charged. Option C is incorrect.
Electrons do affect the properties of atoms. Option D is incorrect.
The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: c2h4 (g) + 3o2 (g) → 2co2 (g) + 2h2o (l) the value of δs° for this reaction is ________ j/k⋅mol.
Answer:
[tex]\boxed{-267.5}[/tex]
Explanation:
You can calculate the entropy change of a reaction by using the standard molar entropies of reactants and products.
The formula is
[tex]\Delta_{r} S^{\circ} = \sum_n {nS_{\text{products}}^{\circ} - \sum_{m} {mS_{\text{reactants}}^{\circ}}}[/tex]
The equation for the reaction is
C₂H₄(g) + 3O₂(g) ⟶ 2CO₂(g) + 2H₂O(ℓ)
ΔS°/J·K⁻¹mol⁻¹ 219.5 205.0 213.6 69.9
[tex]\Delta_{r} S^{\circ} = (2\times213.6 + 2\times69.9) - (1\times219.5 + 3\times205.0)\\\\= 567.0 - 834.5 = \boxed{-267.5 \text{ J}\cdot\text{K}^{-1} \text{mol}^{-1}}[/tex]
The value of ΔS for the given reaction is –267.5 J/Kmol
The value of ΔS for the reaction given above can be calculated by using the standard entropies of the reactants and products.
The standard entropies for each compounds are given below:
ΔS for C₂H₄ = 219.5 J/Kmol ΔS for O₂ = 205.0 J/Kmol ΔS for CO₂ = 213.6 J/Kmol ΔS for H₂O = 69.9 J/KmolThus, we can obtain the change in the entropy, ΔS for the reaction as illustrated below:
C₂H₄ + 3O₂ —> 2CO₂ + 2H₂O
Change in entropy = entropy of product – entropy of reactant
ΔS = ΔSₚ – ΔSᵣ
ΔS = [(2×213.6) + (2×69.9)] – [(1×219.5) + (3×205)]
ΔS = [427.2 + 139.8] – [219.5 + 615]
ΔS = 567 – 834.5
ΔS = –267.5 J/Kmol
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This is a temperature where the vapor pressure of a liquid equals the atmospheric pressure.
Answer:
The answer is boiling point.
Explanation:
The boiling point of a substance refers to the temperature at which the vapour pressure of a liquid equals the atmospheric pressure; at this point the liquid will boil. Different liquids have different boiling points that are unique to them. This makes it possible for scientists to use boiling points as one of the criteria by which a liquid substance can be identified. At boiling point, the chemical bonds that are holding liquid particles together are destroyed and the liquid turn to gas.