Answer:
The correct option is -286 kJ
Explanation:
The given parameters are
C(s) + O₂(g) → CO₂(g) ΔHf = -394 kJ
H₂(g) + 12O₂(g)→H₂O ΔHf = -242 kJ
2C(s) + 3H₂(g)→C₂H₆(g) ΔH = -84 kJ
Te given equation is C₂H₆(g) + 7/2O₂(g) →2CO₂(g) + 3H₂O(l)
The heat of formation or enthalpy of combustion = Heat of formation of the products - Heat of formation of the reactants
The enthalpy of combustion of the reaction = 2*(-394) + 3*(-242)- ((-84)+7/2*0)) = -1,430 kJ
Given that the reaction consists of one mole of C₂H₆(g), we have;
The enthalpy of combustion of one mole of C₂H₆(g) = -1,430 kJ
Therefore, the enthalpy of combustion of 0.2 mole of C₂H₆(g) = -1,430 kJ × 0.2 = -286 kJ
The correct option = -286 kJ.
Answer:
Positive 1,430
Explanation:
Hi does anyone know how to do question 4?
Please show working out thanks.
answer:
a)1.274 g b) 0.013 mole
Explanation:
a) Mass of 1 mol of CuSo4. 5H20=
[tex]63 + 32 + (16 \times 4) + (7 \times 1) + (16 \times 5)[/tex]
=246g
no. moles of CuSo4. 5H2O=
[tex] \frac{mass}{mass \: of \: 1mole} [/tex]
so moles
=
[tex] \frac{3.14}{246} [/tex]
0.013 mole
in the equation
1 mole of sulphuric acid reacts to form 1 mole of CuSo4.5H2O
in other words
0.013 mole of sulphuric acid reacts to form 0.013 mole of CuSo4.5H2O
so mass of 1 mole (Mr) H2So4=
[tex](2 \times 1) + 32 + (16 \times 4)[/tex]
98g
mass of sulphuric acid= mole × mass of 1 mole
so mass= 0.013 × 98
1.274 g
b) In the equation
1 mole of sulphuric acid reacts to form 1 mole of copper(ll) oxide
in other words
0.013 mole of sulphuric acid reacts to form 0.013 mole of copper (ll) oxide
so 0.013 mole of copper(ll) oxide is reacted
Hope it helped and pls mark brainliest
Need help ASAP!!!! what is the value (angle) for the C=C=O bond in Ketene i.e. CH2=C=O
Answer:
[tex]180^\circ[/tex] by the VSEPR theory.
Explanation:
This question is asking for the bond angle of the [tex]\rm C=C=O[/tex] bond in [tex]\rm H_2C=C=O[/tex]. The VSEPR (valence shell electron pair repulsion) theory could help. Start by considering: how many electron domains are there on the carbon atom between these two bond?
Note that "electron domains" refer to covalent bonds and lone pairs collectively.
Each nonbonding pair (lone pair) of valence electrons counts as one electron domain.Each covalent bond (single bond, double bond, or triple bond) counts as exactly one electron domain.For example, in [tex]\rm H_2C=C=O[/tex], the carbon atom at the center of that [tex]\rm C=C=O[/tex] bond has two electron domains:
This carbon atom has two double bonds: one [tex]\rm C=C[/tex] bond and one [tex]\rm C=O[/tex] bond. Even though these are both double bonds, in VSEPR theory, each of them count only as one electron domain. Keep in mind that there are only four valence electrons in each carbon atom. It can be shown that all four valence electrons of this carbon atom are involved in bonding (two in each of the two double bonds.) Hence, there would be no nonbonding pair around this atom.In VSEPR theory, electron domains around an atom repel each other. As a result, they would spread out (in three dimensions) as far away from each other as possible. When there are only two electron domains around an atom, the two electron domains would form a straight line- with one domain on each side of the central atom. (To visualize, consider the three atoms in this [tex]\rm C=C=O[/tex] bond as three spheres on a stick. The central [tex]\rm C[/tex] atom would be between the other [tex]\rm C[/tex] atom and the [tex]\rm O[/tex] atom.)
This linear geometry corresponds to a bond angle of [tex]180^\circ[/tex].
if 140cm3 of methane diffuse into air in 72 sec,how long will it take 210cm3 of sulphur dioxide to diffuse under the same condition ?
Answer:
time for sulphur dioxide to diffuse is 221.05 secs
The time for sulphur dioxide to diffuse is 108 sec.
Which gas diffuses twice quickly as SO2?Sulfur dioxide has a molecular weight of sixty-four and as a result, the square root is 8. since its inversely proportional, on the way to diffuse two times as fast, the rectangular root of the molecular weight should be 4, and subsequently the molecular weight might be 16. So the solution is methane (CH4).
Which gases diffuse the fastest?The charge of diffusion for a gas is inversely proportional to the rectangular root of its molecular mass (Graham's law). The gasoline with the lowest molecular weight will effuse the fastest. The lightest, and consequently fastest, fuel is helium.
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what's love like? what feels are involved?
first ionization energy
Answer:
The first ionization energy is defined as
Energy which is required to pull out one mole of the outermost shell's electrons in a neutral atom from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+.[tex]A\to A^++ e^{-}[/tex] , where A is any neutral atom.In the periodic table, Its value decreases from top to bottom in groups and increases from left to right across a particular period. Helium has the largest first ionization energy.Francium has one of the lowest.PLZ HELP SUPER STUCK T^T *will give brainiest* (30 points) (plz hurry!! its on a test)
Question: Aluminum is an element. Which best describes what makes up a sample of aluminum? one kind of atom two different kinds of atoms all carbon-based atoms a carbon atom and non-carbon atoms
Answer:
The answer to this is A. One kind of atom
Explanation:
The other options make no sense whatsoever. But enjoy.
I hope this helped.
Answer:
A. One kind of atom
Explanation:
The proof that ch4 is a weak acid
Answer: because ch4 is not considered a acid they said it is too weak
Explanation:
hurry I'm on a timer
Which term describes erosion?
O creates small particles
O hardens rock fragments
O transports solid materials
O dissolves rock components
Answer:
transports solid materials
Explanation:
Erosion is a process where solid materials are transported by natural forces such as wind or water.
Answer: c
Explanation:
in Analytical chemistry laboratory. Nickle(ppm)in water sample estimated by two different students was as ,student 1 (25 24 24 24 24 28 26 ) and student 2 (24 25 24 24 25 25 ), if the true valude on Nickle in water was 20 ppm estimate the precision and accuracy of both students
Answer:
Answers are in the explanation
Explanation:
Precision and accuracy are both statistical concepts. Precision is about how close are the measured values to each other. Accuracy is closeness of the measured values to a specific value or reference value.
There are many ways to calculate precision and accuracy, one is stimating precision as Relative Uncertainty and accuracy as Relative Error.
Formulas are:
Relative Uncertainty: Standard desviation / Measured value.
Relative Error: Measured Value - Expected Value / Expected value
Measured value is the aveage of the values.
For student 1:
Mean = 25
Standard desviation = 1.5275
Relative Uncertainty: 1.5275 / 25
Relative Uncertainty: 0.061
Relative Error: 25 - 20 / 20
Relative Error: 0.25
For student 2:
Mean = 24.5
Standard desviation = 0.5477
Relative Uncertainty: 0.5477 / 24.5
Relative Uncertainty: 0.02
Relative Error: 24.5 - 20 / 20
Relative Error: 0.225
As the student 2 has a low Relative error and uncertainty, you can say student 2 is more accurate and precise
Modern atomic theory states that atoms are neutral. How is this neutrality achieved? (3 points) Select one: a. Equal number of neutrons and protons b. Equal number of protons and electrons c. More electrons than protons d. More neutrons than electrons
Answer:
The answer is option B.
Equal number of protons and electronsHope this helps you
Answer:
equal number of electrons and protons
Explanation:
electron is negatively charged and proton is positively charged for an atom to stay neutrality # of electrons and protons must be equal.
While camping you light a small campfire, initiating the combustion of wood to produce heat and
light. What can you determine about this reaction?
O A. It is exothermic.
B. The bond making energy is more than 600 kJ.
OC. It is endothermic.
D. The bond breaking energy is more than 600 kJ.
Answer:
A. It is exothermic
Explanation:
Combustion is a chemical reaction in which a substance combines with oxygen present in air to produce carbon (iv) oxide and water as well release heat and light energy.Combustion is an exothermic process.
An exothermic reaction releases energy in the form of heat to the surroundings. The energy required to break bonds in the reactants is less than the energy required to form new bonds in the products in an exothermic reaction.
From the given options;
A. It is exothermic is determinable since the reaction is a combustion reaction
B. The bond making energy is more than 600 kJ is not certain because the mass of the wood being burnt is not given. Also, wood is not composed of a specific element that would be taking part in the reaction, rather it is composed of various substances.
C. It is endothermic. is wrong because combustion of wood is exothermic.
D. The bond breaking energy is more than 600 kJ is not certain because the mass of the wood being burnt is not given. Also, wood is not composed of a specific element that would be taking part in the reaction, rather is composed of many substances.
A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion. B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion. C. If Assertion is true statement but Reason is false. D. If Assertion is false and Reason is true i Assertion: .Burning of magnesium ribbon produce whitish powder called magnesium oxide. Reason : Magnesium is generally cleaned by rubbing it on sand paper
Answer:
C. If Assertion is true statement but Reason is false.
Explanation:
The burning of magnesium in air produces magnesium oxide as shown by the equation;
2Mg(s) + O2(g) -----> 2MgO(s)
The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.
The reason has nothing at all to do with the assertion hence the answer given.
Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.
Answer:
Answer:
C. If Assertion is true statement but Reason is false.
Explanation:
The burning of magnesium in air produces magnesium oxide as shown by the equation;
2Mg(s) + O2(g) -----> 2MgO(s)
The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.
The reason has nothing at all to do with the assertion hence the answer given.
Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.
Explanation:
When a sample of Mg is combusted in a bomb calorimeter, 25.4 kJ of energy as heat is evolved. The calorimeter contains 7.50 x 102 g of water at an initial temperature of 18.6 °C. The specific heat capacity of water is 4.184 J/gLaTeX: \cdot⋅°C and the heat capacity of the bomb is 8.20 x 102 J/°C. Calculate the final temperature of the water and the bomb
Answer:
x = 25.02 or 25°c
Explanation:
Given:
mass of water : 7.50×10² =750 gm
Ccal = 8.20× 10² = 820 J/°c
Let assume final temp = x°c
then, heat gained by the water + heat gained by calorimeter
= 25400 J
⇒ Mw × Cw× ΔTw+ Ccal ×ΔT = 25400
⇒ 750× 4.184 × (x - 18.6) + 820 ×(x-18.6) = 25400
⇒ x = 25.02 or 25°c
Consider the equation below.
Zn + H2SO4 → ZnSO4 + H2
The mole ratio of zinc to zinc sulfate is
Answer:
1:1
Explanation:
There is one mole of zinc (Zn) and one mole of zinc sulfate (ZnSO₄).
The mole ratio is 1:1.
Hope this helps.
Answer:
1:1
Explanation:
How much energy does a 185 nm wave of light have? (The speed of light in a
vacuum is 3.00 x 108 m/s, and Planck's constant is 6.626 x 10-34 Jos.)
A. 1.07 x 10-18 J
B. 8.38 x 1034j
C. 9.31 x 1017 J
D. 3.68 x 10-32 J
O
Answer: A. 1.07 x 10∧ -18 J
Explanation:
The energy can be calculated by using this relation; E = hc / ∧
Where E = energy
h = Planck's constant = 6.626 x 10-34joules
c = speed of light = 3.00 x 10∧8 m/s
∧ = wavelenght = 185 nm = 185 x 10∧ -9m
Therefore; E= hc / ∧
= (6.626 x 10-34 j/s) x ( 3.00 x 10∧8 m/s) / 185 x 10∧ -9m
= 1.987 x 10 ∧ -25 / 185 x 10∧ -9m
= 1.07 x 10∧ -18 J
How to calculate this ?
Do you use the molar mass and multiply it by the mass given ?
Answer:
Option C. 8.91g
Explanation:
The balanced equation for the reaction is given below:
2Pb(NO3)2 —> 2PbO + 4NO2 + O2
Next, we shall determine the mass of Pb(NO3)2 that decomposed and the mass PbO produced from the balanced equation.
This is illustrated below below:
Molar mass of Pb(NO3)2 = 207 + 2[14 + (16x3)]
= 207 + 2[14 + 48]
= 207 + 2[62] = 207 + 124
= 331g/mol
Mass of Pb(NO3)2 from the balanced equation = 2 x 331 = 662g
Molar mass of PbO = 207 + 16 = 223g/mol
Mass of PbO from the balanced equation = 2 x 223 = 446g
Summary:
From the balanced equation above,
662g of Pb(NO3)2 decomposed to produce 446g of PbO.
Finally, we can obtain the maximum mass of lead(II) oxide, PbO produced from 13.23g of lead (II) nitrate, Pb(NO3)2 as follow:
From the balanced equation above,
662g of Pb(NO3)2 decomposed to produce 446g of PbO.
Therefore, 13.23g of Pb(NO3)2 will decompose to produce = (13.23 x 446)/662 = 8.91g of PbO.
Therefore, 8.91g of PbO were obtained from the decomposition of 13.23g of Pb(NO3)2
4.Acrylic fibres are also known as
a)Terry cot
b)Orlon
c)Polyester
d)None of these
Answer:
B
Explanation:
DuPont created the first acrylic fibers in 1941 and trademarked them under the name Orlon.
When 12 g of methanol (CH3OH) was treated with excess oxidizing agent (MnO4-), 14 g of formic acid (HCOOH) was obtained. Using the following chemical equation, calculate the percent yield. (The reaction is much more complex than this; please ignore the fact that the charges do not balance.)
3CH3OH + 4MnO4- ----> 3HCOOH + 4MnO2
(a) 100%
(b) 92%
(c) 82%
(d) 70%
(e) 55%
Answer:
(c) 82%
Explanation:
Using the chemical reaction:
3CH₃OH + 4MnO₄⁻ → 3HCOOH + 4MnO₂ + 4e⁻
3 moles of methanol produce 3 moles of formic acid (Reaction 1:1)
To find the percent yield we need to calculate theoretical yield of the reaction when 12g of methanol (Molar mass: 32.04g/mol) are reacting, thus:
12g ₓ (1mol / 32.04g) = 0.3745 moles of methanol are in 12g.
As 1 mole of methanol produce 1 mole of formic acid, assuming a 100% of yield in the reaction (Theoretical yield) moles produced of formic acid are 0.3745 moles.
Using molar mass of formic acid (46.03g/mol), mass of the acid in 0.3745moles are:
0.3745 moles ₓ (46.03g/mol) = 17.2g of formic acid are theoretical yield
Percent yield is calculated as:
(actual yield / Theoretical yield) × 100
As actual yield of the reaction is 14g. Theoretical yield is:
(14g / 17.2g) × 100 = 81.2% ≈ 82%
Right answer is:
(c) 82%The percentage yield of the reaction is 82%
The correct answer to the question is Option C. 82%
We'll begin by writing the balanced equation for the reaction.
3CH₃OH + 4MnO₄⁻ → 3HCOOH + 4MnO₂ + 4e⁻
Molar mass of CH₃OH = 12 + (3×1) + 16 + 1 = 32 g/mol
Mass of CH₃OH from the balanced equation = 3 × 32 = 96 g
Molar mass of HCOOH = 1 + 12 + 16 + 16 + 1 = 46 g/mol
Mass of HCOOH from the balanced equation = 3 × 46 = 138 g
From the balanced equation above,
96 g of CH₃OH reacted to produce 138 g of HCOOH
Next, we shall determine the theoretical yield of HCOOH.From the balanced equation above,
96 g of CH₃OH reacted to produce 138 g of HCOOH.
Therefore,
12 g of CH₃OH will react to produce = (12 × 138)/96 ≈ 17g of HCOOH.
Finally, we shall determine the percentage yield.Actual yield of HCOOH = 14 g
Theoretical yield of HCOOH = 17 g
Percentage yield =?Percentage yield = Actual / Theoretical × 100
Percentage yield = 14/17 × 100
Percentage yield ≈ 82%The correct answer to the question is Option C. 82%
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is a process that involves the collection of information and ideas supported by evidence.
Science
Systematics
Pseudoscience
Hypothesis
Answer:
pseudoscience
Explanation:
srry that this is so late btw, hope this helps...
Answer:
Science
Explanation:
First response is NOT correct
Acid rain is the direct result of acid released by burning fossil fuels.
Please select the best answer from the choices provided
ОТ
OF
Answer:
The answer is TrueHope this helps you
I need a help from this question!!
Answer:
B
Explanation:
Please take a look at the picture attached for the drawings and structures.
C2H4 is a alkene (C-C double bond). When steam (water) is added, it turns into an alcohol, where the double bond breaks and a (-OH) functional group is attached to one of the Carbons. In this case, C2H4 ethene is turned into ethanol.
When an alcohol undergoes oxidation, primary alcohols turn into aldehyde (-CHO) or carboxylic acids (-COOH). Secondary alcohol turns into ketone. Ethanol is a primary alcohol. And since it later reacts with propanol, it can only form carboxylic acid when it oxidizes. The product in this reaction is ethanoic acid.
Carboxylic acid reacts with alcohol to form an ester (-COO-). the -COOH group from acid combines with the -OH group from alcohol to form an ester bond -COO- while eliminating H2O. Therefore, when propanol undergoes esterification with ethanoic acid, propyl ethanoate is produced. It is the answer of B.
Which will change will cause the gravitational force between a baseball and a soccerball
How are the properties of metals and non-metals different?
Answer:
Explanation:
Properties of metals:
1. They have a lustre ( shine )
2. They have a silvery-grey or golden-yellow colour.
3. They conduct heat and electricity.
4. They are ductile ( can be drawn into wires ) .
5.They are malleable ( can be hammered into thin sheets ).
6. They are sonorous ( make a ringing sound when hit ).
Properties of non-metals:
1. They display a variety of colours.
2. They are poor conductors of heat and electricity.
3. They are not lustrous, ductile or malleable.
Hope it helps
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Determine the net iconic equation for the following chemical reaction: HCl(aq) + NH4OH(aq)———-> NH4Cl(aq) + H2O(I) Hint: HCl(aq) is strong acid NH4OH(aq) is a weak base
Answer : The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,
[tex]HCl(aq)+NH_4OH(aq)\rightarrow NH_4Cl(aq)+H_2O(l)[/tex]
The ionic equation in separated aqueous solution will be,
[tex]H^+(aq)+Cl^-(aq)+NH_4^+(aq)+OH^-(aq)\rightarrow H_2O(l)+NH_4^+(aq)+Cl^-(aq)[/tex]
In this equation, [tex]NH_4^+\text{ and }Cl^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
Anyone know how to answer this?
Answer:
i metal
ii nonmetal
iii metal
iv nonmetal
Explanation:
If you look up what the element of a heater is, you get a picture of some sort of rod. It's the heating element of the heater, and must be some type of metal to conduct electricity and warm up. Fishing rods are made of either fiberglass, graphite, or carbon fibre. These are nonmetals. In order for a lightning rod to conduct electricity and bring the lightning down to the ground, it has to be metal. You wouldn't want a metal oven mitt, as that would burn your hand.
A drug problem can quickly consume A)a small portions of a person income B)the bulk of a person income C)a person excess income
Answer:
b
Explanation:
a drug problem consumes the bulk of a persons income because drugs are expensive to buy
A drug problem can quickly consume the bulk of a person income
What is a drug problem?A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drug abuse or substance abuse refers to the use of certain chemicals for the purpose of creating pleasurable effects on the brain.
Drug use can have significant and damaging short-term and long-term effects. Taking some drugs can be particularly risky, especially if you take high doses or combine them with other drugs or alcohol.
People of any age, sex or economic status can become addicted to a drug. Certain factors can affect the likelihood and speed of developing an addiction.
The best way to prevent an addiction to a drug is not to take the drug at all. If your doctor prescribes a drug with the potential for addiction, use care when taking the drug and follow the instructions provided by your doctor. Thus you can save your income.
The correct answer is option B.
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Name one way chemicals can help the environment
Energy storage and transport. Chemical energy transport.
Answer:
to clean the water
Explanation:
How do you find the amount of electrons for any element?
Answer:
If you know the number of protons and neutrons you have to simply subtract the number of neutrons by number of protons the answer will be number of neutron
Explanation:
Answer:
We can find the amount of electrons through its Atomic number and with the help of electronic configuration
Which refers specifically to a heated solution that holds more dissolved solution than it can hold at a lower temperature? supersaturated undersaturated heterogeneous homogeneous
Answer:
A. Supersaturated
Explanation:
i got it right on edge 2021
The heated solution that holds more dissolved solution than it can hold at a lower temperature is supersaturated solution. Therefore, option A is correct.
What is supersaturated solution ?A solution that contains more solvent than the typical amount that can dissolve at a specific temperature is said to be supersaturated. By introducing a tiny solute crystal known as a seed crystal, the excess dissolved solvent in a super-saturated solution can begin to recrystallize.
A solution that contains more solvent than the typical amount that can dissolve at a specific temperature is said to be supersaturated. A solution is considered supersaturated if it contains more solute than is necessary to saturate it.
A solution that contains more solute than it can hold at a specific temperature is said to be supersaturated. Usually, raising a solution's temperature causes more particles to dissolve, increasing the solute concentration.
Thus, option A is correct.
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Which of the following is a characteristic property of the halogen? A. They are very reactive B. They are very stable C. They are metals D. They are all gases
Answer:A
Explanation:
They are very reactive is a characteristic property of halogen.
Hence, Option (A) is correct answer.
What is Halogen ?Halogens are non metallic elements in periodic table. It belongs to group 17 in the periodic table. Halogen family consists six elements that is Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At) and Tennessine (Ts).
What are the characteristics property of halogen ?They are nonmetals. Halogens have 7 valence electrons. They are highly reactive with alkaline earth metal and alkali metals. Halogens are not stable.Thus, from the above conclusion we can say that They are very reactive is a characteristic property of halogen.
Hence, Option (A) is correct answer.
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