Multiple choice
I genuinely have no idea-- but I don't think it's the first one or the last.
I think it may be the third one but I'm not too sure.
Answers
Answer:
The correct option is;
By first reversing Reaction 2 and then adding the enthalpy of Reaction 1 and the enthalpy of reaction 2
Explanation:
The given reactions are;
1) C₂H₂ (g) + 2H₂ (g) → C₂H₆ (g) [tex]{}[/tex] ΔH = -75 kcal
2) C₂H₄ (g) + H₂ (g) → C₂H₆ (g) [tex]{}[/tex] ΔH = -33 kcal
3) C₂H₂ (g) + H₂ (g) → C₂H₄ (g) [tex]{}[/tex] ΔH = ?
By reversing reaction (2) and subtracting the reactants from the products we then have followed by adding the enthalpy of reaction 1 to the value of the enthalpy of the (reversed) reaction 2, we have;
C₂H₂ (g) + 2H₂ (g) → C₂H₆ (g) [tex]{}[/tex] ΔH = -75 kcal
C₂H₆ (g) → C₂H₄ (g) + H₂ (g) [tex]{}[/tex] ΔH = 33kcal
Adding, and cancelling out the italicized terms which are repeated in the product and reactants, we get
C₂H₂ (g) + H₂ (g) → C₂H₄ (g) [tex]{}[/tex] ΔH = -75 kcal + 33 kcal = -42 kcal
Therefore, the correct option is "by first reversing Reaction 2 and then adding the enthalpy of Reaction 1 and the enthalpy of reaction 2"
Related Questions
Write the name and symbol of the ion formedwhen a sulfur atom gains two electrons. a.an aluminum atom loses three electrons. b.a nitrogen atom gains three electrons. c.a calcium atom loses two electrons.
Answers
Answer:
SULFUR: S²-
ALUMINIUM: Al³†
NITROGEN: N³-
CALCIUM: Ca²†
a) Of options (a) - (d) below, highlight the (unbalanced) chemical equation that represents
the combustion reaction of cellulose (like what we see with the wood burning in a
campfire above)
a) O, + H2O → C + CH1,05 + CO2
b) C6H100, + O2 + C + CO, + H,O
c) CH4,05 + CO2 → C+ O2 + H,O
d) CO, + H2O → C.H.O. + O2
Answers
Answer:
c...............
Explanation:.............................yuuuuuuuuuuuuuuuuuuuuuwoopuuuuuuuu
What is the noble gas electron configuration of bismuth (Bİ)?
OA [Kņ6s 6p
OB. e] 6s 6p
Oc. pke) 4l4 5d0 6s 6p
OD. [Kr] 5 5105p5 6s 6d10 6p?
OE. e) 6s5d0 6p
Answers
Answer: [Xe] 6s^2 6p^3
Explanation: The noble gases are on the last column of the periodic table and Xenon (Xe) is the noble gas before Bismuth (Bi). Then you go down to the next row which is 6s^2 and 6p^3.
Answer:
The correct answer is {Xe] 4f14 5d10 6s2 6p3
Explanation:
What forms when two atoms combine? PLEASE HELP!!!!!!!
A. a molecule
B. a nucleus
C. a proton
D. an electron
Answers
Answer:
Option A - nucleus
Explanation:
A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different elements, we call that a compound. All compounds are molecules, but not all molecules are compounds.
Two atoms combine to form a molecule.
What is a molecule?
Molecule is two or more atoms connected by chemical bonds and form the smallest unit of a substance that retains the composition and properties of that substanceThe atoms can be the same like in oxygen molecule - An oxygen molecule has 2 oxygen atomsThe atoms can be different like in a water molecule - A water molecule has 2 hydrogen and 1 oxygen atomWhat is a nucleus?
The nucleus is positively charged region at the center of the atomIt consists of two types of subatomic particles packed together. The particles are protons and neutronsProton has a positive charge and neutron is electrically neutralWhat is a proton?
A proton is a subatomic particle found in nucleus of every atomProtons have a positive electric charge The number of protons in each atom is its atomic numberWhat is an electron?
It was discovered by English physicist J.J.Thomson Electron is a negatively charged subatomic particle that can be either bound to an atom or freeThey exist outside the nucleusThey are significantly smaller in mass and have both wave-like and particle-like characteristicsLearn more about Molecules at https://brainly.com/question/13348791
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Which of the following is NOT a sign of a chemical reaction?
A. Change in color
B. Change in size
C. Bubble formation
D. A temperature change
Answers
1. How many grams are in 0.20 moles of N,?
Answers
Answer:
[tex]\boxed {\boxed {\sf About \ 2.8 \ grams \ of \ nitrogen}}[/tex]
Explanation:
To convert from moles to grams, we must use the molar mass.
1. Molar Mass
The molar mass of an element can be found on the Periodic Table. We are looking for nitrogen or N.
Nitrogen (N): 14.007 g/mol2. Convert from moles to grams
Use the molar mass as a ratio or fraction.
[tex]\frac{14.007 \ g \ N}{1 \ mol \ N}[/tex]
Multiply the given number of moles (0.20) by the fraction we just made.
[tex]0.20 \ mol \ N *\frac{14.007 \ g \ N}{1 \ mol \ N}[/tex]
When multiplied, the moles of nitrogen will cancel each other out.
[tex]0.20*\frac{14.007 \ g \ N}{1}[/tex]
The denominator of 1 can be ignored to create a simple multiplication problem.
[tex]0.20 *14.007 \ g \ N[/tex]
[tex]2.8014 \ g \ N[/tex]
3. Round
The original measurement of moles (0.20) gives 2 significant figures, the last 2 and 0.
Therefore, we must round our answer to 2 sig figs. This is the tenths place for this number of grams we found.
[tex]2.8014 \ g \ N[/tex]
The 0 in the hundredth place tells us to leave the 8 in the tenth place.
[tex]\approx 2.8 \ g\ N[/tex]
There are about 2.8 grams of nitrogen in 0.20 moles of nitrogen.
Which graph represents the function f(x) = 2|x|?
Answers
Answer:
It will look like a v starting the at point (0,0) with a slope of 2
Explanation:
Answer:
look at the graph
Explanation:
hope this helps, pls mark brainliest :D
which of the following gas samples would have the largest number of representative particles at STP?
a) 0.10 L Xe
b) 0.007 L SO3
c) 12.0 L He
d) 7.0 L O2
Answers
c) 12.0 L He would have the largest number of representative particles at STP
Further explanationGiven
The gas samples
Required
The largest number of particles
Solution
The largest number of particles = the largest amount of moles
At STP 1 mole = 22.4 L and 1 mole = 6.02 x 10²³ particles
Quickly we will be able to determine that option C has the largest number of particles because it has the largest number of volumes
or we can find the mole of each gas sample
Let's find each mole of the gas sample
a. 0.10 L Xe
[tex]\tt \dfrac{0.1}{22.4}=0.0045[/tex]
b. 0.007 L SO3
[tex]\tt \dfrac{0.007}{22.4}=0.00031[/tex]
c. 12.0 L He
[tex]\tt \dfrac{12}{22.4}=0.536[/tex]
d. 7 L O2
[tex]\tt \dfrac{7}{22.4}=0.313[/tex]
Is the specimen classified as living or non-living? Use three pieces of evidence and reasoning to justify your answer. Provide 3 out of the 7 characteristics of life criteria to use as evidence.
Answers
Answer: All living things move in some way. This may be obvious, such as animals that are able to walk, or less obvious, such as plants that have parts that move to track the movement of the sun. All living things grow. Earthworms hatch from eggs and can grow up to a metre or more in length! Some earthworms are also able to regrow small parts of their body that have been lost or injured. Chromists are a diverse group of plant-like organisms and range from very small to very large. They are found in almost all environments.
Explanation: I hope that helped yall!
What happens if you were to swallow a small amount if wet nail polish? Answer truthfully in your own words.
Answers
Answer:
I'm pretty sure you'll be fine
Explanation:
I've swallowed more than a small amount and I'm ok sort of
true or false? British commander Henry Hamilton was also
known as the "hair buyer" because he paid his
soldiers to cut their own hair.
if it is false give an explanation to why it is false
Answers
That is true he was known as the hair buyer
Answer:
its true.
i did it on edg 2020
What type of glassware is useful for transferring liquids from the large stock container to a smaller container such as a graduated cylinder
Answers
Answer:
Beaker
Explanation:
In the laboratory, we often need to transfer liquids from a large stock container to a graduated cylinder in order to measure a specific volume of liquid.
This is done using a beaker. A beaker is a lipped cylindrical glass container for laboratory use (Oxford dictionary).
Hence, when transferring liquids from the large stock container to a smaller container such as a graduated cylinder, we use a beaker.
8.0 dm of NO is mixed with 6.0 dm3 of O, at room temperature and pressure (RTP).
The reaction below takes place until one of the reactants is used up.
2NO(g) + O2(g) + 2NO,(9)
What is the volume of the mixture at RTP after the reaction has taken place?
A)8.0 dm3
B)10.0 dm3
C)12.0 dm3
D)14.0 dm3
Answers
Answer:
B)10.0 dm3
Explanation:
Now we have to apply Gay-Lussac's law which states that gases combine in simple volumes provided the temperature and pressure remain constant.
2NO(g) + O2(g) ------>2NO
combining volumes 2 : 1 : 2
Volumes before reaction 8.0 6.0 0.0
Reacting volumes 8.0 4.0 8.0
Volumes after reaction - 2.0 8.0
Therefore;
Total volume after reaction = 2.0 + 8.0 = 10.0 dm^3
The volume of the mixture after the reaction is 10 dm³
The correct answer to the question is Option B. 10 dm³
The above is simply a demonstration of Gay-Lussac' law. The volume of the mixture after the reaction can be obtained as follow:
2NO(g) + O₂ —> 2NO(g)
Combining Vol: 2 dm³ : 1 dm³ : 2 dm³
Before reaction: 8 dm³ : 6 dm³ : 0
During reaction: 8 dm³ : 4 dm³ : 8 dm³
After reaction: 0 dm³ : 2 dm³ : 8 dm³
The Volume after the reaction = 2 + 8 = 10 dm³
Learn more about Gay-Lussac's law:
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multiple choice-- please help!
Study the chemical reaction.
A ⟶ B + C
This reaction is second order in A.
What is the rate law for this reaction?
Rate = K [B][C]^2
Rate = K [A]^2
Answers
The rate law for the reaction : r=k.[A]²
Further explanationGiven
Reaction
A ⟶ B + C
Required
The rate law
Solution
The rate law is a chemical equation that shows the relationship between reaction rate and the concentration / pressure of the reactants
For the second-order reaction it can be:
1. the square of the concentration of one reactant.
[tex]\tt r=k[A]^2[/tex]
2. the product of the concentrations of two reactants.
[tex]\tt r=k[A][B][/tex]
And the reaction should be(for second order) :
2A ⟶ B + C
Thus, for reaction above (reactant consumption rate) :
[tex]\tt r=-\dfrac{\Delta A}{2\Delta t}=k[A]^2[/tex]
why is carbon dioxide a green house gas
Answers
Answer:
That's because the glass walls of the greenhouse trap the Sun's heat. The greenhouse effect works much the same way on Earth.
Explanation:
Gases in the atmosphere, such as carbon dioxide, trap heat just like the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.
aspirin is a compound that contain carbon,hydrogen and oxygen. It is uesd as painkiller. An aspirin tablet contain 1.25×10³⁰ molecule. How many moles of this compound are present in the tablet
Answers
n= number of mole
avogrado constant= 6.12x10^-23
you will get 2.042 x 10^52
Answer:
Number of molecules = 1.25 x 10 30 molecules
Avogadro’s number = 6.022 x 10 23
Number of moles = ?
Formula
Number of moles = 1.25 x 10 30
6.022 x 10 23
= 2.07 x 106 moles
Explanation:
Which of the following reactions would result in increased entropy?
Answers
Answer:
A option
Explanation:
Because recatants are in solid form having less enetropy and products are liquid form having more entropy
While other options reactants and products are in same phase gas phase having same entropy
The reaction that would result in increased entropy is the combustion reaction;
KNO3(s)--->K+(aq)+NO3-(aq). Option A
This is further explained below
What is a combustion reaction?Generally, a combustion reaction is simply a combustion process that occurs when a material combines with oxygen gas, producing energy as light and heat.
In conclusion, the chemical reaction KNO3(s)--->K+(aq)+NO3-(aq) is has all properties of a combustion reaction as the solid reactants gives an aq solution.
Read more about Chemical reaction
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which of the following has the smallest radius? K+, K, Rb, Rb+
Answers
:
Option (c) is the correct answer.
Explanation:
It is known that when we move down a group then there is increase in size of atom. This is because there occurs increase in number of shells in the atom.
Also, when an atom loses electrons then it acquires a positive charge and size of the atom decreases. On the other hand, when an atom gain electrons then it acquires a negative charge and size of the atom increases.
Since, both Rb and K are same group elements and Rb has larger atomic size than K.
Hence, we can conclude that out of the given options K^{+}
+ has the smallest size.
Answer:
K+
Explanation:
Just took the quiz :)
which description shows copper at rtp?
a) stationary and closed together
b) stationary and randomly arranged
c)vibrating and in a regular arrangement
d) vibrating and in a random arrangement
Answers
Answer:
c)vibrating and in a regular arrangement
Explanation:
Copper is a chemical element represented by the symbol Cu and having atomic number 29. Copper is a transition metal which means its subshells are not completely filled and that is why they are vibrating in the room temperature. But copper is a solid at room temperature with regular arrangement of atoms.
Hence, the correct answer is "c)vibrating and in a regular arrangement".
While working in the lab, you observe the following volume.
What is the value that should be recorded?
Select one:
a)17.4 mL
b)18.4 mL
c)13.4 mL
d)19.4 mL
Answers
Answer:
B 18.4L
Explanation:
Answer:
The answer is 18.4 mL
The liquid is between 19 and 17
so the answer will be 18.4 mL
Help me pleasee!!!!! (revised)
Answers
Answer:
bal2 is the correct answer hope this hlps have a great rest of your day.
Explanation:
When hydrogen gas reacts with oxygen gas, the potential energy diagram for the reaction will appear more to which of the following?
Answers
Answer:
Maybe is D....
Explanation:
When the hydrogen peroxide decomposed,it graph such as A so maybe the formation of hydrogen peroxide is opposite direction as the A....Hope can help you.....
Balance the following chemical
equation by providing the correct
coefficients.
[ ]FeBr3 + [ ]Na2S → [ ]Fe2S3 + [ ]NaBr
Answers
Answer:
Explanation:
A chemical formula can be defined as a notation that is used to show which element and how many is contained in a chemical compound.
Also, in chemistry, the sum of charges of the anion and the cation of any ionic compound is always equal to zero.
A chemical equation is considered to be balanced when the amount of reactants on the left is equal to the amount of products on the right.
Therefore;
[2]FeBr3 + [3]Na2S → [1]Fe2S3 + [6]NaBr
In the above chemical equation, we will balance the reactants in the chemical equation with the smallest coefficients possible;
[tex] 2FeBr_{3} + 3Na_{3}S ----> Fe_{2}S{3} + 6NaBr [/tex]
Two (2) moles of Iron (III) Bromide reacts with two (2) moles of Sodium Sulfide to form Iron (III) Sulfide and Sodium Bromide.
A serving of Frosted Flakes cereal contains 235,000 J of energy. Calculate the change in temperature (ΔT) that would occur if this food was used to heat 1,000 grams of water.
Answers
The change in temperature (ΔT) : 56.14 ° C
Further explanationGiven
Cereal energy = 235,000 J
mass of water = 1000 g
Required
the change in temperature (ΔT)
Solution
Heat can be formulated :
Q = m . c . ΔT
c = specific heat for water = 4.186 J / gram ° C
235000 = 1000 . 4.186 . ΔT
[tex]\tt \Delta T=\dfrac{235000}{1000\times 4.186}=56.14^oC[/tex]
When enthalpy of reactants is higher than the product then the reaction will be.
Answers
Answer:
The reaction will be endothermic represented by a positive (+) sign
Which of the following parts of a forest ecosystem could not become a fossil?
A. twigs that dropped from trees
B. a dead mouse
C. a puddle
D. deer footprints in the soil
Answers
The parts of a forest ecosystem could not become a fossil are; deer footprints in the soil and a puddle.
A fossil is formed from the remains of plants and animals that have died. Anything that is not plant or animal material can never be turned into fossil. Fossil is rich in carbon.
A puddle just refers to a percolation of water. A puddle and deer footprints in the soil are not of plant or animal origin.
As such, deer footprints in the soil and a puddle could not become a fossil.
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what do african snails eat
Answers
Answer:
hope it helps you a little
aluminiuim is obtained industrially by the electrolysis of aluminium oxide heated to high temperatures. explain the meaning of the term electrolysis.
Answers
Answer: When an electric current is passed through a substance to effect a chemical change.
4 Fe + 3 O2 --> 2 Fe2O3
How many grams of Fe will react with 40.0 grams of O2?
Answers
Answer:
93.33 g of Fe
Explanation:
The balanced equation for the reaction is given below:
4Fe + 3O₂ —> 2Fe₂O₃
Next, we shall determine the masses of Fe and O₂ that reacted from the balanced equation. This can be obtained as follow:
Molar mass of Fe = 56 g/mol
Mass of Fe from the balanced equation = 4 × 56 = 224 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mass of O₂ from the balanced equation = 3 × 32 = 96 g
SUMMARY:
From the balanced equation above,
224 g of Fe reacted with 96 g of O₂.
Finally, we shall determine the mass of Fe required to react with 40 g of O₂. This can be obtained as follow:
From the balanced equation above,
224 g of Fe reacted with 96 g of O₂.
Therefore, Xg of Fe will react with 40 g of O₂ i.e
Xg of Fe = (224 × 40)/96
Xg of Fe = 93.33 g
Therefore, 93.33 g of Fe is required to react with 40 g of O₂.
Is it physically possible to create a chemical serum that would give you any sort of superpower??
Answers
Trying to make anything like that would ultimately kill you— it would have to be natural talent.
I hope this helped!
I would appreciate it if you gave me a Thanks and a great brainliest (: