Answer:
Explanation:
The reaction undergoing least change in volume will have lowest change in entropy .
1 ) C₂H₂(g) + 5/2O₂(g) → 2CO₂(g) + H₂O(g)
change in volume = 2.5 +1 - ( 2 + 1 ) = 0.5
2 ) CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)
change in volume = 2 +1 - ( 2 + 1 ) = zero
3 ) C₂H₆(g) + 7/2O₂(g) → 2CO₂(g) + 3H₂O(g)
change in volume = 3 +2 - ( 3.5 + 1 ) = 0.5
4 ) C₂H₄(g) + 3O₂(g) → 2CO₂(g) + 2H₂O(g)
change in volume = 2 +2 - ( 3 + 1 ) = zero
Hence least change in volume is in case no - 2 and 4 .
In reaction
C₂H₄(g) + 3O₂(g) → 2CO₂(g) + 2H₂O(g) and
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)
∆S° or change in entropy is least .
Which question would most likely be studied by a physicist?
A. Were there ever any living organisms on Mars?
B. How can the forces on a space probe be controlled so it will land
on Mars?
O C. What type of substances make up the soil on Mars?
O D. Should the government spend taxpayers' money to send space
probes to Mars?
Answer:A
Explanation: Were there any living organisms is the answer because physics is the study of matter,its motion and behaviour of space and time and some other topics like energy and force.
Answer:
B
Explanation:
Forces and vectors on a probe are a physics thing
River's chemistry class is doing an experiment in which the students create a 30% hydrochloric acid mixture by mixing a certain amount of 25% solution with a different amount of 50% solution. The amount of 25% solution used is 20 liters less than 5 times the amount of 50% solution used. How much of the 25% solution and the 50% solution are needed in all
Answer:
20 liters of 50% solution and 80 liters of 25% solution
Explanation:
Let x litres be the amount of 50% solution to be used.
Since the amount of 25% solution used is 20 liters less than 5 times the amount of 50% solution used, then the 25% solution would be (5x -20) litres.
Therefore, 50x + 25(5x-20) = 30(x + 5x-20)
50x + 125x - 500 = 30x + 150x - 6 00
175x - 500 = 180x - 600
Collecting like terms
180x - 175x = 600 - 500
5x = 100
x = 20
Therefore, volume of 50% solution needed = 20 litres
Volume of 25% solution needed = (5 * 20) - 20 = 80 litres
20 liters of 50% solution and 80 liters of 25% solution
Calculate the payback time if she insulates the loft with 300 mm insulation when: area of loft space = 100m^2 cost of roll of 100 mm thick loft insulation that covers 8.3m^2 = £20 cost of putting the insulation into the loft = £120 savings per year = £80 per 100 mm Payback Time = installation cost divided by annual savings
Answer: Payback time = 0.0075
Explanation: Since payback time is calculated as:
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
First determine the installation cost:
100 mm thick insulation covers 8.3 m². Then 300 mm covers 24.9 m².
To cover 8.3m² costs £20. Then, the cost to cover 24.9 m² is:
cost = [tex]\frac{20*24.9}{8.3}[/tex]
cost = £60
The cost of putting the insulation is £120, so the total cost is:
total cost = £60 + £120
total cost = £180
Savings per year per 100 mm thick is £80. For 300 mm, the value of annual savings is:
savings = [tex]\frac{300*80}{100}[/tex]
savings = 240
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
payback time = [tex]\frac{180}{240}[/tex]
payback time = 0.75
PLEASE HELP I NEED THE ANSWERS WITH THE WORK ITS WORTH 50 POINTS!!!!! 1. How much energy would be required to melt 15.0 g of ice at 0 oC? ΔHfus= 6.00 kJ/mol 2. How many moles of ice at 0 oC could be melted with the addition of 750 KJ of energy? ΔHfus= 6.00 kJ/mol 3. How much energy would it take to boil 36.0 g of water at 100 oC? ΔHvap= 40.7 kJ/mol 4. How many grams of steam could be condensed at 100 o C with the removal of 307 kJ of energy? ΔHvap= 40.7 kJ/mol 5. How much energy is needed to make 254 g of iodine melt? ΔHfus= 7.76 kJ/mol 6. How much energy is needed to make 4.24 g of lead melt? ΔHfus= 4.77 kJ/mol
Answer:
1) 5 kJ
2) 125 moles
3) 81.33 kJ
4) 135.9 grams
5) 15.165 kJ
6) 97.6 J
Explanation:
1) Molar mass of ice (water) = 18.015 g/mol
Number of moles, n, of ice = mass/(molar mass) = 15/18.015 = 0.833 moles
ΔHfus = 6.00 kJ/mol
Energy required, E = ΔHfus × n = 0.833 × 6 = 4.996 ≈ 5 kJ
2) Number of moles of ice that can be melted by E = 750 kJ is given by the equation;
n = E/(ΔHfus) = 750/6 = 125 moles
3) Given that ΔHvap = 40.7 kJ/mol, we have;
Number of moles of water, n = 36/18.015 = 1.998 ≈ 2 moles
Heat required = ΔHvap × n = 40.7 × 2 = 81.33kJ
4) Given that heat removed, ΔH= 307 kJ, we have;
n = ΔH/ΔHvap = 307/40.7 = 7.543 moles
Mass of water = Number of moles × Molar mass = 7.543 × 18.015 = 135.9 grams
5) Energy required, E for iodine to melt = Number of moles of iodine × ΔHfus of iodine
Number of moles of iodine = Mass of iodine/(Molar mass of iodine)
Number of moles of iodine = 248/126.9 = 1.954 moles
Energy required, E for iodine to melt = 1.954 × 7.76 = 15.165 kJ
6) Energy required, E for 4.24 g of lead to melt = Number of moles of lead × ΔHfus of lead
Number of moles of lead= Mass of lead/(Molar mass of lead)
Number of moles of iodine = 4.24/207.2 = 0.0205 moles
Energy required, E for iodine to melt = 0.0205 × 4.77 = 9.76 × 10⁻² kJ = 97.6 J.
6.3 kJ of energy is required to increase the temperature of some water from 60 °C to 75 °C. The specific heat capacity of water is 4200 J per kg per °C. What is the mass of the water?
Answer:
Mass of the water = 0.1kg is 100g
Explanation:
Mathematically;
Quantity of heat = mass of water * specific heat capacity * temperature change
From the question, we identify the following;
Quantity of heat = 6.3 KJ
1 KJ = 1000 J, so 6.3 KJ = 6.3 * 1000 = 6300 J
Mass of water = ?
Specific heat capacity = 4200
Temperature change is the difference between the final and initial temperature. = 75-60 = 15
6300 = m * 15 * 4200
63 = m * 15 * 42
63 = 630 m
m = 63/630
m = 0.1 kg
Which part of the electromagnetic spectrum is nearest to X-rays? microwaves infrared light gamma rays radio waves
Answer:
The correct answer to the following question will be Option A (Microwaves).
Explanation:
This tends to be a source of radiation, including some signals, infrared radiation, x-rays as well as gamma. This appears to have a diverse variety of uses, involving communications, radar, and scheduling, but best known by most individual people. Sections of society used handheld devices, including tablets, as well as WiFi.The other given choices are not related to the given circumstances. So that option A seems to be the appropriate one.
Answer:
its a
Explanation:
what is Lfusion in the equation Q=mLfusion
Answer:
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
Explanation:
Latent heat is basically termed as hidden heat. It is defined as the amount of heat required to change 1 g of a substance at the temperature of its melting point from the solid to the liquid state at constant temperature.The formula that relates heat and latent heat of fusion is given by :[tex]Q=mL_{\text{fusion}}[/tex]
Here,
m is mass of substance
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
Based on the bond energies for the reaction below, what is the enthalpy of the reaction? HC≡CH (g) + 5/2 O₂ (g) → 2 CO₂ (g) + H₂O (g) **Any help would be greatly appreciated!**
Answer:-1222kj
Explanation:
Based on the bond energies, the reaction HC≡CH(g) + 5/2 O₂(g) → 2 CO₂(g) + H₂O(g) has a standard enthalpy of reaction of -1222 kJ/mol.
Let's consider the following reaction.
HC≡CH(g) + 5/2 O₂(g) → 2 CO₂(g) + H₂O(g)
Given the bond energies (E), we can calculate the standard enthalpy of the reaction (ΔH°rxn) using the following expression.
[tex]\Delta H\° _{rxn} = E(broken\ bonds) - E(formed\ bonds)[/tex]
The broken bonds are:
HC≡CH
1 triple C-C bond2 single C-H bondsO₂
5/2 double O-O bondsThe formed bonds are:
CO₂
4 double C-O bondsH₂O
2 single O-H bonds[tex]\Delta H\°_{rxn} = E(C\equiv C) + 2 E(C-H) + 5/2 E(O=O) - 4 E(C=O) - 2 E(O-H)\\\\\Delta H\°_{rxn} = 835kJ/mol + 2 (411kJ/mol) + 5/2 (494kJ/mol) - 4 (799kJ/mol) - 2 (459kJ/mol) = -1222 kJ/mol[/tex]
Based on the bond energies, the reaction HC≡CH(g) + 5/2 O₂(g) → 2 CO₂(g) + H₂O(g) has a standard enthalpy of reaction of -1222 kJ/mol.
Learn more: https://brainly.com/question/24857760
In which situation would hydrogen bonding be present?
A. When hydrogen exists as an ion in solution
O B. When hydrogen is attached to C, S, or P
C. When hydrogen is attached to N, F, or o
D. When hydrogen atoms bond together to form H2
Answer:
c
Explanation:
hydrogen Bond exist between ammoia, hydrogen fluoride and water so the answer is c
c. Write a complete ionic equation for the reaction and identify the spectator ions.
The required complete ionic equation of the reaction
Pb(NO3)2+2KI---->PbI2+2KNO3 is Pb2+(aq) + 2 I−(aq) → PbI2(s)
What is ionic equation?A chemical equation in which the electrolytes in aqueous solution are expressed as dissociated ions.
Spectator ions in above equation are as follows- K +and NO3−
Define spectator ions.
Ions that are not involved in the actual chemical reaction are called spectator ions.
Net ionic equation of given reaction isPb⁺²+2I ⁻¹⟶PbI₂It shows only the ions which involves in the chemical reaction.
Therefore, K⁺ and NO3⁻ are spectator ions.
Learn more about spectator ions ,here:
https://brainly.com/question/22277121
#SPJ2
molecular formula of ammonia crisscross method
Answer:
Explanation:The molecular formula of ammonia is NH3
What can you infer about the results of numerical models in 1966 for polar caps
made of water ice?
Answer:
Those people could sustain on Mars, by living closer to the poles
Explanation:
As it is given that caps involve the water ice instead of the carbon dioxide
And, current observations of spectrum analyzed that the polar caps are totally different from one other i.e northern one involves more water ice while on the other hand, the southern one involves most of the carbon dioxide
Moreover, the astronomers unable to see to spectrum portions as the atmosphere absorbs the wavelength
So we conclude that the people could survive on mars if they live near to poles
write about group in chemistry
Answer:
Explanation:
Symmetry can help resolve many chemistry problems and usually the first step is to determine the symmetry. If we know how to determine the symmetry of small molecules, we can determine symmetry of other targets which we are interested in. Therefore, this module will introduce basic concepts of group theory and after reading this module, you will know how to determine the symmetries of small molecules.
Introduction
Symmetry is very important in chemistry researches and group theory is the tool that is used to determine symmetry. Usually, it is not only the symmetry of molecule but also the symmetries of some local atoms, molecular orbitals, rotations and vibrations of bonds, etc. that are important. For example, if the symmetries of molecular orbital wave functions are known, we can find out information about the binding. Also, by the selection rules that are associated with symmetries, we can explain whether the transition is forbidden or not and also we can predict and interpret the bands we can observe in Infrared or Raman spectrum.
Symmetry operations and symmetry elements are two basic and important concepts in group theory. When we perform an operation to a molecule, if we cannot tell any difference before and after we do the operation, we call this operation a symmetry operation. This means that the molecule seems unchanged before and after a symmetry operation. As Cotton defines it in his book, when we do a symmetry operation to a molecule, every points of the molecule will be in an equivalent position.
Symmetry Elements
For different molecules, there are different kinds of symmetry operations we can perform. To finish a symmetry operation, we may rotate a molecule on a line as an axis, reflect it on a mirror plane, or invert it through a point located in the center. These lines, planes, or points are called symmetry elements. There may be more then one symmetry operations associated with a particular symmetry
Identity E
The molecule does not move and all atoms of the molecule stay at the same place when we apply an identity operation, E, on it. All molecules have the identity operation. Identity operation can also be a combination of different operations when the molecule returns to its original position after these operations are performed.1 This will be demonstrated later.
Dada la configuración electrónica de un elemento 1s2 2s2 2p6 3s2 3p6 3d10 4s1, se puede deducir si tendrá a formar enlaces de tipo: A)Ninguna de las anteriores B )Iónico y covalente C)Metálico y covalente D)Iónico y metálico
Respuesta:
D) Iónico y metálico
Explicación:
Consideremos al elemento con la configuración electrónica 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹.
Como el electron diferencial está en el nivel 4, el elemento está en el Periodo 4.
Como hay 1 electrón en el último nivel, el elemento esta en el Grupo 1.
El elemento en esa posición es el Potasio, que es un metal, por lo que puede formar enlaces metálicos con metales y enlaces iónicos con no metales.
mass is 89.6 grams (g), and its volume is 10 cubic centimeters (cm3). What’s the density of the sample?
Explanation:
density = mass/volume
density = 89.6/10
density = 8.96g/cm³
Which term describes this reaction? addition condensation elimination substitution
Answer:
Addition
Explanation:edg 2020
Answer:
The correct answer is A.
Explanation:
Edge 2022
Answer the following questions based on their
electronic configuration.
a) 1s2 2s2 2p 2 b) is 2 2s 2 2p4
i) Write the name of the compound, its molecular
formula and type of chemical bond formed by
the combination of these two elements. Also
write down the balanced chemical reaction when
the above compound reacts with water.
Answer:
the molecular formula is CO2
The bond formed is covalent bond
CO2+H2O = H2CO3
The reaction between the compound and water will give us carbonic acid (H2CO3)
a heating fan is supplied with 150 j of electricity which is nonverts to 113 j of thermal energy and 37 j of sound energy
How efficient is the heating fan?
Answer:
Heating Fan is 75.33% efficient.
Explanation:
As it is mentioned that the given fan is a HEATING FAN, it means the it is used for provided heat (thermal energy) to the surrounding. Hence, its efficiency depends upon how much heat/thermal energy is provides.
We can state that.
Total Energy provided = 150 J
Useful Energy = 113 J
Wasted Energy = 37 J
The efficiency of the heating fan can be given by following formula:
Efficiency = ( Useful Energy / Total Energy ) × 100
Efficiency = ( 113 J / 150 J) × 100
Efficiency = (0.7533)× 100
Efficiency = 75.33%
As transformações estão presente em nosso cotidiano, elas nunca param de acontecer, na sua maioria invisível a olho nu.Quais critérios é preciso observar para identificar se ocorreu transformação?
Answer:
Explanation:
as transformações parecem invisíveis por causa do nível de organização da vida. A célula é a unidade básica da vida, a célula é invisível e todas as mudanças são resultado da formação de novas células no ser vivo.
sea water boiling below 100 degrees celsius true or false
Answer:
Explanation:
its true
hope this helps
plz mark as brainliest!!!!!
Answer:
True
Explanation:
After 273 m3 of ethylene oxide at 748 kPa and 525 K is cooled to 293 K, it is allowed to expand to 1100. m3. The new pressure is _____kPa
Answer:
[tex]\large \boxed{\text{104 kPa}}[/tex]
Explanation:
To solve this problem, we can use the Combined Gas Laws:
[tex]\dfrac{p_{1}V_{1} }{n_{1}T_{1}} = \dfrac{p_{2}V_{2} }{n_{2}T_{2}}[/tex]
Data:
p₁ = 748 kPa; V₁ = 273 m³; n₁ = n₁; T₁ = 525 K
p₂ = ?; V₂ = 1100. m³; n₂ = n₁; T₂ = 293 K
Calculations:
[tex]\begin{array}{rcl}\dfrac{p_{1}V_{1}}{n_{1} T_{1}} & = & \dfrac{p_{2}V_{2}}{n_{2} T_{2}}\\\\\dfrac{\text{748 kPa}\times \text{273 m}^{3}}{n _{1}\times \text{525 K}} & = &\dfrac{p_{2}\times \text{1100. m}^{3}}{n _{1}\times \text{293 K}}\\\\\text{390.0 kPa} & = &3.754{p_{2}}\\p_{2} & = & \dfrac{\text{390.0 kPa}}{3.754}\\\\ & = & \textbf{104 kPa} \\\end{array}\\\text{The new pressure is $\large \boxed{\textbf{104 kPa}}$}[/tex]
What is equilibrium?? Give examples
Answer:
it is when a state in which opposing forces or influences are balanced.
A example of equilibrium is in economics supply and demand are equal.
Explanation:
Answer:
Compromise of 1850
Explanation:
HELP Which statement describes an effect of large asteroid and comet impacts? They may cause continents to move. They may cause small craters on Earth’s surface. They may cause changes limited to within the crater. They may kick up dust and pollute Earth’s atmosphere.
Answer: D
Explanation:
The statement that describes the effect of large asteroid and comet impacts is they may kick up dust and pollute Earth’s atmosphere. The correct option is D.
What are asteroids?
Asteroids are the small, big rocks that are made up of dust, and rocks. They orbit the sun and are smaller than a planet. An asteroid hits the earth like 65 million years ago. When asteroids and comets hit the earth's surface, they create large or small craters.
Comets are small or large snowy balls of gases. They are made up of rocks, and dust, and they orbit the sun. They orbit the sun. A comet has three parts, a nucleus, a comma, and a tail. When it comes near the sun, it converts into a burning ball of gases.
Thus, the correct option is D. They may cause small craters on Earth’s surface.
To learn more about asteroids, refer to the link:
https://brainly.com/question/2826424
#SPJ6
How much energy is required to vaporize 1.5 KG of aluminum
Answer:
The amount of energy required to vaporize 1.5 kg of aluminium is 16.345 GJ
Explanation:
Given that the heat of vaporization of aluminium, ΔHvap = 294000 kJ/mol
Mass of the given aluminium = 1.5 kG = 1500 g
Number of moles of aluminium = Mass of aluminium/(Molar Mass of aluminium)
Molar Mass of aluminium = 26.98 g/mol
Therefore, we have;
Number of moles = 1500/26.98 = 55.6 moles
The energy required = The heat of vaporization of aluminium × Number of moles of aluminium
The energy required = 294000 × 55.6 = 16345441.0675 kJ = 16.345 GJ.
Answer:
1650 kJ
Explanation:
Q = ΔH vaporization (for Al) x m
Q = 1100 kJ/kg x 1.5 kg = 1650 kJ
Which of the following is the best definition of a physical change?
A. Something that can be observed or measured while changing the identity of the substance.
B. A nail rusting.
C. A change that occurs without changing the identity of the substance.
D. Ice melting into water.
Answer:
the answer is D.ice melting into water
how many atoms are contained in 2.70g of aluminum provided that 32g of sulphur equals 6.02 × 10^(23)atoms
Answer:
[tex]1.63 \times {10}^{24} [/tex]
one atom of an element = 6.02 \times {10}^{23} atom
The mass of one atom of sulphur = 32g
The mass of one atom of aluminium = 27g
so one atom of aluminium = 6.02 \times {10}^{23}
27g of AL = 6.02 \times {10}^{23} atom
2.70g of AL = X atoms
Then you cross multiply ........
and get the answer
.
We would like to make a golden standard kilogram in the shape of circular cylinder. The density of gold is 19.32 g/cm3. a) Find the volume of the kilogram standard of gold in cubic meter. b) In order to minimize the effect of surface contamination, the height of this golden standard kilogram is equal to its diameter. Find the height of this golden standard kilogram in mm.
Explanation:
a) Using the provided information about the density of gold, the sample size, thickness, and the following equations and comersion factors, find the area of the gold leaf:
[tex]V=l \cdot w \cdot h=A \cdot h\\m=\rho \cdot V[/tex]
Gold [tex]_{\rho}=19.32 \mathrm{g} / \mathrm{cm}^{3}[/tex]
[tex]1 \mu=10^{-6} \mathrm{m}[/tex]
First, find the volume of the sample and then find the area of the sample.
[tex]V=\frac{m}{\rho}=\frac{27.6 \mathrm{g}}{19.32 \mathrm{g} / \mathrm{cm}^{3}} \cdot\left(\frac{0.01 \mathrm{m}}{1 \mathrm{cm}}\right)^{3}[/tex] [tex]=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}[/tex]
[tex]V=A \cdot h \rightarrow A=\frac{V}{h}=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}{10^{-6} \mathrm{m}} \approx 1.429 \mathrm{m}^{2}[/tex]
b. Using the provided information from part [tex]a[/tex] ), the radius of the cylinder, and the following equation for the volume of a cylinder, find the length of the fiber :
[tex]V=\pi r^{2} h \rightarrow h=\frac{V}{\pi r^{2}}[/tex]
[tex]h=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}{\pi \cdot\left(2.5 \times 10^{-6} \mathrm{m}\right)^{2}} \approx 72778 \mathrm{m}[/tex]
Question 4 of 10
Which two gases are trace gases in the atmosphere?
O A. Nitrogen
I B. Neon
O C. Oxygen
D. Methane
Answer:
Neon and Methane
Explanation:
Nitrogen and Oxygen made up way over half of the atmosphere so it's without a doubt, not those two. Precisely, Nitrogen makes up 78% of the atmosphere while oxygen makes up 21%
Answer: neon and methane
Which explains the change in ionization energy that occurs between removing the first and second electrons from an atom?
Answer:
"The strength of ionization decreases as the proportion including its protons to the excited electrons" is the right solution.
Explanation:
The ionizing procedure, the creation of ions through manipulating individual atoms or revolutionaries, or through decreasing or increasing charged particles in something other than gas by intense electrical fields.It should be the total removal of someone with an electron through an atomic nucleus rather than from molecules. The corresponding molecule has denominated an ion.This question seems incomplete. I believe the answer choices are as followed:
O The ionization energy decreases because the ratio of the protons to electrons increases.
O The ionization energy increases because the ratio of the protons to electrons increases.
O The ionization energy decreases because the ratio of the protons to electrons decreases.
O The ionization energy increases because the ratio of the protons to electrons decreases.
The answer to this is The ionization energy increases because the ratio of the protons to electrons increases. (2nd option).
The ____ cycle is not a nutrient cycle
Answer:
Water cycle
Explanation:
The water cycle, also called as the hydrologic cycle that describes the continual flow of water i.e on over and beyond the surface of the Earth.
The nutrient cycle refers to the cycle in which there is a movement and exchange of organic and inorganic matter
Therefore the water cycle is not a nutrient cycle and hence the same is to be considered
Answer:
water cycle
Explanation:
:)