Answer:
2 moles of MgCl2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
Mg + 2HCl —> MgCl2 + H2
Now, we can determine the number of mole MgCl2 produced from 4 moles of HCl as follow:
From the balanced equation above,
2 moles of HCl reacted to produce 1 mole of MgCl2.
Therefore, 4 moles of HCl will react to produce = (4 x 1)/2 = 2 moles of MgCl2.
Therefore, 2 moles of MgCl2 were produced from the reaction of 4 moles of HCl.
A blacksmith heated an iron bar to 1445 °C. The blacksmith then tempered the metal by dropping it into 42,800 mL of
water that had a temperature of 22.00 °C. The final temperature of the system was 45.00°C. What was the mass of
the iron bar? (Hint: Density of water is 1.00 g/mL) The specific heat capacity for iron is 25.01 J/mol°C.
Answer:
6626 g
Explanation:
Given that:
Density of water = 1.00 g/ml, volume of water = 42800 ml.
Since density = mass/ volume
mass of water = volume of water * density of water = 42800 ml * 1 g/ml = 42800 g
Initial temperature of water = 22°C and final temperature of water = 45°C.
specific heat capacity for water = 4.184 J/g°C
ΔT water = 45 - 22 = 23°C
For iron:
mass = m,
specific heat capacity for iron = 0.444 J/g°C
Initial temperature of iron = 1445°C and final temperature of water = 45°C.
ΔT iron = 45 - 1445 = -1400°C
Quantity of heat (Q) to raised the temperature of a body is given as:
Q = mCΔT
The quantity of heat required to raise the temperature of water is equal to the temperature loss by the iron.
Q water (gain) + Q iron (loss) = 0
Q water = - Q iron
42800 g × 4.184 J/g°C × 23°C = -m × 0.444 J/g°C × -1400°C
m = 4118729.6/621.6
m = 6626 g
molecular formula of ammonia crisscross method
Answer:
Explanation:The molecular formula of ammonia is NH3
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.
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.
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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
Which refers to the density of the medium’s particles at the compression of a sound wave? A.amplitude B.pitch C.volume D.wavelength
Answer:
A is the answer.
Explanation:
The sound wave is a longitudinal wave which travels in the form of compression and rarefaction . The point where the particles are closer to each other is called compression and the point where the particles are far apart from each other is called rarefaction.
Answer:
Amplitude
Explanation:
Amplitude describes the displacement of the medium's particles. The higher the amplitude, the more dense it is, and the lower the amplitude, the less dense it is.
Pitch is incorrect because it describes the sound
Volume is incorrect because it describes the sound.
Wavelength is incorrect because it describes the distance between a period of a wave.
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.
all electromagnetic radiation: A. can travel through empty space B. travels at the same speed in a vacuum C.consists of photons D. all of the above
Answer:
A. can travel through empty space
Explanation:
it is said dat electro magnetic waves or radiation travels through the vacuum of space
Answer:
all of the above. Because, Y'know, electromagnetic radiation is like that.
Lipase is a protein that helps the body break down fats in foods. Lipase is best classified as which type of protein? an enzyme an antibody a structural protein a binding protein.
Its for edg please answer quickly if you can
Answer:
an enzyme
Explanation:
just took it on edge
Lipase is an enzyme protein which contains amino acids that helps the body break down fats in foods.
What is an amino acid?Amino acids are defined as the substances which are considered to be the monomers of proteins.Every amino acid has the same structure consisting of a central carbon which is bonded to an amino group , carboxyl group and a hydrogen.
Each amino acid also has another atom or a group of atoms bonded to the alpha carbon which are also known as the R group or the variable group of the side chain.There are 20 common amino acids present in natural proteins and each amino acid has the same backbone.
The sequence and number of amino acids determines protein's shape,size and also its function. Each amino acid is attached to the other by a covalent bond formed by a dehydration reaction.
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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)
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
How many moles of iron (III) hydroxide are produced when 5.0 moles of sodium hydroxide reacts with excess iron (III) chloride? FeCl3 + 3NaOH —> Fe(OH)3 + 3NaCl
Answer:
1.67 moles of iron (III) hydroxide are produced when 5.0 moles of sodium hydroxide reacts with excess iron (III) chloride.
Explanation:
The balanced reaction is:
FeCl₃ + 3 NaOH ⇒ Fe(OH)₃+ 3 NaCl
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reagents and products participate in the reaction:
FeCl₃: 1 moleNaOH: 3 molesFe(OH)₃: 1 moleNaCl: 3 molesThen you can apply the following rule of three: if 3 moles of NaOH form 1 mole of Fe(OH)₃, 5 moles of NaOH how many moles of Fe(OH)₃ do they form?
[tex]moles of Fe(OH)_{3} =\frac{5 moles of NaOH*1 mole of Fe(OH)_{3} }{3 moles of NaOH}[/tex]
moles of Fe(OH)₃= 1.67
1.67 moles of iron (III) hydroxide are produced when 5.0 moles of sodium hydroxide reacts with excess iron (III) chloride.
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
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.
Hexane and hexene are hydrocarbon compounds from different homologous series. the combustion of these two compounds produce different amount of soot. explain the difference based on the percentage of carbon by mass.
Answer:
Percentage of carbon of alkene is higher compared to the alkane that has the same number of carbon per molecule. Because of this, combustion of alkene will produce more sooty flame compared to their corresponding alkane and because Alkenes have a higher percentage of carbon compared to their corresponding alkane.
Explanation:
Relative atomic mass : C= 12 and H=1
Percentage of Carbon Hexane (C6H14)
Percentage of Carbon = 83.7 percent
6(12) x 6(12) +14(1) x 100 percent= 83.7 percent
Percentage of Carbon Hexene = 85.7 percent
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.
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:
DUE IN 30 MINUTES!!! (please keep it short if you can, if not its ok.) What is the molar mass of Pb(SO4)2? Explain how you calculated this value. (4 points)
Answer:
399
Explanation:
Pb(SO4)2 contains 1 atom of Pb, 2 atoms of S and 8 atoms of O. So, atomic mass of Pb(SO4)2 is 207 + 64 + 128 = 399 u. Therefore, molar mass of Pb(SO4)2 is 399 g/mol.HOPE THIS helps. Good Luck
Answer:
The molar mass of Pb(SO₄)₂ is 399.32.
Explanation:
To find the molar mass of Pb(SO₄)₂, you have to find the molar mass of each individual element that makes up the compound.
Let's start by figuring out how many of each element is present in the compound.
Pb (lead) - 1
S (sulfur) - 2
O (oxygen) - 8
(SO₄)₂ is a polyatomic ion. It is written in parentheses followed by a subscript of 2. This means that there are two sulfate ions in the compound. So, the number of sulfur atoms and oxygen atoms doubles. (1 × 2 = 2) and (4 × 2 = 8).
Next, look up the molar mass of each element on a periodic table and multiply it by the number of atoms present.
Pb - 207. 2 × 1 = 207. 2
S - 32.06 × 2 = 64.12
O - 16.00 × 8 = 128
Lastly, add up them all together to get the molar mass.
207. 2 + 64.12 + 128 = 399.32
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.
Jack tries to place magnets on his refrigerator at home, but they won’t stick. What could be the reason?
Answer:
The body of the refrigerator isn’t made of magnetic material.
Explanation:
Same reason why a magnet doesn't stick to a paper or a plastic is the reason behind why Jack's refrigerator is acting out because may be it isn't made of magnetic materials like iron, steel etc, but rather made up of non magnetic things like porcelain, wood etc.
sodium chloride is called an electrovalent compound where as carbon dioxide is called covalent compound why
Electrovalent compounds are those that are created when one or more electrons are transferred from one atom to another inside the compound. NaCl is an electrovalent substance because it shares an electron with other compounds to produce them.
What are compounds ?A material created by chemically joining two or more distinct components. Examples of compounds are table salt (NaCl), which is generated from the elements sodium and chloride, and water (H2O), which is created from the components hydrogen and oxygen.
One carbon atom and two oxygen atoms combine to form carbon dioxide. One carbon dioxide molecule contains four covalent connections. Because neither carbon nor oxygen are metals, we can infer that carbon dioxide is a covalent molecule.
Pure substances known as compounds are created chemically when two or more elements are combined in a specific mass proportion. Chlorine and sodium combine to form sodium chloride (common salt).
Thus, sodium chloride is called an electrovalent compound whereas carbon dioxide is called covalent compound.
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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:
:)
Representa la unión iónica entre los siguientes átomos: 1) Bromo y Potasio 2) Calcio y Oxígeno 3) Cloro y Magnesio 4) Sodio y Flúor 5) Aluminio y Nitrógeno Ayuda por favoor
Answer:
a. KBr
b. CaO
c. MgCl₂
d. NaF
e. NH₃
Explanation:
a. 2K + Br₂ = 2KBr
b. 2Ca + O₂ = 2CaO
c. Mg + Cl₂ = MgCl₂
d. 2Na + F₂ = 2NaF
d. N₂ + 3H₂ = 2NH₃
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
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
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
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
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
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%
Which type of reaction does this diagram represent? (picture)
Answer:
its A.addition
Explanation:
edg. 2020 other guy is wrong