Answer:
weakest to strongest
dispersion forces dipole-dipole interactionshydrogen bonding covalent bondingExplanation:
Covalent bonding is an intramolecular interactions that hold the atoms together. Dispersion forces, hydrogen bonding and dipole-dipole interactions are intermolecular interactions . Intramolecular interactions are stronger than intermolecular interactions .
Dipole-dipole interactions occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule. They are relative strong.
Hydrogen bonding is a special kind of dipole-dipole interaction that occurs specifically between a hydrogen atom bonded to either an oxygen, nitrogen, or fluorine atom. It is the strongest dipole-dipole interaction.
Dispersion forces exist between all types of molecules, whether ionic or covalent (polar or nonpolar). They are the weakest of the intermolecular forces.
Freezing and Boiling are endothermic processes. This means that these processes absorb energy from their surroundings in order to occur. Use this information and the data you collected in the Phase Change Gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.
Hi my dear friend,
Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing. When steam, which is gaseous water, condenses, heat is released. Likewise when liquid water freezes, heat is given off. In fact heat must be continually removed from the freezing water or the freezing process will stop.
~Thank you
How do forensic scientists determine the time of death? There are timely pieces of evidence that help scientists with this task. At the time of death:
~The heart stops
~The skin gets tight and grey in color
~Cell start to die (brain 3-7 min; skin up 24 hours)
~The muscles relax
~The bladder and bowels empty
And then what? Order these changes from FIRST to LAST.
I have done some research as well as asking some friends. This is what I came up with. Not sure if it is 100% correct.
step = time after death
1. Livor Mortis = 20-30 minutes
2. Eyes film (cloud) = 2 hours
3. Rigor Mortis begins = 4-6 hours
4. Empty small intestines = 12 hours
5. Bloating = 3-5 days
6. Decay
Forensic scientists determine the time of death initially by observing physical changes such as the heart stopping, greying of the skin, cell death, muscle relaxation, and the emptying of the bladder and bowels. The sequence of these events helps establish a timeline. Additional factors like insect activity, weather conditions, and the setting may further assist in making an accurate estimation.
Explanation:Forensic scientists, specifically forensic anthropologists and forensic pathologists, determine the time of death by analyzing various changes that occur in the body after death. These changes occur in a specific sequence and at different rates, thereby providing a means to estimate the time of death. The sequence of changes are as follows:
The heart stops: The absence of a heartbeat may be the most immediate signal of death.The skin gets tight and grey in color: This happens immediately after the heart stops. The greying is due to blood pooling and coagulating in the body after the heart stops pumping.Cell death begins: Brain cells start dying within 3-7 minutes of the heart stopping due to a lack of oxygen. Skin cells can survive up to 24 hours after death.Relaxation of the muscles: Shortly after death, all the muscles in the body relax. Rigor mortis, or the stiffening of the muscles, begins 3-4 hours after death and can last up to 72 hours.Emptying of the bladder and bowels: This is not always immediate and can occur at various times postmortem, usually within the first few hours to a day.In addition to these changes, forensic scientists also study other evidence such as insect activity, weather conditions and surroundings to calculate the postmortem interval or to validate their findings based on the body's changes.
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A volcano erupts which term best describes the rock that will eventually form on the surface
PLEASE SHOW WORK and include units on each number
Ammonia (NH3) reacts with oxygen (O2) to produce nitrogen monoxide (NO) and water (H2O). Write and balance the chemical equation. How many liters of NO are produced when 2.0 liters of oxygen reacts with ammonia? Show all work!
Answer is: 1.6 liters of NO are produced.
Balanced chemical reaction: 4NH₃ + 5O₂ → 4NO + 6H₂O.
V(O₂) = 2.0 L; volume of oxygen.
From balanced chemical reaction: n(O₂) : n(NO) = 5 : 4.
V(O₂) : V(NO) = n(O₂) : n(NO).
2.0 L : V(NO) = 5 : 4.
V(NO) = 2 L · 4 ÷ 5.
V(NO) = 1.6 L; volume of nitrogen (II) oxide.
How much heat can be obtained from the condensation of 36.2 g of methanol vapor (MM = 32.04 g/mol) at its boiling point to 36.2 g of liquid methanol at the same temperature? â†Hvap = 35.2 kJ/mol Cliquid = 2.533 J/gâ—¦C Cgas = 44.06 J/gâ—¦C
Answer:
q = -39.8 kJ
Step-by-step explanation:
CH₃OH(g) ⇌ CH₃OH(l); ΔH(cond) = -35.2 kJ·mol⁻¹
(1) Calculate the moles of methanol
n = 36.2 × 1/32.04
n = 1.130 mol
=====
(2) Calculate the heat evolved
q = nΔH(cond)
q = 1.130 × (-35.2)
q = -39.8 kJ
A single atom of an element has 21 nutrons 20 electtons and 20 protons which element is it
your element would be calcium
What is the angle between the carbon-chlorine bonds in the phosgene ( cocl2 ) molecule?
Answer: The angle between the carbon-chlorine bonds in phosgene will be 120°
Explanation: Formula used to calculate the hybridization:
[tex]{\text{Number of electron pairs}} =\frac{1}{2}[V+N-C+A][/tex]
where,
V = number of valence electrons present in central atom i.e. carbon = 4
N = number of monovalent atoms bonded to central atom = 2
C = charge of cation = 0
A = charge of anion = 0
For [tex]COCl_2[/tex]
[tex]{\text{Number of electron pairs}} =\frac{1}{2}[4+2-0+0]=3[/tex]
The number of electron pairs are 3 which means that the hybridization will be [tex]sp^2[/tex] and the electronic geometry of the given molecule will be trigonal planar.
The bond angle in this electronic geometry is 120°
The structure of phosgene is attached below.
The angle between the Carbon-Chlorine bonds in the Phosgene molecule (COCl₂) is generally 120 degrees due to the sp² hybridization of the Carbon Atom
Explanation:The phosgene molecule (COCl₂) has a planar shape, with the oxygen atom in the center, bonded to the carbon atom, and the chlorine atoms bonded to either side of the carbon atom. This creates a molecule with a structure in the shape of the letter 'V'. The angle between the carbon-chlorine bonds in the phosgene molecule is typically 120 degrees. This is due to the fact that the carbon atom in the center is sp² hybridized, meaning it has three regions of electron density spread out in a plane, forming angles of 120 degrees with each other.
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When the equation Fe3O4+AI > AI2O3+Fe is correctly balanced what is the coefficient of Fe
The answer is 9 please rate 5 ⭐️ if it was helpful.
For each pair below, select the sample that contains the largest number of moles .
If you need the answer to this problem you need to post more information about the problem.
Answer:
Pair A: B
Pair B: A
Pair C: B
Which element has the strongest intermolecular forces at room temperature? A) I (s) B) F (g) C) Br (l) D) Cl (l)
A) I or Iodine
Iodine is solid which will be in a more fixed position and held closer together making it harder to break apart. It has more electrons and therefore more van der waals forces acting on it, which require more energy to break apart.
answer: a. I
explanation: iodine is a solid meaning the particles are closer together and holds a more fixed position, making it harder to break apart unlike a liquid or gas where the particles are more spread apart
2AgNO3 (s) + MgCl2 (aq) --> 2AgCl (s) + Mg(NO3)2 (aq) The student starts with 50.0 grams of mgcl2 and an excess of AgNO3. If she makes 125.1g of AgCl, what is her percent yield?
The percent yield is 83.12%
calculation
percent yield = actual yield / theoretical yield x 100
actual yield =125.1 g
Theoretical yield is calculated as below
Step 1: find the moles of MgCl₂
moles = mass÷ molar mass
from periodic table the molar mass of mgCl₂ =24.3 +(35.5 x2) =95.3 g/mol
moles = 50.0 g÷ 95.3 g/mol =0.525 moles
Step 2: use the mole ratio to determine the moles of AgCl
from given equation MgCl₂: AgCl is 1:2
therefore the moles of AgCl = 0.525 x2/1 =1.05 moles
Step 3: find the theoretical mass AgCl
mass = moles x molar mass
from periodic table the molar mass of Agcl = 107.87 +35.5 =143.37 g/mol
mass = 1.05 moles x 143.37 g/mol =150.5 grams
The percent yield is therefore = (125.1 g/150.5) x 100 = 83.12%
How many grams of carbon monoxide are needed to react with an excess of iron (III) oxide to produce 198.5 grams of iron? Fe2O3(s) + 3CO(g) -----> 3CO2(g) + 2Fe(s) Show all work step by step please!
The grams of carbon monoxide that are needed to react is 148.68 grams
calculation
Step 1: find the moles of iron
moles =mass÷ molar mass
from periodic table the molar mass of Fe is 56 g/mol
= 198.5 g÷ 56 g/mol =3.54 moles
Step 2: use the mole ratio to determine the moles of carbon monoxide(Co)
that is from given equation Co : Fe is 3:2 therefore the moles of Co
= 3.54 x 3/2 = 5.31 moles
Step 3 : find mass of CO
mass = moles × molar mass
from periodic table the molar mass of Co = 12+16 = 28 g/mol
mass is therefore = 5.31 moles × 28 g/mol = 148.68 grams
Substances a and b are both volatile liquids with p*a = 300 torr, p*b = 250 torr, and kb = 200 torr (concentration expressed in mole fraction). when xa = 0.9, bb = 2.22 mol kg−1, pa = 250 torr, and pb = 25 torr. calculate the activities and activity coefficients of a and
b. use the mole fraction, raoult's law basis system for a and the henry's law basis system (both mole fractions and molalities) for
b.
Use Raoult's Law and Henry's Law to calculate the activities and activity coefficients of substances a and b
Explanation:To calculate the activities and activity coefficients of substances a and b, we can use Raoult's Law for substance a and Henry's Law for substance b.
The activity of substance a can be calculated using:
a = a/*a
The activity of substance b in terms of mole fraction can be calculated using:
b = b/*b
The activity coefficient of substance a can be calculated using:
a = a/Xa
The activity coefficient of substance b can be calculated using:
b = b/Xb
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How can two atoms of the same chemical element be different?
A.They may be different isotopes of the element. Each isotope of the same element has a different number of electrons.
B.They may be different isotopes of the element. Each isotope of the same element has a different number of neutrons.
C.They may be different allotropes of the element. Each allotrope of the same element has a different number of electrons.
D.They may be different allotropes of the element. Each allotrope of the same element has a different number of neutrons.
The answer is B as isotopes are different versions of the same chemical element containing the same amount of protons and electrons but different amounts of neutrons.
A hexagon can be used to represent the structure of cyclohexane. What does each side of the hexagon represent?
Answer:
Single bond between two carbon atoms.
Explanation:
Let us look at the structure of a hexagon for representation of cyclohexane.
Cyclohexane has six carbons and thus we can place each carbon at the vertices of the hexagon. Now the bond joining each adjacent carbon atoms will be shown by the each side of the hexagon.
The hydrogen atoms are not shown in the structure.
Answer:
Single bond between two carbon atoms.
Explanation:
1. A student represented a water molecule using beads and straws. She connected two black beads and one white bead in a certain manner using straws. Which of the following explains the type of scientific model created by the student?
A. A simulation because it helps visualize the shape of the molecule.
B. A 3-dimensional model because it helps visualize the shape of the molecule.
C. A simulation because it helps understand the movement of atoms in the molecule.
D. A 3-dimensional model because it helps understand the movement of atoms in the molecule.
Answer: Option (b) is the correct answer.
Explanation:
When the student is using beads then he is representing atoms and the straws represent the bond between the atoms.
Therefore, when a model is represented by the given manner then it helps in identifying the geometry or shape of the object. This is because it shows how atoms are arranged in space along with their angle.
Therefore, we can conclude that out of the given options the type of scientific model created by the student is a 3-dimensional model because it helps visualize the shape of the molecule.
The type of scientific model created by the student has been the 3-D model for the visualization of shape. Thus, option B is correct.
The water molecule has been the simplest compound that has been consisted of the two hydrogen atoms bonded with an oxygen atom.
The presence of loan pairs to the oxygen atom has been responsible for the distortion in the linear shape, and the molecule has been present in the inverted geometry.
The model prepared by the student has black beads as the representation of the hydrogen atoms, while white beads as the representation of the oxygen atom. The straws have been the representation of the bonds in the structure.
The model prepared has been capable of demonstrating the arrangement of the elements in the 3-D plane and has been able to elucidate the structure of the molecule. Thus, option B is correct.
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Which metal is the best choice for recovering copper (reacting with copper) from the solution? Fe, Ag, Zn, or Al
Answer: The correct option is Aluminium.
Explanation: To recover copper from the solution, we require a metal which can easily displace copper from the solution.
The reactions in which metal displaces another metal in a chemical reaction are known as single displacement reactions. These reactions are studied using reactivity series.
[tex]A+BC\rightarrow AC+B[/tex]
A is more reactive than B.
The metal which lie above in the reactivity series will easily displace the metal which lies below in the reactivity series.
From the given options, Aluminium is the most reactive of all the metals and hence, it is the best choice for recovering copper from its solution.
For the unbalanced equation, what is the coefficient for C5H10? ? C5H10 (l) +? O2 (g) →? CO2 (g) +? H2O (g) A. 2 B. 4 C. 10 D. 6 E. 1
1C5H10 + 15/2O2 => 5CO2 + 5H2O
Explanation:
Balanced equation is defined as the equation which contains same number of atoms on both reactant and product side.
For example, [tex]C_{5}H_{10}(l) + O_{2} \rightarrow CO_{2}(g) + H_{2}O(g)[/tex]
Number of atoms on reactant side are as follows.
C = 5H = 10O = 2Number of atoms on product side are as follows.
C = 1H = 2O = 3So, to balance this equation we will multiply [tex]CO_{2}[/tex] on product side by 5 and also multiply [tex]H_{2}O[/tex] by 5. On the reactant side, we multiply [tex]O_{2}[/tex] by [tex]\frac{15}{2}[/tex]. Therefore, the balanced equation is as follows.
[tex]C_{5}H_{10}(l) + \frac{15}{2}O_{2} \rightarrow 5CO_{2}(g) + 5H_{2}O(g)[/tex]
Thus, we can conclude that for the given unbalanced equation the coefficient for [tex]C_5H_10[/tex] is 1.
For which of the following conversions does the value of the conversion factor depend upon the formula of the substance?
A) moles of any substance to number of particles
B) volume of gas (STP) to moles
C) mass of any substance to moles
D) density of gas (STP) to molar mass
For which of the following conversions does the value of the conversion factor depend upon the formula of the substance?
The answer is C
The answer is: C) mass of any substance to moles.
To converte mass to amount of substances, mass must be divided by molar mass (n = m ÷ M).
Molar mass M represent the mass of a substance divided by the amount of substance. If the formula is not correct, amount of substance is not correct.
For example, calculate molar mass of iron(II) chloride:
Atomic mass of iron is 55.8 g/mol.
Atomic mass of chlorine is 35.5 g/mol.
If compound is FeCl, molar mass would be 55,8 g/mol + 35,5 g/mol = 91,3 g/mlo, that is not correct.
If compound is FeCl₂, malar mass of compound would be:
55,8 g/mol + 2·35,5 g/mol = 126,8 g/mol, that is correct.
PLEASE HELP! 25 POINTS!!!! I got the #1, just not #2 and #3. An industrial chemical company has opened a new plant that will produce ammonia (NH3). Hydrogen and nitrogen gases are reacted to produce the ammonia. For the first batch of ammonia production, 475 g of nitrogen is reacted with excess hydrogen, and 397 g of ammonia are produced.
• Write the balanced equation for the formation of ammonia from hydrogen and nitrogen.
3H2+N2-->2NH3
• Calculate the theoretical yield of ammonia. Work must be shown to earn credit.
• Calculate the percent yield for the ammonia production. Work must be shown to earn credit.
Answer :
Part (a) : [tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Part (b) : Theoretical yield of [tex]NH_3[/tex] = 440.96 g
Part (c) : Percentage yield of ammonia is 90.03 %
Mass of [tex]N_2[/tex] = 475 g
Molar mass of [tex]N_2[/tex] = 28 g/mole
Molar mass of [tex]NH_3[/tex] = 17 g/mole
Experimental yield of [tex]NH_3[/tex] = 397 g
Part (a) :The balanced chemical reaction will be:
[tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Part (b) :To calculate the moles of [tex]N_2[/tex]:
[tex]\text{Moles of }N_2=\frac{\text {Mass of }N_2}{\text{ Molecular mass of }N_2}=\frac{475g}{28g/mole}=16.96moles[/tex]
From the given balanced equation:
1 mole of [tex]N_2[/tex] gas produces 2 moles of [tex]NH_3[/tex]
16.96 moles of [tex]N_2[/tex] gas produces [tex]\frac{2}{1}\times 16.96=33.92[/tex] moles of [tex]NH_3[/tex]
Now we have to calculate the mass of [tex]NH_3[/tex]
[tex]\text{ Mass of }NH_3=\text {Moles of }NH_3\times \text{ Molar mass of }NH_3[/tex]
[tex]\text{ Mass of }NH_3=(33.92moles)\times (17g/mole)=440.96g[/tex]
Therefore, the theoretical yield of [tex]NH_3[/tex] gas = 440.96 g
Part (c) : Percentage yield :
[tex]\% \text{ yield of }NH_3=\frac{\text {Experimental yield of NH_3}}\text {Theoretical yield of }NH_3\times 100[/tex]
[tex]\% \text{ yield of }NH_3=\frac{397g}{440.96g}\times 100=90.03\%[/tex]
Therefore, the % yield of ammonia is 90.03 %
Circle three objects. Describe two forms of energy each object has. Force and Energy page 118.
Here is the answer!!! Just fill in the blanks.
of the following is a force acting between objects that do not touch? (3 points)
Normal force
Frictional force
Electrical force
Applied force
why do comets have tails
As a comet approaches the Sun, it starts to heat up. The ice transforms directly from a solid to a vapor, releasing the dust particles embedded inside. Sunlight and the stream of charged particles flowing from the Sun – the solar wind – sweeps the evaporated material and dust back in a long tail.
Answer:
Comets are composed of ice, dust and frozen gases. The core of the comet is known as nucleus which is formed of rocks and frozen gases. Coma is the atmosphere of the comet. As the comet enters the inner solar system, the coma expands due to sublimation of frozen gases. As it nears the sun, the coma extends backwards and forms a long tail. It extends backwards due to the solar wind. The charged particles from the sun take away the evaporated material and dust of the comet backwards forming tail.
The ratio between the force of sliding friction and the normal force of an object is called _____.
A.rolling friction
B.the drag
C.the coefficient of friction
D.the starting friction
Answer: The correct answer is C.
Explanation: Frictional force is the contact force which resists the motion of one surface on another.
Mathematically,
[tex]f=\mu N[/tex]
where,
f = frictional force
[tex]\mu[/tex] = Coefficient of friction
N = normal force acting on a body
We need to find the ratio of force of sliding friction ( which is a type of frictional force) and the normal force acting on an object. This will be equal to coefficient of friction.
[tex]\mu=\frac{f}{N}[/tex]
Given a formula for oxygen: What is the total number of electrons shared between the atoms represented in this formula
Answer is: the total number of electrons shared between the atoms is four.
Molecule of oxygen is nonpolar because double linear bonds (O=O).
Oxygen (O) is an element with atomic number 8, it means it has eight protons and eight electrons, so atom has neutral charge. Oxygen is a nonmetal.
Electron configuration of oxygen atom: ₈O 1s² 2s² 2p⁴.
Oxygen atom has six valence electrons, so it is in 16 group of Periodic table of elements.
Two valence electrons from both oxygen atoms form double bond (O::O) at oxygen molecule.
Answer:
Formula for oxygen is [tex]O_{2}[/tex] and total number of electrons shared between the atoms are 4
Explanation:
Oxygen is a diatomic molecule. Hence two oxygen atoms combine to produce one oxygen molecule.
Now, number of valence electron in a oxygen atom is 6. So total number of valence electrons used to form oxygen molecule are 12.
To draw a Lewis structure for [tex]O_{2}[/tex], octet rule should be fulfilled by both oxygen atoms.
According to octet rule, an atom should have 8 electrons in its valence shell
Lewis structure for oxygen molecule has been attached below.
Here electrons shared by oxygen atoms are represented as vertical line. These are called bonding electrons.
Unshared electrons are represented by dot. These are called lone pairs.
Here one bond is formed by sharing two electrons.
As there are two bonds between two oxygen atoms therefore total number of shared electrons between oxygen atoms are 4.
Given: CH4 + 2O2 → CO2 + 2H2O In the chemical reaction, if 10 moles of H2O are produced, ____ moles of CO2 are also produced.
Answer: 5 moles of [tex]CO_2[/tex] will be produced when 10 moles of [tex]H_2O[/tex] are produced.
Explanation:
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
Multiplying the chemical equation with 5.
[tex]5CH_4+10O_2\rightarrow 5CO_2+10H_2O[/tex]
In the given reaction ,if 10 moles of water are produced then 5 moles of Carbon-dioxide produced.
Answer:
5
Explanation:
the phase change that is reverse of evaporation is
Condensation is the reverse change of evaporation.
The phase that is the reverse of evaporation is Condensation.
It is the process by which gas is cooled to any temperature above it freezing point to make it into liquid form.
A 0.3000-g sample of soda ash (which contains sodium carbonate) is dissolved in 50.00 mL of water. Titration with standard 0.1000 M HCl required 42.70 mL of the acid to neutralize the soda ash solution. What is the percent by mass of sodium carbonate in the soda ash sample? The molar mass of sodium carbonate is 105.99 g/mol. The equation for the reaction of sodium carbonate and hydrochloric acid is
As a cooking method, braising is valued for its A. ability to retain flavor. B. quickness and convenience. C. ability to create delicate flavors. D. simplicity and versatility.
Answer: Option (A) is the correct answer.
Explanation:
Braising means first of all fry a dish slightly and then cook it slowly in a closed vessel or dish. The vessel is close so that the liquid present inside it does not evaporates.
Also, Braising is done to mix the flavors of different liquids or spices appropriately.
Thus, we can conclude that as a cooking method, braising is valued for its ability to retain flavor.
Answer:
The correct answer is D.
Explanation:
This method of cooking is economical because it allows the use of common cuts, it is efficient because it allows to prepare the food in a single pot. The preparation is simple as it does not require an elaborate preparation. The meat is cooked in a pot, seasoned from the beginning, and there is no need to intervene in the process.
Have a nice day!
During chemistry, Dan mixes two clear, colorless solution and mixing them produces a yellow precipitate in a clear, colorless final solution as shown by the chemical equation.
Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq)
What physical evidence indicates that there has been a chemical reaction?
Answer: Formation of precipitate indicates that there has been a chemical reaction.
Explanation:
Chemical reaction: It is defined as change in arrangement of the atoms so as to form a new substance.
Mixing of two clear solutions that is lead nitrate and potassium iodide gives out yellow solid precipitate of lead iodide with aqueous solution of potassium nitrate.
[tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]
The physical evidence which indicates that chemical reaction has been taken place is formation of yellow solid precipitate of lead iodide ,([tex]PbI_2[/tex]).