To measure the reaction heat more accurately at isobaric condition, we can add a lid to the calorimeter to prevent heat loss due to evaporation.
Thus, to measure the reaction heat more accurately at isobaric condition, some certain modifications can be made to the coffee cup calorimeter which includes adding a lid to the calorimeter to prevent heat loss due to evaporation to keep the pressure inside the calorimeter constant.
Using a magnetic stir bar to ensure even mixing of the reactants to ensure the accurate temperature readings, use of thermometer with a smaller stem to reduce the amount of heat transferred from the solution to the thermometer, etc. are some other modifications that can be made on the coffee cup calorimeter to measure the reaction heat more accurately at isobaric condition.
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This weather map showed the temperature (in °F) in the United States on a winter day. It also includes two pressure systems, labeled "H" and "L." Explain where weather fronts are most likely located, and predict the weather at each pressure system. edmentum science
Answer:
"H"is in California (High pressure cell brings cool conditions )it would be cool and the fronts are located on the coast of California."L"is in Utah (Low pressure cell brings warm conditions) it would be warmer. you let me know. I answeredit all the way.
shapes of simple polyatomic molecules
Answer:
Polyatomic molecules that are linear in shape are known as linear polyatomic molecules. The atoms in these linear molecules are arranged in a straight line (at an angle of 180 degrees). At the central atom of linear geometry polyatomic molecules, the electron pair has sp hybridization.
How many moles of KF are contained in 180.0 mL of a 0.250 M solution?
Answer:
To calculate the number of moles of KF in a solution, we can use the formula:
moles = concentration x volume
where concentration is in units of moles per liter (M), and volume is in liters (L).
First, we need to convert the volume from milliliters (mL) to liters (L):
180.0 mL = 0.1800 L
Next, we can plug in the values we have:
moles = 0.250 M x 0.1800 L = 0.0450 moles
Therefore, there are 0.0450 moles of KF in 180.0 mL of a 0.250 M solution.
Explanation:
Substance A decomposes at a rate proportional to the amount of A present.
Write an equation relating A to the amount left of an initial amount Ao after time t.
It is found that 8 g of A will reduce to 4 g in 3 hr. After how long will there be only 1 g left?
It will take approximately 2.079 hours for there to be only 1 g of substance A left.
The rate of decomposition of substance A is proportional to the amount of A present, which means that we can use the following differential equation to describe the decay;
dA/dt = -kA
where A is the amount of substance A at time t, k is the rate constant of the reaction, and the negative sign indicates that A is decreasing over time.
To solve differential equation, we separate the variables and integrate;
[tex]d_{A}[/tex]/A = -k [tex]d_{t}[/tex]
Integrating both sides gives;
ln(A) = [tex]-k_{t}[/tex] + C
where C is the constant of integration. To find the value of C, we can use the initial condition that 8 g of A reduces to 4 g in 3 hours. At t=0, A=Ao=8 g, and at t=3, A=4 g. Substituting values into the equation above, we have;
ln(8) = -3k + C
ln(4) = -6k + C
Subtracting first equation from second, we get;
ln(4/8) = -3k
Simplifying, we get;
k = ln(2)/3
Now, we can use the equation we derived earlier to find how long it will take for there to be only 1 g of A left;
ln(A) =[tex]-k_{t}[/tex] + C
ln(1) = -(ln(2)/3)t + C
Simplifying, we get:
t = 3 ln(2)
t ≈ 2.079 hours
Therefore, it will take 2.079 hours.
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Which compound represents fe+3 o-2
Answer:
The compound that represents Fe+3 O-2 is Fe2O3 (iron oxide or rust)
a 70 piece of metal at 120 C is dropped into a kilometer with 150 g of 30C water the final temperature of the water and little changes 35c what is the specific heat of the metal
A 70 piece of metal at 120 C is dropped into a kilometer with 150 g of 30C water the final temperature of the water and little changes 35c, 0.385 J/g°c is the specific heat of the metal.
The amount of heat needed to raise a substance's temperature by one degree Celsius in one gramme, also known as specific heat. Typically, calories and joules per gramme per degree Celsius are used as a measure of specific heat.
In the 18th century, the Scottish researcher Joseph Black found that equivalent masses of various substances required varying quantities of heat to bring them across the same temperature range. Based on this finding.
cm = (0.15 kg x 4.18 J/gCx (35C - 30C)) / (70 pieces x 0.1 kg/piece x (120C - 35C))
cm = 0.385 J/g°c
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A small sample of lead 5g (c=0.138 J/g°C) is placed into 50g of water at 25°C. What is the system’s final temperature if lead started at 50°C?
The system's final temperature is 25.825°C.
To solve this problem, we need to use the equation:
q = m × c × ΔT
where q is the heat absorbed or released, m is the mass of the substance, c is the specific heat capacity of the substance, and ΔT is the change in temperature.
In this case, the lead is losing heat to the water, so q will be negative. The water is gaining heat from the lead, so q will be positive.
First, let's calculate the amount of heat lost by the lead:
q_lead = -m_lead × c_lead × ΔT_lead
= -5 g × 0.138 J/g°C × (50°C - 25°C)
= -172.5 J
Next, let's calculate the amount of heat gained by the water :
[tex]q_{water}[/tex] = [tex]m_{water}[/tex] × [tex]c_{water}[/tex] × Δ[tex]T_{water}[/tex]
= 50 g × 4.184 J/g°C × ([tex]T_{f}[/tex] - 25°C)
where [tex]T_{f}[/tex] is the final temperature of the water
Since the total amount of heat lost by the lead is equal to the total amount of heat gained by the water (assuming no heat is lost to the surroundings), we can set [tex]q_{lead}[/tex] equal to [tex]q_{water}[/tex] and solve for [tex]T_{f}[/tex]:
- [tex]q_{lead}[/tex] = [tex]q_{water}[/tex]
172.5 J = 50 g * 4.184 J/g°C * ([tex]T_{f}[/tex] - 25°C)
[tex]T_{f}[/tex]- 25°C = 0.825
[tex]T_{f}[/tex] = 25°C + 0.825
[tex]T_{f}[/tex] = 25.825°C
Therefore, the system's final temperature is 25.825°C.
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The symbol that indicates a substance dissolve in water is
The symbol that indicates a substance dissolve in water is (aq).
What is the symbol?The word "(aq)" stands for aqueous and denotes a material that dissolves in water.
Aqueous solutions are created when substances dissolve in water and are uniformly dispersed throughout the liquid. "(aq)" is added to the end of a substance's chemical formula in a chemical equation to denote that the material is in an aqueous state.
We often see this in several chemical reactions and the symbols shows that the solute was dissolved in water.
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N₂ +
H₂O →>>
NH, -
+
0₂
The balanced chemical equation for the reaction is:
N₂ + 3H₂O → 2NH₃ + O₂
The equation shows that nitrogen gas (N₂) and water (H₂O) react to form ammonia (NH₃) and oxygen gas (O₂). The coefficients in the balanced equation indicate that one molecule of N₂ reacts with three molecules of H₂O to produce two molecules of NH₃ and one molecule of O₂.
Pls answer these 9 questions I’ll mark the brainliest
1. Gases can be changed into liquids by _____.
A. adding heat
B. removing heat
C. none of the above
2. Which of the following is a true statement?
A. Smashing an object into many pieces changes its chemical composition.
B. Smashing an object into many pieces is a chemical change.
C. Smashing an object into many pieces does not change the object.
D. Smashing an object into many pieces is a physical change.
3.Match the physical forms of matter with their descriptions.
1. no fixed volume or shape _______liquid
2. fixed volume and shape _____solid
3. fixed volume but no fixed shape. _____gas
4. Which of the following is a true statement?
A. Melting is a biological change.
B. Melting is a chemical change.
C. Melting is a physical change.
D. Melting is a change made by humans.
5. How do substances differ after a chemical change?
A. The new substance is the same as the beginning substance.
B. The new substance is different from the beginning substance.
C. The new substance may or may not be the same as the beginning substance.
6. What factor is mostly responsible for the form of matter?
A.temperature
B.pressure
C.weather
D.time
7. Which of the following is a false statement?
A. solid substances need different temperatures to melt them.
B. All solid substances require the same temperature to melt them.
C. Heat is sometimes necessary to change physical property of an object.
8. Which of the following is a chemical change?
A. ice melting into water
B.an object broken into pieces
C.paper burning into ash
D.water changing to steam
9. When does heat produce a chemical change?
A.when heat energy is transferred
B.when heat changes ice into liquid water
C.when heat changes the chemical composition of an object
D.when heat is observed in an experiment
Answer:
below
Explanation:
1. B. removing heat.
The process of changing a gas into a liquid is called condensation. It occurs when the gas loses heat energy and its particles slow down and come closer together, eventually forming a liquid. Therefore, by removing heat from a gas, it can be changed into a liquid.
2. D. Smashing an object into many pieces is a physical change.
Smashing an object into many pieces does not change the chemical composition of the object. It only changes its physical appearance or state. A physical change is a change in the state or appearance of matter without any change in its chemical composition. Therefore, smashing an object into many pieces is a physical change.
3. No fixed volume or shape: gas
Fixed volume and shape: solid
Fixed volume but no fixed shape : liquid
4. C. Melting is a physical change.
Melting is the process of changing a solid substance into a liquid by heating it to its melting point. During this process, there is no change in the chemical composition of the substance, only a change in its physical state from solid to liquid. Therefore, melting is a physical change.Option A is incorrect because melting does not involve any biological process.
Option B is incorrect because melting does not result in any chemical reaction that alters the composition of the substance.
Option D is incorrect because melting is a natural physical phenomenon that occurs due to changes in temperature or pressure.
5. B. The new substance is different from the beginning substance.
In a chemical change, a chemical reaction occurs, which involves the breaking and formation of chemical bonds between atoms or molecules. This results in the formation of one or more new substances with different chemical properties than the original substances.
During a chemical change, the original substances are converted into new substances that have different physical and chemical properties, such as color, texture, odor, melting and boiling points, solubility, reactivity, etc. Therefore, the new substance is different from the beginning substance.
6. A. Temperature.
Temperature is the primary factor responsible for the form of matter. At different temperatures, matter exists in different states:
- At low temperatures, matter exists as a solid because the particles are tightly packed and have low energy, which keeps them in a fixed position.
- At higher temperatures, matter exists as a liquid because the particles have enough energy to move past each other but are still close together.
- At even higher temperatures, matter exists as a gas because the particles have enough energy to overcome the attractive forces between them and move independently.
Pressure can also influence the form of matter, but temperature is the primary factor that determines the state of matter. Weather and time are not factors that directly influence the form of matter.
7. B. All solid substances require the same temperature to melt them.
This statement is false. Different solid substances have different melting points, which is the temperature at which they change from a solid to a liquid. The melting point depends on the chemical composition and structure of the substance. Therefore, different solid substances require different temperatures to melt them.
Option A is a true statement because different solid substances have different melting points.
Option C is a true statement because heat can be used to change the physical property of an object, such as melting or boiling it.
8. C. Paper burning into ash.
This is a chemical change because burning paper involves a chemical reaction in which the cellulose fibers in paper combine with oxygen in the air to form new substances, such as water vapor, carbon dioxide, and ash. The chemical composition of the paper changes, and it cannot be reversed.
Option A is a physical change because melting ice into water involves only a change in physical state, not a change in chemical composition.
Option B is a physical change because breaking an object into pieces only changes its physical appearance, not its chemical composition.
Option D is a physical change because water changing to steam involves only a change in physical state, not a change in chemical composition.
9. C. When heat changes the chemical composition of an object.
Heat can produce a chemical change when it is used to break or form chemical bonds between atoms or molecules, resulting in a change in the chemical composition of the substance. This can lead to the formation of new substances with different chemical properties than the original substance. Therefore, option C is the correct statement.
Option A is incorrect because heat energy transfer can produce a physical change, such as melting or boiling, but not necessarily a chemical change.
Option B is incorrect because heat changing ice into liquid water is a physical change, not a chemical change.
Option D is incorrect because observing heat in an experiment does not necessarily produce a chemical change.
precipitation of carbonate ion with barium ion
Answer:
When barium ions are added to a solution containing carbonate ions, barium carbonate precipitate is formed, which serves as an additional confirmation for the presence of carbonate ions in the medium. According to Table 1, silver salts of chloride ions are insoluble.
Including the cis or trans designation, what is the IUPAC name of the following substance?
It is not necessary to put cis or trans in italics.
CH3CH2 CH3
\c=c/
/ \
CH3 H
The IUPAC name of the given substance is (Z)-3-methyl-2-pentene.
The (Z) indicates that the two methyl groups on the double bond are on the same side of the bond, which is cis-configuration. The longest carbon chain in the molecule is five carbons, so it is named as pentene. The double bond is located between the second and third carbon atoms, so it is named as 2-pentene. Since the methyl group is attached to the third carbon atom, it is named as 3-methyl-2-pentene.
The prefix "Z" is used to indicate the cis-configuration of the molecule, where the two substituents on the double bond are on the same side. This nomenclature is important in identifying and describing the structure of organic compounds, particularly in fields such as biochemistry and medicinal chemistry where the structure of molecules plays a crucial role in their function.
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HELP PLEASE!! DUE IN A FEW MINUTES!!
1) Aluminum and indium are in the same group
2) Barium is in group 2 and period 6
What is the periodic table?The names of the compounds are;
Triphosphorous tetrachloride
Calcium bromide
Nitrogen hexasulfur
The molecules that balance the charges are;
K3P, Al2O3, CaS
The elements in group 17 are chlorine and fluorine
The elements in period 3 are sodium and magnesium.
The balanced equations are from the data given;
SnO2 + 2H2 → Sn + 2H2O
4Al + 3O2 → 2Al2O3
Au2S3 + 3H2 → 2Au + 3H2S
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Heat absorbed or released by a substance can be calculated with the equation _____________.
q = m × Cs × ∆T
q = m × Cs ÷ ∆T
q = m + Cs + ∆T
q = m + Cs
At 2000 ∘c the equilibrium constant for the reaction 2no(g)⇌n2(g)+o2(g) is kc=2.4×103. You may want to reference (pages 641 - 644) section 15.6 while completing this problem. Part a if the initial concentration of no is 0.175 m, what is the equilibrium concentration of no? how is the quadratic equation set up i cannot get the right values
A rubber balloon containing 1.0 L of gas is carried from the top of a mountain to the bottom of the mountain, where it’s volume is measured as .85 L at standard pressure. Assuming that there was no temperature change during the trip, what was the pressure in atmospheres at the top of the mountain?
Show steps pls
Answer:
the pressure at the top of the mountain was 0.85 atm.
Explanation:
We can use the combined gas law to solve this problem:
(P1 * V1) / (T1) = (P2 * V2) / (T2)
where P1, V1, and T1 are the initial pressure, volume, and temperature, and P2, V2, and T2 are the final pressure, volume, and temperature.
Assuming that the temperature remains constant, we can simplify the combined gas law to:
P1 * V1 = P2 * V2
where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume.
Substituting the given values, we get:
P1 * 1.0 L = 1 atm * 0.85 L
P1 = (1 atm * 0.85 L) / 1.0 L
P1 = 0.85 atm
Reversible reactions allow products to create the reactants after a chemical reaction has gone from reactants to products. Which of the following is an example of a reversible reaction?
A) Oxygen combining with hemoglobin in red blood cells in our body, and then the red blood cells delivering the oxygen to needed locations\
B) Ammonium chloride separating into ammonia and hydrogen chloride gas
C)Hydrogen and oxygen combining to form water, and then water being broken down by a cell to be used in cellular respiration
D)All of the above
Question 3 of 10
How can the effect of heat on a reaction be determined?
A. Heat will increase reaction rate, but not equilibrium position.
B. Heat always shifts a reaction toward reactant formation.
C. Heat always shifts a reaction toward product formation.
D. Heat is treated as a reactant or a product.
SUBMIT
How much energy is required to heat 192 grams of lead from 18 degrees Celsius to 44
degrees Celsius?
The amount of energy required to heat the given amount of lead from 18°C to 44°C is 638.976 J.
The specific heat capacity of lead is 0.128 J/g°C.
To calculate the amount of heat energy required to heat 192 grams of lead from 18°C to 44°C, we can use the formula:
Q = m × c × ΔT
where:
Q = heat energy (in Joules)
m = mass of the substance (in grams)
c = specific heat capacity of the substance (in J/g°C)
ΔT = change in temperature (in °C)
Plugging in the given values:
m = 192 g
c = 0.128 J/g°C
ΔT = (44°C - 18°C) = 26°C
Q = 192 g × 0.128 J/g°C × 26°C
Q = 638.976 J
So, the amount of heat energy required to heat 192 grams of lead from 18°C to 44°C is 638.976 Joules.
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Calculate the final temperature (in Celsius) of HCI gas if 0.500 L at 42°C and 0.950 atm is heated
until the volume reaches 1.81 L at 0.950 atm. (deg C)
Please name this compound.
Answer:
The chemical name for this compound is 4-ethyl-2-methylhex-2-ene.
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The nitrogen pressure at the Venusian surface is 2050 torr and the atmosphere of Venus is 3.0 mole% N2. What is the surface pressure on Venus in atm?
Determine the total pressure of a gas mixture that contains O
To determine the total pressure of a gas mixture that contains oxygen (O2), you need to know the partial pressure of the oxygen gas and the partial pressures of the other gases in the mixture. The total pressure of a gas mixture is equal to the sum of the partial pressures of all the gases in the mixture. This is known as Dalton’s Law of Partial Pressures. Can you provide more information about the gas mixture, such as the partial pressures or mole fractions of the gases in the mixture?
MARK ME BRAINLEISThow mony moles of each ion present in 100mL of0.12M Ca3(Po4)2 solution.
In 100 mL of 0.12 M Ca3(PO4)2 solution, there are 0.036 moles of calcium ions and 0.024 moles of phosphate ions.
To find the number of moles of each ion present in 100 mL of 0.12 M Ca3(PO4)2 solution, we first need to determine the formula weight of Ca3(PO4)2.
Ca3(PO4)2 contains three calcium ions (Ca2+) and two phosphate ions (PO43-).
The atomic weight of calcium (Ca) is 40.08 g/mol, and there are three calcium ions in Ca3(PO4)2, so the total weight of calcium in Ca3(PO4)2 is 3 x 40.08 = 120.24 g/mol.
The atomic weight of phosphorus (P) is 30.97 g/mol, and the atomic weight of oxygen (O) is 16.00 g/mol.
The molecular weight of the phosphate ion (PO43-) is therefore 30.97 + (4 x 16.00) = 94.97 g/mol. Since there are two phosphate ions in Ca3(PO4)2, the total weight of phosphate in Ca3(PO4)2 is 2 x 94.97 = 189.94 g/mol.
The total formula weight of Ca3(PO4)2 is therefore 120.24 + 189.94 = 310.18 g/mol.
To find the number of moles of each ion present in 100 mL of 0.12 M Ca3(PO4)2 solution, we can use the formula:
moles = concentration x volume
For calcium ions:
moles of Ca2+ = concentration of Ca3(PO4)2 x (3 moles of Ca2+ / 1 mole of Ca3(PO4)2) x volume
moles of Ca2+ = 0.12 M x (3 / 1) x 0.1 L
moles of Ca2+ = 0.036 mol
For phosphate ions:
moles of PO43- = concentration of Ca3(PO4)2 x (2 moles of PO43- / 1 mole of Ca3(PO4)2) x volume
moles of PO43- = 0.12 M x (2 / 1) x 0.1 L
moles of PO43- = 0.024 mol
Therefore, in 100 mL of 0.12 M Ca3(PO4)2 solution, there are 0.036 moles of calcium ions and 0.024 moles of phosphate ions.
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concept of hybridization in chemistry
Answer:
Hybridization is the process in which two complementary single-stranded DNA and/or RNA molecules bond together to form a double-stranded molecule.
Explanation: Hope it helps you:)))))
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one of the compounds left a white solid in the paper What is the name of thus compound?
One of the compounds left a white solid in the filter paper . Fat is the name of this compound.
Fat is typically defined as any ester of fatty acids, or a combination of such compounds, most frequently those that occur in living things or in food, in the fields of nutrition, biology, and chemistry. Triglycerides, or triple esters of glycerol, are the primary constituents of vegetable oils including fatty tissue in animals. The term is frequently used to refer particularly to triglycerides.
The word may additionally be employed more broadly to refer to any biologically relevant compound made of carbon, hydrogen, and oxygen that is soluble to non-polar solvents but insoluble in water. One of the compounds left a white solid in the filter paper . Fat is the name of this compound.
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Hydrazine, N2H4, reacts with oxygen to form nitrogen gas and water.
N2H4(aq)+O2(g)⟶N2(g)+2H2O(l)
If 3.45 g of N2H4 reacts with excess oxygen and produces 0.650 L of N2, at 295 K
and 1.00 atm, what is the percent yield of the reaction?
Four peripheral hydrogen atoms and two singly-bonded nitrogen atoms make up the molecule of hydrazine.
Thus, It is a colourless, poisonous irritant and sensitizer in its anhydrous form, which harms the central nervous system and causes symptoms as severe as tumours and convulsions.
In addition to having a strong reducing agent that makes it highly explosive, hydrazine has a strong smell that is similar to that of ammonia.
Given this, it appears odd that over 100,000 metric tonnes of the substance are produced annually throughout the world. But hydrazine does have an impact on our daily activities. It can save our lives, give us food and clothing, keep us warm, and even transport us to the moon. It even has the ability to go back in time.
Thus, Four peripheral hydrogen atoms and two singly-bonded nitrogen atoms make up the molecule of hydrazine.
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A substance with a pH of 2 would be considered a strong what?
Answer:
A substance with pH 2 should be considered a strong acid.
Explanation
ph is a measure of how acidic or basic water is. The range goes from 0-14, with 7 being neutral.
pH of less than 7 indicate acidity and pH greater than 7 indicates base. So , the intensity of the acidic products increase as the pH decrease from 6 to 0 ,i.e. lower the value of pH higher will be the acidity.
With pH 2 given in the question it is considered as a strong acid.However , pH 2 acids are less acidic than acids having pH 0 and 1 but more acidic in compare to pH 3-6.
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2.5 mL of a 0.150 M solution is diluted with 2.5 mL of water. What is the concentration of the new solution?
The new concentration of the solution can be gotten as 0.075 M.
Dilution formula for solutionsThe formula that we should use is;
C1V1 = C2V2
where:
C1 = initial concentration of the solution (in units of mass/volume, moles/liter, or other concentration units)
V1 = initial volume of the solution
C2 = final concentration of the solution after dilution
V2 = final volume of the solution after dilution
We have to note that;
C1V1= C2V2
Thus we have that;
2.5 * 0.150 = 5 * V
V = 0.075 M
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You have 400,000 atoms of a radioactive substance. After 2 half-lives have past, how many atoms remain?
Remember that you cannot have a fraction of an atom, so round the answer to the nearest whole number.
After 2 half-lives, 100,000 atoms of the radioactive substance will remain.
If two half-lives have passed, the number of remaining atoms will be one-fourth (1/2 x 1/2 = 1/4) of the original number of atoms.
Therefore, the number of remaining atoms will be:
400,000 x (1/4) = 100,000 atoms
Rounding this to the nearest whole number, we get:
100,000 atoms
Therefore after 2 half-lives, 100,000 atoms of the radioactive substance will remain.
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