Answer:
1.7 × 10⁴ J
Explanation:
Step 1: Calculate the heat required to raise the temperature of ice from -15 °C to 0°C
We will use the following expression.
Q₁ = c(ice) × m × ΔT
Q₁ = 2.03 J/g.°C × 25 g × [0°C - (-15°C)] = 7.6 × 10² J
Step 2: Calculate the heat required to melt 25 g of ice
We will use the following expression.
Q₂ = C(fusion) × m
Q₂ = 80. cal/g × 25 g × 4.184 J/1 cal = 8.4 × 10³ J
Step 3: Calculate the heat required to raise the temperature of water from 0°C to 75 °C
We will use the following expression.
Q₃ = c(water) × m × ΔT
Q₃ = 4.184 J/g.°C × 25 g × (75°C - 0°C) = 7.8 × 10³ J
Step 4: Calculate the total heat required
Q = Q₁ + Q₂ + Q₃
Q = 7.6 × 10² J + 8.4 × 10³ J + 7.8 × 10³ J = 1.7 × 10⁴ J
What is the most likely charge on an ion formed by an element with a valence electron configuration of ns2np4
Answer:
2-
Explanation:
For an element to be stable, it must follow the octet rule: an atom will gain, lose or share electrons until its valence shell is complete with 8 electrons.
An element with the valence electron configuration ns²np⁴ has 6 (2+4) electrons in its valence shell. Thus, in order to fulfill the octet, it will gain 2 electrons. As a consequence, it will form an anion with charge 2-.
Question 8 of 24
Which statement best describes the intermolecular forces between H2 molecules and H2O molecules in the gas phase?
A. There is hydrogen bonding between H2 molecules and between H2O molecules.
B. There are no forces between H2 molecules or between H20 molecules.
C. There are no forces between H, molecules, and there is hydrogen bonding between the H20 molecules.
D. There are Van der Waals forces between both molecules and dipole-dipole forces between the water molecules.
help pleaseeee!!!!!
Answer:
it will be no. A that is thereis hydrogen bonding H2 molecules and between H2O molecules
jessica is a crime scene investigator studying a breech face mark where is the breech face mark located
Answer:
on the back of the firing pin
Explanation:
If you knew the volume of the solution containing NaCl(aq), determine how you would predict the mass of AlCl3(s) formed
Answer:
See explanation.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to realize that the NaCl solution must react with an aluminum-containing substance, say the hydroxide or any other salt, so that the following equation will take place:
[tex]3NaCl(aq)+Al^{3+}\rightarrow 3Na^+(aq)+AlCl_3(s)[/tex]
In such a way, given the volume of the NaCl solution, it must be necessary to know its concentration, in order to get moles of this salt, further use the 3:1 mole ratio of NaCl to AlCl3 and the molar mass of the latter (133.34 g/mol) in order to solve an stoichiometric setup like the following:
[tex]m_{AlCl_3}=V_{NaCl}*M_{NaCl}*\frac{1molAlCl_3}{3molNaCl} *\frac{133.34gAlCl_3}{1molAlCl_3}[/tex]
Besides, you must make sure the volume is in liters.
Best regards!
Acetylene (C2H2) gas is often used in welding torches because of the very high heat produced when it reacts with oxygen (O2) gas, producing carbon dioxide gas and water vapor. Calculate the moles of acetylene needed to produce 0.10 mol of carbon dioxide. Be sure your answer has a unit symbol
Answer:
0.05 mol
Explanation:
The balanced equation for the reaction that takes place is:
2C₂H₂ (g) + 5O₂ (g) → 4CO₂ (g) + 2H₂O (g)Now we convert 0.10 moles of carbon dioxide (CO₂) into moles of acetylene (C₂H₂), using the stoichiometric coefficients of the balanced reaction:
0.10 mol CO₂ * [tex]\frac{2molC_2H_2}{4molCO_2}[/tex] = 0.05 mol C₂H₂. 500 L of H2 and 400 L of O2 are mixed to produce H2O in a closed container. What volume
of H2O is produced ? Which is the limiting reagent ?
Answer:
may be 700Explanation : What i feel is that the chemical formula is 2 H2 + O2 — 2 H2O
So taking 500 as 2 H2 that the value of O2 reacted will be half of original value that is 200...
What is the mass of 6 atom(s) of copper in grams?
Answer:
6.33×10¯²² g
Explanation:
From the question given above, the following data were obtained:
Number of atoms = 6 atoms
Mass of copper (Cu) =?
From Avogadro's hypothesis, we understood that:
6.02×10²³ atoms = 1 mole of Cu
But 1 mole of Cu = 63.5 g
Thus,
6.02×10²³ atoms = 63.5 g of Cu
Finally, we shall determine the mass of 6 atoms of copper. This can be obtained as illustrated below:
6.02×10²³ atoms = 63.5 g of Cu
Therefore,
6 atoms = (6 × 63.5) / 6.02×10²³
6 atoms = 6.33×10¯²² g of Cu
Therefore, the mass of 6 atoms of copper is 6.33×10¯²² g.
The diagram shows an experiment. damp litmus paper gas given off mixture of ammonium chloride and sodium hydroxide 1 heat What is the name of the gas and the final colour of the litmus paper? gas colour A ammonia blue B ammonia red с chlorine white D chlorine red plz guys help me
Answer:
The correct answer is - A. ammonia blue.
Explanation:
It is given that there is a mixture of ammonium chloride and sodium hydroxide and if we heat the Mixture of NH4Cl and NaOH then, the following reaction will take place-
NH4Cl (aq)+ NaOH (aq)==> NaCl (aq) + NH3 (g)+ H2O (l)
In this reaction, there is a release of NH3 gas which is absorbed on litmus paper. We know that NH3 gas is basic in nature and so it will turn litmus paper blue.
Thus, the correct answer would be - NH3 (ammonia ) and Blue
NaCl and HCl both have chlorine but are different types of bonds.
What kind of bonds are each of these?
What evidence did you use to determine what types of bonds they are?
Answer:
In HCl ,bond between hydrogen and chlorine is covalent. But due to difference in electronegativity of hydrogen and chlorine,shared electron pair gets attracted towards chlorine. Due to this polar covalent
what's the formula of mercury (I) dioxonitrate III
Calculate the number of milliliters of 0.666 M Ba(OH)2 required to precipitate all of the Pb2 ions in 163 mL of 0.656 M Pb(NO3)2 solution as Pb(OH)2. The equation for the reaction is:
Pb(NO3)2(aq) Ba(OH)2(aq) Pb(OH)2(s) Ba(NO3)2(aq)
Answer:
161 mL
Explanation:
Pb(NO₃)₂(aq) + Ba(OH)₂(aq) → Pb(OH)₂(s) + Ba(NO₃)₂(aq)First we calculate how many Pb⁺² moles reacted, using the given concentration and volume of the Pb(NO₃)₂ solution:
163 mL * 0.656 M = 107 mmol Pb(NO₃)₂As 1 millimol of Pb(NO₃)₂ would react with 1 millimol of Ba(OH)₂, to precipitate 107 mmoles of Pb(NO₃)₂ we would require 107 mmoles of Ba(OH)₂.
Using the number of moles and the concentration we can calculate the required number of milliliters:
0.666 M = 107 mmol / x mLx mL = 161 mLThe density of water is about 1.0 g/mL at room temperature. Briefly explain how the density of an aqueous solution at room temperature can be significantly less than 1.0 g/mL. Give an example of such a solution.
Answer:
The density of water is about 1.0 g/mL at room temperature.
Briefly explain how the density of an aqueous solution at room temperature can be significantly less than 1.0 g/mL.
Give an example of such a solution.
Explanation:
That means 1.0mL of water weighs ---- 1.0g
If any other aqueous solution which has mass less than 1.0g will have density less than 1.0g.
For example aqueous solution of sulfuric acid has density 0.98g/mL.
That means 1mL of sulfuric acid has mass 0.98g.
Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water, for example, sulfuric acid which has a density 0.98g/mL.
What is density of a substance?The density of a substance is the ratio of the mass to the volume of that substance.
Density measures compactness.
More compact substances are more dense.
The density of water is about 1.0 g/mL at room temperature.
This means that 1.0mL of water weighs 1.0g
1.0 mL of an aqueous solution whose mass is less than 1.0g will have density less than that of water.
Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water.
An example of an aqueous solution whose density is less than that of water is sulfuric acid which has a density 0.98g/mL.
Sulfuric acid is prepared by dissolving sulphur (vi) oxide, a gas, in water.
This means 1mL of sulfuric acid has mass 0.98g.
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2 kg of hydrogen (H2) is mixed with 2 kg of oxygen (O2). If the final mixture has a volume of 3 m3: Determine (a) molar mass (b) specific volume and (c) the molar specific volume of the final mixture.[Solution] [Discuss]
Answer:
Explanation:
The molar mass of a given substance corresponds and pertains to the unit mole of the mass substance which is stated in g/mol
no of moles of H = mass of H/molar mass of H
= 2 kg/ 2 g/mol
= 2000 g/ 2 g/mol
= 1000 moles
moles of O2 = mass (O2)/ molar mass (O2)
= 2 kg/ 32 g/mol
= 2000 g / 32 g/mol
= 62.5 moles
Total moles present = (1000 + 62.5) moles
= 1062.5 moles
= 1.063 kmol
Total mass = 2kg + 2kg
= 4 kg
no of moles = mass/molar mass
molar mass = mass/ no of moles
molar mass = 4 kg/ 1.063 kmol
molar mass = 3.763 kg/kmol
The specific volume of the final mixture can be determined by the relation:
[tex]v_{mixture}=\dfrac{ V}{m}[/tex]
where;
V = 3 m³
m = 4 kg
[tex]v_{mixture}=\dfrac{ 3 \ m^3}{4 \ kg}[/tex]
= 0.75 m³/ kg
For the final volume, The molar specific volume is:
[tex]v_M = M_{mixture} *v_{mixture}[/tex]
where;
[tex]M_{mixture} = 3.763[/tex]
[tex]v_{mixture} = 0.75 \ m^3/ kg[/tex]
∴
[tex]v_M = 3.763 \ kg/mol \times 0.75 \ m^3/kg[/tex]
[tex]\mathbf{v_M = 2.82 \ m^3/kmol}[/tex]
wich statement describes one way that RNA differs from DNA?
Answer:
They contain different five-carbon sugars and a different nitrogenous base.
Of the following transitions in the Bohr hydrogen atom, the ________ transition results in the absorption of the highest-energy photon.\
Answer:
The options are
A) n = 1 → n = 6
B) n = 6 → n = 1
C) n = 6 → n = 3
D) n = 3 → n = 6
E) n = 1 → n = 4
The answer is A) n = 1 → n = 6
The transition results in the absorption of the highest-energy photon. This is because absorption typically involves the movement from a lower energy state to a higher level.
The answer here is B as a result of it being the option which moves from a lower state to a higher state with a bigger margin than the rest.
Highlight the larger value.
[H+] = 4.3 x 10^-4
[H+] = 4.3 x 10^-6
Answer:
4.3 is your answer because it's matches
Sort the following molecules or ions into their proper three-dimensional molecular shapes. Drag the appropriate molecules or ions to their respective bins.
1. NBr3
2. SO2
3. SBr42+
4. SO42+
5. CF3Cl
A. Tetrahedral
B. Trigonal pyramidal
C. Bent
D. Linear
E. Trigonal planar
Answer:
NBr3 - Trigonal pyramidal
SO2- Bent
SBr42+- Tetrahedral
SO42- Tetrahedral
CF3Cl - Tetrahedral
Explanation:
The shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule. This is well captured in the valence shell electron poair repulsion theory.
The number of electron pairs on the outermost shell of the central atom in a molecule are called regions of electron density. According to this theory, these regions of electron density must be positioned as far apart from each other as possible to minimize repulsions between electron pairs.
This theory is the basis of the shapes of molecules shown in the answer. If a molecule has four regions of electron density, it could be trigonal pyramidal or tetrahedral in shape such as NBr3 and CF3Cl.
Note that, when deciding on the three dimensional geometry of a molecule, only the covalent bonds present are considered.
The average potential energy of water molecules is greatest in
The average potential energy of water molecules is greatest in in steam at 100 °C. Potential energy is indeed a characteristic of a system.
What is potential energy?Potential energy is stored energy that is affected by the relative location of various components in a system. When a spring is squeezed or extended, its potential energy increases.
Potential energy is indeed a characteristic of a system, not an individual substance or particle; for example, the system made of Earth and the elevated ball has greater potential energy as even the two are separated. Potential energy exists in systems having pieces that exert forces on one another of varying magnitudes based on their configuration, or relative location. The average potential energy of water molecules is greatest in steam at 100 °C.
Therefore, the average potential energy of water molecules is greatest in steam at 100 °C.
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what is an example of reactivity?
4 AlF3 + 3 O2 ----------> 2Al2O3 + 6 F2
How many moles of AlF3 is needed to produce 8.25 moles of F2 from the given balanced equation shown above? (SHOW WORK)
Explanation:
6 F2------->4 AlF3
F2-----------> 4/6 AlF3
8.25 F2 ---------> 4×8.25/6 AlF3
so 5.5 moles
how to solve the chemical formula for Calcium Chlorate
Answer:
Ca(ClO3)2
Explanation:
The chemical formula of calcium chlorate is Ca(ClO3)2, which means in this molecule, Ca2+ ion is bonded to two ClO3- ions. So the formula can be expended to O3Cl-Ca-ClO3, or CaCl2O6 (basically times the numbers of the elements inside the bracket by the number outside the bracket.
The first step in ozonolysis of an alkene is the formation of an unstable cyclic molozonide. Reaction of Alkene with Ozone Write a mechanism for the reaction using curved arrows to show electron reorganization.
Answer: hello your question is incomplete , the complete question is attached below
answer:
Attached below
Explanation:
The mechanism for the reaction that shows electron reorganization is attached below ( i.e. Reaction of Alkene with Ozone )
A hard-water solution contains 4.8 g of calcium chloride. How much sodium phosphate in grams should be added to the solution to completely precipitate all of the calcium
Answer:
4.7 g
Explanation:
The reaction that takes place is:
3CaCl₂(aq) + 2Na₃PO₄(aq) → Ca₃(PO₄)₂(s) + 6NaCl(aq)First we convert 4.8 g of CaCl₂ into moles, using its molar mass:
4.8 g ÷ 110.98 g/mol = 0.0432 mol CaCl₂Then we convert CaCl₂ moles into Na₃PO₄ moles, using the stochiometric coefficients of the balanced reaction:
0.0432 mol CaCl₂ * [tex]\frac{2molNa_3PO_4}{3molCaCl_2}[/tex] = 0.0288 mol Na₃PO₄Finally we convert 0.0288 moles of Na₃PO₄ into grams, using its molar mass:
0.0288 mol Na₃PO₄ * 164 g/mol = 4.7 gWashes and extractions are both techniques that use a separatory funnel to separate liquid layers. However, washes and extractions have differences. Determine whether each statement applies to washes or extractions.
Leaves impurities in their starting layer Choose...
Moves impurities from one layer to another Choose...
Moves desired compound from one layer to another Choose...
Often involves a reaction in one of the layers Choose...
Leaves desired compound in its starting layer Choose...
Answer:
Leaves impurities in their starting layer - Extraction Moves impurities from one layer to another - Wash Moves desired compound from one layer to another - Extraction Often involves a reaction in one of the layers - Extraction Leaves desired compound in its starting layer - WashExplanation:
Both extraction and wash are technical materials separation processes. Both seek to carry out a separation of liquid-liquid, through the relationship between solvent and solute present in this solution. Both use a separation funnel and are very similar processes where the main difference is the purpose that each one seeks to exercise. The extraction causes the dissolution of the material that the researcher wants to leave behind. this process leaves impurities in the initial solution layer and moves the researcher's desired compound to the second layer of solution. A chemical reaction can take place during this process.
A wash, on the other hand, dissolves all impurities from the solution and extracts the compound desired by the researcher. Therefore, we can conclude that during this process the impurities are moved from one layer to another in the solution until it is discarded from the funnel, leaving the desired compound in the initial layer.
Give the change in conditions required to go from a gas to a solid. Give the change in conditions required to go from a gas to a solid. Decrease temperature or reduce pressure. Increase temperature or reduce pressure. Increase temperature or increase pressure. Decrease temperature or increase pressure. None of the above.
Answer:
Decrease temperature or reduce pressure
What happens to the equilibrium between NO2(g) and N2O4(g) in inert argon when the volume is increased and additional argon is added to maintain a constant total pressure
Answer:
Equilibrium will be shifted towards NO2 as it has the most of the moles in the reaction.
Explanation:
Hello there!
In this case, according to the equilibrium reaction between NO2 and N2O4, we are able to write:
[tex]2NO_2(g)\rightleftharpoons N_2O_4(g)[/tex]
We can recall the LeCha-telier's principle to realize that the increase of volume promotes the formation of the most of the moles, this is for NO2 because it has a coefficient of 2 and N2O4 a coefficient of 1; in such a way, we infer that the addition of argon, to increase the pressure, will shift the equilibrium towards NO2.
Regards!
Please help me describe
Answer:
Electronegativity (EN): A measure of an atom's ability to attract electrons (or electron density) toward itself.
Atomic Radius(R) is defined as one-half the distance between the nuclei of identical atoms that are bonded together.
Ionization Energy is the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule.
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Phenols do not exhibit the same pka values as other alcohols; they are generally more acidic. Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane
Answer:
Phenols do not exhibit the same pka values as other alcohols;
They are generally more acidic.
Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane.
Explanation:
According to Bromsted=Lowry acid-base theory,
an acid is a substance that can release [tex]H^{+}[/tex] ions when dissolved in water.
So, acid is a proton donor.
If the conjugate base of an acid is more stable then, that acid is a strong acid.
In the case of phenol,
the phenoxide ion formed is stabilized by resonance.
[tex]C_6H_5OH -> C_6H_5O^- +H^+[/tex]
The resonance in phenoxide ion is shown below:
Whereas in the case of cyclohexanol resonance is not possible.
So, cyclohexanol is a weak acid compared to phenol.
Which equation represents a neutralization reaction? 1. Ca(OH) 2 Ca^ 2+ +2OH^ - 2. CaCl 2 Ca^ 2+ +2Cl^ - 3 H^ + +OH^ - HOH 4. H^ + +F^ - HF
You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 12, and each shift lasts 75. Your laundry requires 12 quarters/load.
A. How many shifts must you work if you wish to wash 10 loads of laundry?
B. How many loads of laundry can you wash if you work 3 shifts?
C. How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?
Answer:
A. 2 shifts
B. 15 loads of laundry
C. 3.75 loads of laundry
Note: The question is missing some details. A similar complete question is given below:
You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 12 dollars/hour, and each shifts lasts 75 minutes. Your laundry requires 12 quarters/load. How many loads of laundry can you wash if you work 3 shifts? How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?
Explanation:
The following information is provided :
Amount earned per hour = 12 dollars/hour
Duration for one shift = 75 minutes = 1.25 hours
Cost per load = 12 quarters/load
A. Cost of 10 loads of laundry = 12 × 10 = 120 quarters
120 quarters = 120/4 dollars = 30 dollars
Time taken to earn 30 dollars = 30/12 × 1 hour = 2.5 hours
Number of shifts required in 2.5 hours = 2.5/1.25 = 2 shifts
Therefore, 2 shifts are required to wash 10 loads of laundry
B. Duration of 3 shifts = 1.25 hours × 3 shifts = 3.75 hours
Amount earned in 3 shifts = 3.75 × 12 = 45 dollars
12 quarters/load = 12 × 0.25 dollars = 3 dollars/load
Number of loads that can be washed = 45/3 = 15 loads of laundry
Therefore, 15 loads of laundry can be washed in 3 shifts
C. 16 quarters/load = 16 × 0.25 = 4 dollars/ load
Amount earned per shift = 1.25 × 12 =15 dollars
Loads of laundry per shift = 15/4 = 3.75 loads
Therefore, 3.75 loads will be paid per shift
