Oil-based food coloring used to make the letters, won't dissolve in water. According to some sources, oil-based food coloring is either insoluble or immiscible in water. Because it is present in more solutions, water serves as the universal solvent.
Universal solvent:-A substance that displaces most compounds is known as a universal solvent. Because it dissolves more chemicals than any other solvent, water is known as the universal solvent.
What chemicals lack solvability?Sand, plastic, wood, metal, glass, and cloth are examples of insoluble materials. At standard conditions of pressure and temperature, these compounds never dissolve in water or any other solvent. Other examples of insoluble materials are sugars and inorganic salts.
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Questions & Conclusions:
4. How much KNO, precipitated out of solution when you cooled the solution from 100°C to -22°C?
(Keep in mind that you only started with 10 grams of each solute.)
The amount of KNO₃ precipitated out of solution when you cooled the solution from 100°C to -22°C is obtained from the solubility curve
What is a solubility curve?A solubility curve is a curve of the solubility of a solute against temperature.
The solubility curve shows that the solubility of different solute at different temperatures.
The solubility curve of KNO₃ is as shown. Solubility at 100 °C and -22 °C is not shown in the curve.
However, the amount of KNO₃ precipitated out of solution when cooled the solution from 100 °C to -22 °C can be determined by subtracting the amount of solute dissolve at -22 °C from that dissolved at 100 °C.
In conclusion, the solubility curve is used to determined the amount of solute dissolved in a given volume of solvent at different temperatures.
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What is the change in internal energy, DE, for a system that does 70 joules of work as it absorbs 45 joules of heat
-25 J is the change in internal energy, for a system that does 70 joules of work as it absorbs 45 joules of heat.
What is First Law of Thermodynamics ?According to first law of thermodynamics energy cannot be created or destroyed but it can be changed from one form to another. First law of thermodynamics is also known as the law of conservation of energy.
Equation of first law of thermodynamics
ΔU = Q - W
where,
ΔU = Change in internal energy
Q = Heat added to the system
W = Work done by the system
Now put the values in above equation
ΔU = Q - W
= 45 - 70
= -25 J
Thus from the above conclusion we can say that -25 J is the change in internal energy, for a system that does 70 joules of work as it absorbs 45 joules of heat.
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in reacting 12 moles of pb2+ ions with 18 moles of cl- ions, the theoretical molar yeild of lead (II) chloride is
The theoretical molar yield of lead (II) chloride will be 9 moles.
Stoichiometric calculationFirst, we need to look at the equation of the reaction:
[tex]Pb^{2+} + 2Cl^- --- > PbCl_2[/tex]
From the equation, the 1 mole of Pb2+ ion requires 2 moles of Cl- ion in order to produce 1 mole of lead (II) chloride.
Thus, with 18 moles Cl- ions, 9 moles of Pb2+ would be needed, instead of 12 moles. Pb2+ is simply in excess while Cl- can be said to be limiting.
Therefore, Cl- will determine how much of lead (II) chloride that will be produced. The ratio is 2 moles of Cl- to 1 mole of lead (II) chloride.
With 18 moles Cl-, 9 moles of lead (II) chloride will, thus, be produced.
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A 13.5 g sample of an aqueous solution of nitric acid contains an unknown amount of the acid. If 23.5 mL of 0.434 M barium hydroxide are required to neutralize the nitric acid, what is the percent by mass of nitric acid in the mixture
The percent by mass of nitric acid in the mixture is 3.36 %
2 HNO3 + Ba(OH)2 --->Ba(NO3)2 + 2H2O
so 1 mole Ba(OH)2 neutralizes 2 mol HNO3
moles of Ba(OH)2 present = molarity of base* volume of base
= 0.229 M * 15.6 ml
= 3.5724 milli mols
mols of HNO3 neutralized = 2* mols of Ca(OH)2 used
= 2* 3.5724 milli mols = 7.1448 x10^-3 mols
molar mass of HNO3 = 63.01 g/mol
mass of HNO3 present = molar mass * mols of HNO3
= 63.01 g/mol * 7.1448 x10^-3 mols
=0.4502 g
mass of sample = 13.4 g
mass % = mass of HNO3/mass of sample * 100
= 0.4502/13.4 *100
= 3.36 %
Nitric acid is a colorless, fuming, and distinctly corrosive liquid that could be a not unusual laboratory reagent and an important commercial chemical for the manufacture of fertilizers and explosives.
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4. You have a 1 M solution of KCl. You need to generate 100 mL of 0.25 M KCl. Explain how you would make this
1M KCl will require 25 mL to generate 100 mL of 0.25M KCl.
Molarity of a solution is defined as number of moles of solute present in 1000 mL of the solution.
[tex]M=\frac{n}{V}\times1000[/tex]
So molarity is inversely proportional to the volume of the solution.
As solution is diluted. Molarity of the solution decreases.
1M of KCl means 1 mole of KCl in 1000 mL of the solution.
1M KCl is four times as concentrated as 0.25M KCl.
Therefore, to make 100 mL of 0.25M will require [tex]\frac{100}{4}= 25 mL[/tex] of 1M KCl diluted to 100 mL of distilled water.
Easy alternative: Dilution formula
[tex]M_1\times V_1 = M_2\times V_2[/tex]
Where [tex]M_1 \,and\, V_1[/tex] are volume and concentration of first solution
and [tex]M_2\,and\, V_2[/tex] are of second solution.
[tex]1\times V= 0.25\times100\\\\V= 25\,mL[/tex]
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Sodium bromate is used in a mixture which dissolves gold from its ores. The mass of 4.68 mol of sodium bromate is ____ g. Enter a number in the blank space provided. _____ g
706.1652 g is the molar mass of 4.68 mol of sodium bromate.
Given:
Sodium bromate is used in a mixture which dissolves gold from its ores.
Moles of sodium bromate= 4.68 mol
Molar mass of sodium bromate = 150.89 g/mol number of moles × mol
= 150.89 × 4.68
= 706.1652 g
Therefore, 706.1652 g is the molar mass of 4.68 mol of sodium bromate.
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A severe systemic reaction to an allergen causing serious symptoms that develop very quickly is known as.
Answer: Anaphylaxis
Explanation:
I have a nut allergy, and this has happened to me once. The doctors also told me a lot about anaphylaxis, and I like to learn about myself.
I hope this helps!! :)
The diffusion of substances within a solution tends to move those substances ________ their ________ gradient.
What is diffusion?
The diffusion of substances within a solution tends to move those substances down their concentration gradient.
Aim of diffusion:
The movement of molecules along a concentration gradient is known as diffusion. It is a significant process that all living things go through. Diffusion facilitates the flow of materials into and out of cells. Until the concentration is the same everywhere, the molecules travel from a location of higher concentration to a region of lower concentration.
Diffusion occurs in gases and liquids because random molecular movement is possible.
Types of diffusion:
Simple diffusion and facilitated diffusion are the two primary categories of diffusion.
Simple diffusion: An action where the substance passes across a semipermeable barrier or solution without the aid of transport proteins. For instance, bacteria use simple diffusion to transport minute nutrients, water, and oxygen into the cytoplasm.Facilitated diffusion: It is the passive transfer of molecules from the area of higher concentration to the area of lower concentration across the cell membrane using a carrier molecule.The main aim of diffusion is to arrive at an equilibrium state. When the amount of the particles is uniformly distributed or constant throughout a solution, it is said to be in equilibrium.
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A reaction which creates larger molecules from substrates and results in water as a byproduct would be catalyzed by a ________ enzyme.
A reaction that creates larger molecules from substrates and results in water as a byproduct would be catalyzed by a synthase enzyme.
What is synthase?Synthase is an enzyme that catalyzes the synthesis of new compounds in the body. As a result, it is a very widespread enzyme that can be found in both higher and lower-order species. Synthases do not use energy from nucleoside triphosphates.
A synthase is a ligase that joins two chemicals or compounds together with the need for energy, whereas a synthase is a lyase that catalyzes the breakage of numerous chemical bonds through methods other than hydrolysis and oxidation.
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Write the chemical symbol for an element in Period 2 and Group 2A.
Answer:
Be
Explanation:
From Periodic table , group 2 a is the VERTICAL group including
Be Mg Ca Sr Ba Ra
period 2 is the HORIZONTAL line including Li Be B C N O F
Be beryllium is the element in both of these categories
The chemical symbol for an element in Period 2 and Group 2A is beryllium. Which is present in both of these categories.
What is the periodic table ?The term periodic table is defined as the arrangements of chemical elements in rows and column according to their atomic number.
In the rows, the elements are present according to their atomic number. The columns produce groups of elements that have similar chemical characteristics.
From the Periodic table , Group 2A is the vertical group containing elements like the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).While Period 2 is the horizontal line containing elements like Li, Be, B, C, N, O, F.
Thus, The chemical symbol for an element in Period 2 and Group 2A is beryllium. Which is present in both of these categories.
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To end up with 100 mL of a 1.0 mg/mL solution of analyte, an analyst should measure _____ of a 15.5 mg/mL analyte solution into a 100-mL volumetric flask and dissolve to the mark.
V₂ = 6.45 mL (volume of analyte)
CalculationHere we use dilution formula, which is:
C₁V₁ = C₂V₂
where,
C₁ = initial concentration
V₁ = initial volume
C₂ = final concentration
V₂ = final volume
Given data,
C₁ = 1.0 mg/mL
C₂ = 15.5 mg/mL
V₁ = 100 mL
V₂ = ? (to be found)
Putting the values in the formula, we get:
1 × 100 = 15.5 × V₂
V₂ = 100/15.5
V₂ = 6.45 mL
Why would you use a formula for dilution?A solution is diluted when more solvent is added without increasing solute. The final mixture is thoroughly mixed to make sure that every component is the same.
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4. Hot exhaust gases are often used in a chemical plant to heat chemical reactions before the
gases are discharged to the atmosphere. If 10.0 L of gas at 300°C and 3.00 atm expand to
125 L at 1.00 atm during the heat exchange process, what is the temperature of the gas
that is released to the atmosphere?
Answer:
1,250 °C
Explanation:
To find the new temperature, you need to use a variation of the Combined Gas Law. The equation looks like this:
P₁V₁ / T₁ = P₂V₂ / T₂
In this formula, "P₁", "V₁" and "T₁" represent the initial pressure, volume, and temperature. "P₂", "V₂", and "T₂" represent the final pressure, volume, and temperature. You can find the new temperature by plugging the given values into the equation and simplifying.
P₁ = 3.00 atm P₂ = 1.00 atm
V₁ = 10.0 L V₂ = 125 L
T₁ = 300 °C T₂ = ? °C
P₁V₁ / T₁ = P₂V₂ / T₂ <----- Combined Law equation
(3.00 atm)(10.0 L) / (300 °C) = (1.00 atm)(125 L) / T₂ <----- Insert values
0.1 = (1.00 atm)(125 L) / T₂ <----- Simplify left side
0.1 = 125 / T₂ <----- Multiply 1.00 and 125
0.1 x T₂ = 125 <----- Multiply both sides by T₂
T₂ = 1,250 <----- Divide both sides by 0.1
1. Write out the following reaction in word form, then describe the type of reaction.
C₂H6 (3) + O2(g) →CO2(g) + H₂O (9)
Answer:
ethylene(ethane) + oxygen → carbon dioxide + water
the type of reaction is COMBUSTION.
What is the Bronsted-Lowry definition of an acid?
• a compound that donates protons
a compound that accepts protons
• a substance that increases hydroxide ion concentration
a substance that increases hydronium ion concentration
Answer:
A. a compound that donates protons
Explanation: According to the Brønsted-Lowry definition, an acid is a substance that can donate a proton (H+ ion) to another molecule. A base is a substance that can accept that donated H+. After the Brønsted-Lowry acid donates its proton, it becomes the conjugate base of the acid.
Answer:
A: a compound that donates protons.
Explanation:
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To produce electricity a generator needs what kind of imput
Answer: Mechanical Energy
Explanation:
To produce electricity, a generator needs an input of mechanical energy. Mechanical energy is a combination of potential energy and kinetic energy. Generators use this to create electricity to power light bulbs, technological devices, and more!
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Assuming an efficiency of 30.40%, calculate the actual yield of magnesium nitrate formed from 130.8 g of magnesium and excess copper(II) nitrate.
The actual yield of magnesium nitrate formed from 130.8 g of magnesium and excess copper(II) nitrate is 245.2 g.
What is Balanced Chemical Equation ?The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.
The balanced chemical equation is as follows:
Mg + Cu(NO₃)₂ → Mg(NO₃)₂ + Cu
How to find the actual yield ?To calculate the actual yield use the expression
Actual yield = Efficiency × theoretical yield
Number of moles = [tex]\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
= [tex]\frac{130.8}{24}[/tex]
= 5.45
Efficiency moles of Mg(NO₃)₂ = 0.304 × 5.45
= 1.6568 mol
Now put the value in above expression
Actual yield = Efficiency × theoretical yield
= 1.6568 × 148
= 245.2 g
Thus from the above conclusion we can say that The actual yield of magnesium nitrate formed from 130.8 g of magnesium and excess copper(II) nitrate is 245.2 g.
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To which group does copper belong?
a. Metalloid
b. Alkaline earth metal
c. Alkali metal
d. Transition metal
Answer:
d. Transition metal
Explanation:
A transition metal is an element which has an atom or forms an ion with a partially-filled d-subshell.
As we can see from the electronic configuration of Copper 2+ ion, Cu²⁺:
[tex]_{27}Cu^{2+} = 1s^2\space\ 2s^2 \space\ 2p^6 \space\ 3s^2 \space\ 3p^6 \space\ 3d^9[/tex] ,
copper forms an ion with an incomplete d-subshell that contains 9 electrons; therefore copper is a transition metal.
• Option a. is wrong because copper is not a metalloid. Metalloids have characteristics of both metals and non-metals; copper only has metallic properties.
• Option b. is wrong because 'alkaline earth metals' are the elements in Group 2 of the periodic table; copper is in Group 11.
• Option c. is wrong because 'alkali metals' are in Group 1 of the periodic table.
The first eight ionization energies of a third row element are 999.6, 2252, 3357, 4556, 7004, 8496, 27107, and 31719 kJ/mol. Identify the element.
The first eight ionization energies of a third row element are 999.6, 2252, 3357, 4556, 7004, 8496, 27107, and 31719 kJ/mol. The element is S.
Hence, Option C is correct answer.
What is Ionization Energy ?Ionization energy is the energy that an electron in a isolated gaseous atom or ion in the ground electronic state must absorb to discharge an electron resulting in a cation.
Which element belongs to third row or period ?The third row element are Na, Mg, Al, Si, B, S, Cl, Ar
From the given options these elements belongs to third row Na, Mg, Al, Si, S, Cl, Ar.
Now check the first eight ionization energy of each element.
Na: 496, 4562, 6910, 9543, 13354, 16613, 20117, 25496 kJ/mol
Mg: 738, 1451, 7733, 10543, 13630, 18020, 21711, 25661 kJ/mol
Al: 578, 1817, 2745, 11577, 14842, 18379, 23326, 27465 kJ/mol
Si: 787, 1577, 3232, 4356, 16091, 19805, 23780, 29287 kJ/mol
S: 999.6, 2252, 3357, 4556, 7004, 8496, 27107, 31719 kJ/mol
Cl: 1251, 2298, 3822, 5159, 6542, 9362, 11018, 33604 kJ/mol
Ar: 1521, 2666, 3931, 5771, 7238, 8781, 11995, 13842 kJ/mol
Thus from the above conclusion we can say that The first eight ionization energies of a third row element are 999.6, 2252, 3357, 4556, 7004, 8496, 27107, and 31719 kJ/mol. The element is S.
Hence, Option C is correct answer.
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Disclaimer: The question was given incomplete on the portal. Here is the complete question.
Question: The first eight ionization energies of a third row element are 999.6, 2252, 3357, 4556, 7004, 8496, 27107, and 31719 kJ/mol. Identify the element.
Choose One:
A. Mg
B. Cl
C. S
D. P
E. Al
F. Ar
G. Na
H. Si
What happens to the electron cloud at very high atomic numbers, when the innermost electrons would, using a non-relativistic model, be calculated to exceed the speed of light?
Answer:
tough question
Explanation:
In a non-relativistic model, the speed of an electron in an atom can be calculated using classical mechanics. The speed of an electron in the nth energy level is given by the formula:
[tex]\rm \[v_n = \sqrt{\frac{{2 \cdot E_n}}{{m_e}}}\][/tex]
where [tex]\rm \(v_n\)[/tex] is the speed of the electron, [tex]\rm \(E_n\)[/tex] is the energy of the electron in the nth energy level, and [tex]\rm \(m_e\)[/tex] is the mass of the electron.
For very high atomic numbers, the energy of the innermost electrons can become extremely large, leading to high speeds according to the non-relativistic formula.
However, as the speed of an object with mass approaches the speed of light [tex]\rm \(c\)[/tex] which is approximate [tex]\rm \(3 \times 10^8\) m/s[/tex], relativistic effects become significant, and the non-relativistic formula breaks down.
The relativistic speed of an electron is given by:
[tex]\rm \[v_{rel} = \frac{{v_n}}{{\sqrt{1 - \frac{{v_n^2}}{{c^2}}}}}\][/tex]
As the speed of the electron approaches [tex]\rm \(c\)[/tex], the denominator approaches zero, and the relativistic speed [tex]\rm \(v_{rel}\)[/tex] approaches infinity, preventing the electron from ever reaching or exceeding the speed of light.
In summary, at very high atomic numbers, the innermost electrons do not actually exceed the speed of light due to the relativistic effects that prevent such occurrences, and the electron cloud remains consistent with the principles of special relativity.
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A sample of neon gas has a volume of 752 mL at 298 Kelvin (K). What will be the volume at 373 K if
pressure is constant?
Answer:
V2 = 0.941 L
Explanation:
This follows the Charles' law, a gas law.
Using this eq [tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]
From the given, the missing variable is V2
[tex]\frac{752 ml}{298 K} =\frac{V2}{373 K}[/tex], change ml to SI unit of Volume (L)
752 ml = 0.752 L
[tex]\frac{752 L}{298 K} =\frac{V2}{373 K}[/tex], then cross multiply
[tex]280.496 L (K) =298K (V2)[/tex]
[tex]\frac{280.496 L (K) }{298K} = (V2)[/tex]
[tex]V2 = 0.941 L[/tex]
In its organic form, ____ is usually (not always) related with the metabolic processes of living organisms.
Answer:
In its organic form, metabolism is usually (not always) related with the metabolic processes of living organisms.
Explanation:
In this context, metabolism refers to how quickly a person's body consumes any fuel it consumes. Because the energy from meals is used up more rapidly when someone has a high metabolism, they require food more frequently. These folks typically feel and are warmer. A person with a high metabolism may not acquire as much weight as they would expect even if they eat more since their body uses up the food before it can be converted to fat or muscle. Consider an automobile where the accelerator has been floored. More frequent gas additions would be required, and the engine's temperature would rise. Slower metabolisms function like an idle automobile. They typically don't need to eat as frequently since their bodies use fuel more slowly. The quantity people typically consume may, however, exceed what they truly require to maintain their current state of health. They constantly use additional fuel, which tends to be stored as fat. Thus, it is not always true that everyone who is slim has a fast metabolism and everyone who is overweight has a sluggish one. It ultimately comes down to how many calories you consume against how many your body actually requires. Simply said, a person's metabolism may make or break this score relative to the norm. Therefore, those with slower metabolisms tend to put on weight quickly since they require less food than predicted to maintain their bodies whereas those with faster metabolisms prefer to be slim because of this.
atmosheric concentraion of green house gases such as carbon dioxide are higher than at any time in earth history. T/F
The atmospheric concentration of carbon dioxide:
The statement "Atmospheric concentration of greenhouse gases such as carbon dioxide are higher than at any time in earth history", is True.
Greenhouse Gas:
It is a gas that causes the greenhouse effect by both absorbing and emitting radiant energy in the thermal infrared region.Water vapor, carbon dioxide, methane, nitrous oxide, and ozone (O3) are the main greenhouse gases in the Earth's atmosphere.Earth's surface would typically be roughly -18 °C if greenhouse gases weren't there.In addition to causing respiratory problems from smog and air pollution, greenhouse gas also contribute to climate change by trapping heat. Other consequences of climate change includes extreme weather, interruptions in the food supply, and a rise in wildfires.Since the start of the industrial period, carbon dioxide concentrations have significantly grown, rising from an annual average of 280 ppm in the late 1700s to 410 ppm in 2019 to an increase of 1.8 ppm over 2021.
The net emissions of greenhouse gases resulting from human activity rose by 43%. The carbon dioxide emissions, which make up nearly three-fourths of all emissions, rose by 51%. Similar to the United States, the bulk of emissions in the world come from energy production and use, including power generation, transportation, and other energy-related activities.
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When selecting a photometric technique that is more sensitive to a low concentration of analyte, a laboratory director compares absorbance measuring devices against those that measure fluorescence intensity. Which technique is considered more sensitive in its measurements and why
When selecting a photometric technique that is more sensitive to a low concentration of analyte, a laboratory director compares absorbance measuring devices against those that measure fluorescence intensity. Fluorescence spectroscopy is considered more sensitive in its measurements.
Spectro-fluorometer works on the above mentioned principle...
It uses a beam of light to excite the electrons from the given material which cause the emission of light from that matter.The emitted light is then brought towards a filter and onto a detector for measurement and identification of the changes in molecules of a sample material.Fluorometry is sensitive technique because light of particular wavelength is required as electrons are getting excited from ground state to emit the light and shows particular results which helps to know the sample material.Learn more about spectroscopy here..
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Which real-world scenarios below represent physical changes? Check all that apply.
Answer:
wheres the options?
Explanation:
Which two solutions, when mixed together, will undergo a double replacement reaction and form a white, solid substance?
(1) NaCl(aq) and LINO3(aq)
(2) KCl(aq) and AgNO3 (29)
(3) KCl(aq) and LiCl(aq)
(4) NaNO3(aq) and AgNO3(aq)
[tex]AgNO_3 + KCl[/tex] → [tex]AgCl + KNO_3[/tex] undergo a double replacement reaction and form a white, solid substance. Hence, option B is correct.
What is a double replacement reaction?A double replacement reaction is a type of chemical reaction that occurs when two reactants exchange cations or anions to yield two new products.
Double-replacement reactions generally occur between substances in aqueous solution. In order for a reaction to occur, one of the products is usually a solid precipitate, a gas, or a molecular compound such as water.
[tex]AgNO_3 + KCl[/tex] → [tex]AgCl + KNO_3[/tex] undergo a double replacement reaction and form a white, solid substance.
Hence, option B is correct.
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By mass spectral analysis, a sample of strontium is known to contain 2.64x1010 atoms of Sr-90 as the only radioactive element. The absolute disintegration rate of this sample is measured as 1238 disintegrations per minute. Calculate the half-life (in years) of Sr-90. Answer: 28.49 Question 14 Not answered Marked out of 1.00 Question text How long will it take (in years) for the disintegration rate of this sample to drop to 878 disintegrations per minute
It will take 14.13 years for the disintegration rate of this sample to drop to 878 disintegrations per minute.
Given that,
Half life of Sr-90 = 28.49 years
This decay process is first order decay kinetics
So according to [tex]1^{st}[/tex] order reaction
Half life = 0.693/k
k= 0.693/28.49
k= 0.0243 [tex]years^{-1}[/tex]
According to the integrated rate law for [tex]1^{st}[/tex] order reaction
ln[Rn] = ln[Rn][tex]{o}[/tex] - kt …..(1)
where, Rn = 878 disintegrations/minute
Rn[tex]_{o}[/tex] = 1238 disintegrations/minute
Putting the values in equation (1)
ln[878] = ln[1238] - 0.0243 × t
6.7776 = 7.1212 - 0.0243 × t
0.0243t = 0.3436
t= 14.13 years
Hence, it will take 14.13 years for the disintegration rate of this sample to drop to 878 disintegrations per minute.
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J.J. Thomson discovered the electron by noticing that: A. molecules with the same atoms exhibited the same chemical properties. OB. a beam of particles could be influenced by an electric or magnetic force. C. chemical compounds contained various combinations of at least two atoms. D. some particles in a beam were deflected when passed through a sheet of gold foil.
J.J. Thomson discovered the electron by noticing that a beam of particles could be influenced by an electric or magnetic force and is denoted as option B.
What is an Electron?This is referred to a subatomic particle which has a negative charge present and is involved in chemical reactions.
J.J. Thomson noticed that cathode rays were negatively charged due to deflection by magnetic and electric forces which signifies the presence of a negative particle.
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75.0 g sample of a metal at 65°C is added to 100.0 g of water at 20.0°C. The temperature of the water rises to 22.3 °C. Calculate the specific heat of the metal, assuming that all the heat lost by the metal is gained by the water.
The specific heat of the metal is 0.30J/g°C.
What is specific heat capacity?The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).
Step 1: Data given
Mass of metal = 75.0 g
Temperature of the metal = 65°C
Mass of water = 100.0 g
Temperature of the water = 20.0°C
Final temperature of the water = 22.3 °C
The specific heat of water is 4.184 J/g°C
Step 2: Calculate the specific heat of metal
Qlost = -Qgained
Q= m xCxΔT
Qmetal = -Qwater
m(metal) x c(metal) x ΔT(metal) = - m(water) x c(water) x ΔT(water
⇒m(metal) = the mass of metal = 75.0 g
⇒c(metal) = the specific heat of the metal = ?
⇒ΔT = The change of temperature = 22.3 - 65°C = -42.7 °C
⇒m(water) = the mass of water = 100.0 g grams
⇒c(water) = the specific heat of water = 4.186 J/g°C
⇒ΔT(water) = T2 - T1 = 22.3 - 20.0 = 2.3 °C
75.0 g x c(metal) x -42.7 °C= -100.0 g x 4.186 x 2.3
75.0 g x c(metal) x -42.7 °C = −962.78
c(metal) = 0.3006338798J/g°C =0.30J/g°C
The specific heat of the metal is 0.30J/g°C.
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7.How would the number of moles (n) of O2 change if your atmospheric pressure was doubled and all other variables stayed the same
The number of moles (n) of O2 will be double if atmospheric pressure was doubled and all other variables stayed the same.
About Ideal gas LawThe general gas equation, often known as the ideal gas law, is the equation of state for a fictitious ideal gas. It has a number of limitations, but it provides a decent approximation of the behavior of numerous gases under various circumstances.
Explanation:Applying the law of ideal gas: PV = nRT.
where,
P= pressure of the gas in the atm.
V= volume of the gas in L.
n = no. of moles of the gas in mol.
R = Universal gas constant,
T = temperature of the gas in K.
If V and T are constant and have different values of P and n:
(P₁n₂) = (P₂n₁).
P₂ = 2P₁,
∴ n₂ = (P₂n₁)/(P₁) = (2P₁n₁)/(P₁) = 2n₁.
therefore if we double the pressure then no. of the moles of O2 will be doubled.
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Crystallizing salt from seawater, ripening fruit, and production of elements in the stars are energy/matter changes. These changes could be classified respectively as
The changes in matter/energy can be classified as follows:
Physical changes - Crystallizing salt from seawaterChemical changes - ripening fruitNuclear changes - production of elements in the starsWhat are physical, chemical and nuclear changes?Matter and energy undergo physical, chemical and nuclear changes.
Physical changes are changes in which no new product is formed.
Chemical changes are changes in which no new product is formed.
Nuclear changes are changes in which no new product is formed.
Examples of each of the given changes is as follows:
Physical changes - Crystallizing salt from seawaterChemical changes - ripening fruitNuclear changes - production of elements in the starsTherefore, matter/energy undergo changes.
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