I'm pretty sure it's A, but then again I'm only in 8th grade. Sorry if this doesn't help:(
What is the Ka of a 1.9 ~ 10-2 M
solution of carbonic acid (H2CO3)
with a pH of 3.88?
Ka = [ ? ] × 10!?)
Helllllp
Answer:
Ka = 9.2x10⁻⁷
Explanation:
The equilibrium of carbonic acid in water is:
H₂CO₃ ⇄ HCO₃⁻ + H⁺
Where Ka is defined as:
Ka = [HCO₃⁻] [H⁺] / [H₂CO₃]
The equilibrium concentration of the species is:
[H₂CO₃] = 1.9x10⁻² - X
[HCO₃⁻] = X
[H⁺] = X
As pH is -log[H⁺]
3.88 = -log[H⁺]
1.318x10⁻⁴ = [H⁺] = X
Replacing:
[H₂CO₃] = 1.9x10⁻² - 1.318x10⁻⁴ = 1.8868x10⁻²
[HCO₃⁻] = 1.318x10⁻⁴
[H⁺] = 1.318x10⁻⁴
Replacing in ka equation:
Ka = [1.318x10⁻⁴] [1.318x10⁻⁴] / [1.8868x10⁻²]
Ka = 9.2x10⁻⁷Answer: 9.2 x 10^-7
Explanation:
A scientist conducts a experiment to determine
Answer:
A scientist conducts an experiment to determine the rate of the following reaction: N2(g) + O2(g) ? 2NO(g)
Explanation:
help help please help me I need the answer ASAP
Solution A has a mass of 70g. Solution B has a mass of 35 g. when they are mixed, a chemical reaction occurs in which a gas is produced. if the mass of the final mixture is 90g, what mass of gas was produced???
Answer:
15 g
Explanation:
1. According to the Law of Conservation of Mass, the sum of the products should be 105 g because 70 g + 35 g = 105 g.
2. If 90g of solution was produced and there's supposed to be 105 g, then the remaining grams would be equal to the mass of the gas.
3. 105 g - 90g = 15 g
Which example is indirect evidence used to study Earth's interior?
O composition of minerals in a rock
age of a rock from within Earth
O location of an earthquake's epicenter
O texture of different core rock samples
Answer:
location of earthquakes epicenter
Explanation:
The location of an earthquake's epicenter is indirect evidence used to study Earth's interior. Therefore, option C is correct.
What is Earth's interior ?The Earth's interior is made up of four layers, three solid and one liquid—molten metal that is nearly as hot as the sun's surface. The deepest layer is a solid iron ball with a diameter of about 1,500 miles.
The Earth's core is significant for three reasons: (1) it generates the planet's magnetic field; (2) it contains information about the planet's early history of accretion; and (3) it contains information about the planet's earliest history of accretion.
Geologists use an indirect method as well. They use seismic waves instead of knocking on walls. Seismic waves are produced when earthquakes occur. Geologists study seismic waves and how they travel through the Earth.
Thus, option C is correct.
To learn more about the Earth's interior, follow the link;
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The mass of .10 moles of iron is:
Answer:
so mass in gram=560grams
Explanation:
number of moles=10moles
molar mass=56grams/moles
mass in gram of Fe=?
as we know that
[tex]number of moles=\frac{mass in gram}{molar mass}[/tex]
evaluating the formula
number of moles×molar mass=mass in gram
mass in gram=10moles×56grams/moles
mass in gram=560grams
i hope this will help you :)
How much energy does an X-ray with an 8 nm (8 x 10-9 m) wavelength have?
Answer: 2.48×10^-17 J
Explanation:
Given the following :
Wavelength = 8nm (8 x 10^-9 m)
Energy(e) of X-ray =?
Energy=[speed of light(c) × planck's constant (h)] ÷ wavelength
Speed of light = 3×10^8m/s
Planck's constant = 6.626×10^-34 Js
Wavelength = 8 x 10^-9 m
Energy = [(3×10^8) * (6.626×10^-34)] / 8 x 10^-9
Energy = [19.878×10^(8-34)] / 8 x 10^-9
Energy = 2.48475 × 10^(-26+9)
Energy = 2.48×10^-17 J
Answer: 2.48×10^-17 J
Explanation: a pex
Sulfuryl dichloride may be formed from the reaction of sulfur dioxide and chlorine. SO2(g) + Cl2(g) → SO2Cl2(g) Substance: SO2(g) Cl2(g) SO2Cl2(g) ΔH°f (kJ/mol) at 298 K –296.8 0 –364.0 ΔG°f (kJ/mol) at 298 K –300.1 0 –320.0 S°(J/K • mol) at 298 K 248.2 223.0 311.9 What is ΔG°rxn for this reaction at 600 K?
Answer:
ΔG°rxn = 28.4kJ/mol at 600K
Explanation:
Using Hess's law, you can find the ΔH°rxn and S° subtracting ΔH°f of products - ΔH°f of reactants ×its coefficients. In the same way for S°rxn
For example, for the reaction:
aA + bB → cC:
ΔH°rxn = c×ΔH°fC - (a×ΔH°fA + b×ΔH°fB).
S°rxn = c×S°fC - (a×S°fA + b×S°fB).
For the reaction:
SO₂(g) + Cl₂(g) → SO₂Cl₂(g)
ΔH°rxn = 1×ΔH°f{SO₂Cl₂} - (1×ΔH°fSO₂ + 1×ΔH°fCl₂).
S°rxn = 1×S°f{SO₂Cl₂} - (1×S°fSO₂ + 1×S°fCl₂).
As at 298K:
ΔH°f{SO₂Cl₂} = -364.0kJ/mol
ΔH°f{SO₂} = -296.8kJ/mol
ΔH°f{Cl₂} = 0kJ/mol
ΔH°rxn = 1×{-364.4kJ/mol} - (1×-296.8kJ/mol + 1×0).
ΔH°rxn = -67.2kJ/mol at 298K.
S°f{SO₂Cl₂} = 311.9J/molK
S°f{SO₂} = 248.2J/molK
S°f{Cl₂} = 223.0J/molK
S°rxn = 1×{311.9J/molK} - (1×248.2J/molK + 1×223.0J/molK).
S°rxn = -159.3J/molK = -0.159.3KJ/molK
Using:
ΔG°rxn = ΔH°rxn - S°rxn×T
Assuming ΔH°rxn doesn't change at 600K:
ΔG°rxn = -67.2kJ/mol - -0.159.3J/molK×600K
ΔG°rxn = 28.4kJ/mol at 600KDescribe how you could determine the specific heat of a sample of a solid substance. You may assume
at the substance does not react with water. In your answer, make sure to include a description of what
quipment you would use and how you would interpret the data you collected.
To calculate the actual heat, I'd use calorimetric to weigh a sample mass. I 'd calculate the mass of a material sample. At a specified temperature, I will heat the material. I should position the heated material inside a calorimeter for coffee cup containing an initially established mass of water. I 'd wait for the weather to stabilize and then measure the difference in weather. To assess the sum of energy consumed, I will use the increase in water temperatures. For measure real heat I will use the sum of energy per material, weight, and temperature shift.
-------------------------------
Hope this helps!
Brainliest would be great!
-------------------------------
With all care,
07x12!
Answer:
-I would use calorimetry to determine the specific heat.
-I would measure the mass of a sample of the substance.
-I would heat the substance to a known temperature.
-I would place the heated substance into a coffee-cup calorimeter containing a known mass of water with a known initial temperature.
-I would wait for the temperature to equilibrate, then calculate temperature change.
-I would use the temperature change of water to determine the amount of energy absorbed.
-I would use the amount of energy lost by substance, mass, and temperature change to calculate specific heat.
Planets near the Sun are composed of mainly rock and iron. How does the Solar Nebula theory account for this?
Answer:
The Solar Nebula Theory accounts for the creation of solar systems, stars, and planets. The theory accounts for planet composition by stating that iron compounds, silicates, and dust clump together to form planetesimals. Because of the proximity of the sun, ices and gases cannot condensate near them, so they do not become gas giants. The planetesimals then collide together due to gravity and collect to form our rocky planets.
Explanation:
What gas is used in freezers and fridges?
Answer:
Chloro-Flouro-Carbon
Explanation:
Chloro-Flouro-Carbon (CFC Gas) is used as a refrigerant in fridges and freezers.
The image below shows the Lake Mead Recreation Area,
which is near the Grand Canyon The diagram shows the
ages of layers of rock in one region of the park, The layers
at this location are fairly smooth and distinct
Private
What are these smooth, distinct layers most directly evidence of?
A Soll creep along the rocky cliffe
B. Many landslides and mudslides
6. Extensive chemical weathering
D. Many, many years of deposition
Answer:
D. Many, many years of deposition
Explanation:
The layers of the rocks in one region of the parks are smooth and distinct, which are evidence of many, many years of deposition.
The layers on the rocks are because of different deposition of sediments. Different sediments deposited over the rocks through wind, water and ice over the ages.
Hence, the correct answer is D.
Answer:
d
Explanation:
a pex
At what angle(s) should investigators photograph a tool mark? A. parallel B. perpendicular C. 45 degrees D. varying
Answer:
B
Explanation:
List 15 different things made of plastic in your house group them as thermoplastics and thermosetting plastics?
Answer:
Things made of thermoplastics
1) Plastic chairs
2) Plastic table
3) Plastic cups and plates
4) Nylon bags
5) Plastic cabinet
6) PVC pipes-
7) Internal electronic component such as gears
8) Vehicle dashboard
Things made of Thermosetting plastics
1) Electrical insulation
2) Handles of electrical fittings
3) Plastic hoses
4) Electric switch covering
5) Coverings of electronic gadgets
6) Silicone in adhesives
7) Keyboard
Explanation:
A plastic polymer material that becomes soft upon heating and hard once again when cooled such that the material can be repeatedly or cyclically cooled and heated numerous times with its chemical and physical properties remaining constant is known as a thermoplastic.
A plastic, polymer or resin that is hardened from its soft or liquid state by curing irreversibly such that it cannot be made soft again without a change in its chemical properties is known as a thermosetting plastic.
Which compound can be used to preserve biological specimens? A central C is double bonded to an O, and single bonded to 2 H. A chain, reading from left: C H 3 bonded to C, bonded to O, bonded to C H 2, bonded to C H2, bonded to C H 3. The single C near the beginning of the chain is double bonded to O. C H 3 single bonded to C, which is double bonded above right to O, and below right to C H 2, which is bonded to C H 3. A central C is double bonded to an O above, and single bonded to C H 3 below left and O H below right.
Answer:
A central C is double bonded to an O, and single bonded to 2 H
Explanation:
Methanal, also known as formaldehyde, is a chemical compound used to preserve dead biological specimens for further study. It is called formalin when in a solution and it helps keep specimens in a fresh state by hardening the tissues of the specimen involved.
Formaldehyde is a gaseous compound that has an aldehyde functional group i.e. -CHO and has a chemical formula, H-CHO or CH2O as described in the question that a central C is double bonded to an O, and single bonded to 2 H (see attached image for structural formula).
The chemical for the preservation of biological specimens has consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.
The biological compound that has been used to preserve biological specimens has been methanal. It has been the simplest aldehyde. The chemical formula of formaldehyde, also known as methanal has been H-CHO.
The structure of formaldehyde has been consisted with single bond between H and C. The central carbon has been associated with a double bond between the C and O, with single-bonded H.
Thus, the chemical for preservation of biological specimen has been consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.
For more information about the biological specimen, refer to the link:
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Which sequence represents the relationship between pressure and volume of an ideal gas as explained by the kinetic-molecular theory? more gas particles Right arrow. More collisions Right arrow. Higher pressure smaller volume Right arrow. Crowded particles Right arrow. Less collisions Right arrow. Lower pressure smaller volume Right arrow. Crowded particles Right arrow. More collisions Right arrow. Higher pressure more gas particles Right arrow. More kinetic energy Right arrow. More volume Right arrow. Higher pressure
Answer:
smaller volume ⇒ Crowded particles ⇒ More collisions ⇒ Higher pressure
Explanation:
Smaller the volume , more crowed the particles . Then the particles will have rapid collisions so the free mean path is decreased , hence the pressure will be increased as follows
[tex]P=\frac{K_bT}{\sqrt{2}\pi d^2\lambda }[/tex]
where λ is mean free path , P is pressure .
The sequence the represent the relationship between pressure and volume of an ideal gas is: smaller volume right arrow Crowded particles right arrow More collisions right arrow Higher pressure
The kinetic molecular theory made five postulates which are used to explain the behaviour of gases.
From the postulates, he uses the kinetic molecular theory to explain Boyle's Law because the majority of a gas's volume in space is usually empty and may be compressed.
So, when a gas is compressed without affecting its temperature, the average kinetic energy of the gas particles remains constant. The particles continue to flow at the same rate, but the container has reduced.
As a result, the particles go from one end of the container to another in less time. This suggests they're hitting the barriers (collision) more frequently. Each and every increase in the frequency of collisions with the walls, thus, results in an increase in the gas's pressure.
Hence, as the volume of a gas decreases, the pressure of the gas increases.
Learn more about the Kinetic molecular theory here:
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17.An element X on reacting with oxygen forms XO2. The oxide when dissolved in water turned red litmus blue. What will be the nature of ‘X’? Give reason for your answer.
Answer:
The oxide is basic, X must be a group two metal
Explanation:
The oxide XO2 must be an inorganic peroxide of a group two element. Inorganic peroxides of group two elements are highly basic because they dissolve in water to yield the corresponding metal hydroxides. These metal hydroxides are strongly basic solutions with a very high pH. Hence X may be Calcium, magnesium, barium, strontium or radium.
Group two metal peroxides include; CaO2, MgO2,BaO2 etc. They all dissolve in water to give corresponding basic solutions. For instance, calcium peroxide reacts with water as follows; CaO2 (s) + 2H2O(l) --------->Ca(OH)2(aq) + H2O2(aq). The production of Ca(OH)2 makes the solution basic. The hydrogen peroxide produced decomposes to water and oxygen.
draw a lewis structure for c2cl2 and indicate how many and what types of bonds are present
Answer:
B. 1 triple bond and 2 single bonds
Explanation:
C2Cl2 has linear structure.
For its Lewis structure, the C2Cl2 molecule has a total of 22 valence electrons. Each Carbon (C) atom has 4 valence electrons and 7 atoms in each chlorine atoms.
So, after pairing in C2Cl2, Chlorine (Cl) form 2 single bonds, one with each carbon atom andboth the Carbon (C) atoms form one triple bond with each other.
A sample of an ideal gas at 1.00 atm and a volume of 1.73 L was placed in a weighted balloon and dropped into the ocean. As the sample descended, the water pressure compressed the balloon and reduced its volume. When the pressure had increased to 70.0 atm, what was the volume of the sample
Answer:
Volume is 0.0247L
Explanation:
This question involves the use of Boyle's law which states that the volume of a given mass of gas is inversely proportional to it's pressure provided that temperature remains constant.
Mathematically,
v = k/p
K = VP
P1V1 = P2V2 = P3V3 = .........=PnVn
V = volume
p = pressure
Data;
P1 =1.0atm
V1 = 1.73L
P2 = 70atm
V2 = ?
P1V1 = P2V2
V2 = P1V1 / P2
V2 = (1.0×1.73)/70
V2 = 0.0247L
The volume of the sample is 0.0247L
A balloon has a volume of 0.56 L and a pressure of 1.34 atm. The balloons pressure decreased to 0.85 atm,
what is the balloons new volume? Write your solution, including the formula used.
Answer:
[tex]\large \boxed{\text{0.88 L}}[/tex]
Explanation:
The temperature and amount of gas are constant, so we can use Boyle’s Law.
[tex]p_{1}V_{1} = p_{2}V_{2}[/tex]
Data:
[tex]\begin{array}{rcrrcl}p_{1}& =& \text{1.34 atm}\qquad & V_{1} &= & \text{ 0.56 L} \\p_{2}& =& \text{0.85 atm}\qquad & V_{2} &= & ?\\\end{array}[/tex]
Calculations:
[tex]\begin{array}{rcl}\text{1.34 atm} \times \text{0.56 L} & =& \text{0.85 atm} \times V_{2}\\\text{0.750 L} & = & 0.85V_{2}\\V_{2} & = &\dfrac{0.750}{0.85}\\\\& = &\textbf{0.88 L}\\\end{array}\\\text{The balloon's new volume is $ \large \boxed{\textbf{0.88 L}}$}[/tex]
7.What is the chemical formula for Beryllium Nitride? *
Answer:
BE3N2
Explanation:
Which statement is correct about the rate of a chemical reaction? (5 points)
It increases when the concentration of reactants increases.
It does not depend on the concentration of reactants.
it increases when the temperature decreases.
It does not depend on the temperature.
Answer:
A) It increases when the concentration of reactants increases.
Explanation:
When you increase the concentration, there is more of a substance, and therefore more opportunities for the reactants to collide together with enough energy to create a product.
Answer:
A) It increases when the concentration of reactants increases.
Explanation:
It's just right!!!
You arrive at a crime scene and are told the body of the victim is in the 10 m deep pool. You walk over to what you are told is a 12 m in diameter, cylindrical pool. From the outside of the pool, you can see that the body looks badly burnt. Your partner says, “It looks like our victim had been burned alive and tried to put out the fire by jumping in the pool. The victim likely drowned to death.”
Something does not sit right with you though. If there was a fire, where did it start? There are no signs of combustion anywhere. You aren’t so sure and ask the crime scene investigator to run a sample of the pool water before letting anybody try to pull the body out.
The CSI comes back to you and tells you that normal pool water pH is roughly around 7.2, but the pool pH is actually highly basic at a level of 13 with a concentration of hydroxide ions at 1.0 x 10-1 mol/L. It becomes obvious to you that the body wasn’t burned before going in to the pool , but AFTER and there was no fire needed!
You order the body to be removed from the pool, but the CSI interjects, “It would be too dangerous with a pH that high. I suggest you get some vinegar from the store and pour it in to the pool before hand to drop the pH to 7. Draining the pool would take far too long and we need to examine the body as soon as possible.” She asks one of your constables to go to the store to purchase 5 – 4L jugs of vinegar (pH = 2) to pour in the pool, as she states it is enough to bring the pH to a safe level of 7.
It sounds like it could be enough vinegar based on your knowledge of acids and bases, but you want to double-check her estimate before sending your constable to the store. Verify whether or not she is correct using calculations. A diagram may help you with your calculations.
Hint 1: 1m3 = 1000L
Hint 2: Vcylinder = πr2h
Answer:
The vinegar is not enough to neutralize the pool.
Explanation:
The [OH⁻] in the pool is 1.0x10⁻¹mol / L. To know how many moles of OH⁻ are in the solution, you must calculate volume of the pool thus:
V(pool) = πr²h
Where r, radius is d/2 = 12m/2 = 6m and h is deep of the pool = 10m
V(pool) = π(6m)²*10
V(pool) = 1131m³
As 1m³ = 1000L:
1131m³ × (1000L / 1m³) = 1131000L in the pool.
And moles of OH⁻ are:
1.0x10⁻¹mol / L ₓ 1131000L = 131100 moles of OH⁻ are in the pool
The neutralization of OH⁻ with H⁺ is:
OH⁻ + H⁺ → H₂O
That means to neutralize the pool you must add 131100 moles of H⁺.
The H⁺ concentration in a vinegar pH = 2 is:
pH = -log [H⁺]
2 = -log [H⁺]
1x10⁻²M = [H⁺]
4L are just 4x10⁻² moles of [H⁺]. As you need 131100 moles of H⁺:
The vinegar is not enough to neutralize the pool.Can some one please explain?
1). Compared to the chemical oxidation of one atom of carbon, a nuclear fission reaction using one atom of uranium can yield about ____ times the energy output.
A)5
B)50
C)5000
D)5,000,000
2). In a nuclear fusion reaction, the total mass numbers of the reactants may equal the total mass numbers of the products. How can it still be true that mass is lost in nuclear fusion reactions?
A)In a nuclear fusion reaction, the fused nucleus is initially stable but then decays and loses mass.
B)The mass number is just an estimated mass measurement that is not precise.
C)The mass number only represents the total number of nucleons, which may be conserved.
D)In a nuclear fusion reaction, the products have greater kinetic energy than the reactants.
3). Nuclear fission reactions generally require:
A) small atomic nuclei to join together
B) large atomic nuclei to join together
C)small atomic nuclei to split apart
D)large atomic nuclei to split apart
Answer:
Explanation:
1 ) D)5,000,000
Compared to the chemical oxidation of one atom of carbon, a nuclear fission reaction using one atom of uranium can yield about 5000000____ times the energy output.
Energy in fission reaction comes from the conversion of mass into energy . This process results into creation of enormous amount of energy . But in the oxidation reaction of carbon , bonds are broken and new bonds are formed in which energy is used and released . The net energy released is difference of energy evolved minus energy used up . This difference is not much . Hence in such chemical reaction , energy released is not much .
2 ) B)The mass number is just an estimated mass measurement that is not precise.
In such calculation , the mass number used is just an estimated mass number and not the precise mass of particles involved . Hence , due to lack of precision in calculation , mass number appears to be constant . But actually there is decrease in mass in both fission and fusion reaction .
3 ) D
In fission reaction , large atomic nuclei splits into smaller nuclei to attain stability .
To increase the current in a circuit, which can be increased? A. voltage B. resistance C. interference D. ohms
Answer:
voltage I'm just guessing
Answer:
Option A
Explanation:
Looking at the following formula:
I = V/R
Where V is voltage, I is current and R is resistance
In the above equation, Current and Voltage are in direct relationship such that if I is increased , V is also increased and vice versa. So, To increase the current, voltage should be increased.
5.What is the chemibal formula for lead (II) iodide
Answer: The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]
Explanation:
Lead (II) iodide is a ionic compound because it are formed by transference of electrons between metals and non metals.The bond formed between a metal and a non-metal is always ionic in nature.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The nomenclature of ionic compounds is given by:
1. Positive is written first followed by the oxidation state of metal in roman numerals in square brackets.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]
What information did the scientists miss in 1948 and 1966 that caused them to
believe that the caps contained water ice?
Answer:
The information from Mariner 6 and Mariner 7
Explanation:
Because they had not been launched yet
Carbon monoxide (CO) reacts with hydrogen (H2) to form methane (CH4) and water (H20).
CO(g) + 3H2(g) + CH4(g)+H20(9)
The reaction is at equilibrium at 1,000 K. The equilibrium constant of the reaction is 3.90. At equilibrium, the concentrations are as
follows.
[CO] = 0.30 M
[H2] = 0.10 M
[H20] = 0.020 M
What is the equilibrium concentration of CH, expressed in scientific notation?
0.0059
5.9 x 10-2
0.059
5.9 x 102
Answer: The equilibrium concentration of [tex]CH_4[/tex] , expressed in scientific notation is [tex]5.9\times 10^{-2}M[/tex]
Explanation:
Equilibrium constant is the ratio of the concentration of products to the concentration of reactants each term raised to its stochiometric coefficients.
The given balanced equilibrium reaction is,
[tex]CO(g)+3H_2(g)\rightleftharpoons CH_4(g)+H_2O(g)[/tex]
At eqm. conc. (0.30) M (0.10) M (x) M (0.020) M
The expression for equilibrium constant for this reaction will be,
[tex]K_c=\frac{[CH_4]\times [H_2O]}{[CO]\times [H_2]^3}[/tex]
Now put all the given values in this expression, we get :
[tex]3.90=\frac{x\times (0.020)}{(0.30)\times (0.10)^3}[/tex]
By solving the term 'x', we get :
x = 0.059 M= [tex]5.9\times 10^{-2}M[/tex]
Thus, the concentrations of [tex]CH_4[/tex] at equilibrium is :
Concentration of [tex]CH_4[/tex] = (x) M = [tex]5.9\times 10^{-2}M[/tex]
The equilibrium concentration of [tex]CH_4[/tex] , expressed in scientific notation is [tex]5.9\times 10^{-2}M[/tex]
Answer:B
Explanation:B
If 56 J of heat is added to an aluminum can with a mass of 23.6 g , what is its temperature change? Specific heat capacity of aluminum is 0.903 J/g∘C.
Answer:
Q = mass x sph x temp change
temp change = Q/(mass x sph)
Temp change =57/(22 x .903)
Temp Change = 2.97 ∘C
Temp change 3.0 ∘C
or
We can use the heat equation,
Q = mcΔT
Where Q is the amount of energy transferred (J), m is the mass of the substance (g), c is the specific heat (J g⁻¹ °C⁻¹) and ΔT is the temperature difference (°C).
The given data
Q = 52 J
m = 28.4 g
c = 0.903 J g⁻¹ °C⁻¹
ΔT = ?
By applying the formula,
52 J = 28.4 g x 0.903 J g⁻¹ °C⁻¹ x ΔT
ΔT = 2.03 °C
Hence, the temperature change of aluminium during the heating process is 2.03 °C.
3.00g of glucose was burned in an excess of oxygen in bomb calorimeter with metal holder ("bomb") heat capacity of 2.21 kJ/oC. And 1.2kg of water where water has a specific heat capacity of 4.184 kJ/kgoC. The temp change upon combustion of glucose and oxygen was 19.0 0C to 25. 50C.Calculate the heat evolved from the combustion of 1.00 mol of glucose.
Answer:
THE HEAT EVOLVED FROM THE COMBUSTION OF 1 MOLE OF GLUCOSE IS - 2819.7 KJ/MOL OR -2.82 * 10^3 KJ/MOL OF HEAT.
Explanation:
Write out the variables given:
Mass of glucose = 3 g
Heat capacity of bomb calorimeter = 2.21 kJ /°C
Mass of water = 1.2 kg
Specific Heat capacity of water = 4.184 kJ/kg °C
Change in temperature = ( 25.50 °C - 19.0 °C ) = 6.5 °C
To calculate the heat evolved from the combustion of 1 mole of glucose, we do the following:
Equation for the reaction:
C6H1206 (s) + 6 02 (g)--------> 6 CO2 (g) + 6 H20 (l)
Calculate the total heat capacity involved in the system:
Heat capacity (Ctotal) = Heat capacity of the bomb calorimeter + heat capacity of water
Ctotal = 2.21 kJ/°C + (1.2 * 4.184 kJ/kg°C)
Ctotal = 7.2308 kJ°C
Next is to calculate the heat absoorbed by the calorimeter and water
Heat = Heat capacity (Ctotal) * change in temperature
Heat = 7.23 kJ/°C * 6.5 °C
Heat = 46.995 kJ
Hence, the amount of heat evolved when 3g of glucose was involved is 46.995 kJ
Since 1 mole of glucose reacts with 6 moles of oxygen to produce 6 moles of carbon dioxide and water respectively, then the amount of heat needed for the combustion of 1 mole of glucose is:
1 mole of glucose = (12 *6 + 1 * 12+ 16 *6) = 180 g/mol
From 3 g of glucose producing 46.995 kJ of heat
180 g of glucose will produce (180 * 46.995 / 3) kJ of heat
= 2819.7 kJ/mol of heat.
In conclusion, from the combustion of 1 mole of glucose, -2819.7 kJ/ mol of heat is evolved, since the heat was evolved or liberated.
I really need help with these chemistry questions pleasee
Answer:
The answer to your question is given below
Explanation:
8. The equation for the reaction is given below:
Mg3N2 + H2O –> Mg(OH)2 + NH3
Number of reactant atoms before balancing:
Mg = 3
N = 2
H = 2
O = 1
Number of product atoms before balancing:
Mg = 1
N = 1
H = 5
O = 2
Now, let us balanced the equation.
Mg3N2 + H2O –> Mg(OH)2 + NH3
There are 3 atoms of Mg on the left side and 1 atom on the right side. It can be balance by putting 3 in front of Mg(OH)2 as shown below:
Mg3N2 + H2O –> 3Mg(OH)2 + NH3
There are 2 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 2 in front of NH3 as shown below:
Mg3N2 + H2O –> 3Mg(OH)2 + 2NH3
There 2 atoms of H on the left side and a total of 12 atoms on the right side. It can be balance by putting 6 in front of H2O as shown below:
Mg3N2 + 6H2O –> 3Mg(OH)2 + 2NH3
Now the equation is balanced.
Number of reactant atoms after balancing:
Mg = 3
N = 2
H = 12
O = 6
Number of product atoms after balancing:
Mg = 3
N = 2
H = 12
O = 6
9. When methane react with steam, carbon dioxide and hydrogen gas are produced as shown below:
CH4 + H2O –> CO + H2
Now, let us balance the equation. This is illustrated below:
There are a total of 6 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 3 in front of H2 as shown below:
CH4 + H2O –> CO + 3H2
Now the equation is balanced.