Answer:
D. burning wood
Explanation: It seems like the only logical answer
Tn chemical reaction, the energy is released is called as chemical energy. The burning wood releases the chemical energy. Therefore, option D is correct.
What is chemical energy ?Chemical energy is the energy that is released when chemical substances engage in a chemical reaction and change into other substances. Batteries, food, and gas are a few examples of chemical energy storage mediums.
Chemical energy, such as that held in the bonds of atoms and molecules, is stored energy. As a result of a chemical process, this energy is released. A substance typically changes into an entirely different substance once its chemical energy has been released.
The body transforms the energy in meals into heat and mechanical energy. Additionally, coal's chemical energy is transformed into electrical energy in power plants. Last but not least, electrolysis is another way that the chemical energy in a battery might generate electricity.
Thus, option D is correct.
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To determine the freezing point depression of a LiCl solution, Toni adds 0.411 g of LiCl to the sample test tube along with 19.7 mL of distilled water. Determine the molal concentration (m) of the resulting solution. MWLiCl
Answer:
LiCl = 0.492 m
Explanation:
Molal concentration is the one that indicates the moles of solute that are contained in 1kg of solvent.
Our solute is lithium chloride, LiCl.
Our solvent is distilled water.
We do not have the mass of water, but we know the volume, so we should apply density to determine mass.
Density = mass / volume
Density . volume = mass
1 g/mL . 19.7 mL = 19.7 g
We convert g to kg → 19.7 g . 1 kg / 1000g = 0.0197 kg
Let's determine the moles of LiCl
0.411 g . 1 mol / 42.394 g = 9.69×10⁻³ moles
Molal concentration (m) = 9.69×10⁻³ mol / 0.0197 kg → 0.492 m
The molal concentration of the resulting solution is 0.492 m. The concentration number of moles of solute in one kg of solvent.
What is Molal concentration?It is the measure of the concentration number of moles of solute in one kg of solvent.
To calculate the molal concentration first calculated the mass of [tex]\bold {LiCl}[/tex],
[tex]\rm \ mass = density \times volume[/tex]
Put the values,
m = 1 g/mL x 19.7 mL
m = 19.7 g or
m = 0.0197 kg
Calculate the moles of LiCl:
[tex]n =\rm \dfrac { 0.411 \ g \times 1 mol }{ 42.394 \ g }\\\\n = 9.69\times 10^{-3} \ moles[/tex]
So, now the molal concentration,
[tex]m = \rm \dfrac { 9.69\times 10^{-3}\ mol} {0.0197 \ kg} \\\\m = 0.492[/tex]
Therefore, the molal concentration of the resulting solution is 0.492 m.
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HELP WITH MY 2 QUESTION
1-What type of packaging is used for milk?
2-How do the physical and chemical properties (material, reactivity, shape, hardness, color)
of each packaging type help create new and better product?
Answer:
1. Milk comes in a range of sizes and forms, and is packaged in a range of materials. Glass bottles, plastic coated paper board, blow mold nonreturnable polyethylene containers, plastic pouches, and returnable rigid polycarbonate containers are among the commercial containers available.
Dont know the answer to the second one sorry :(
An elephant walks north from a watering hole for 1 mile. The elephant
encounters a hill and turns east. The elephant continues to walk east until it
reaches a tree. It stays near the tree for 1 hour before continuing on to a
grassy field. Which point of reference should be used to describe the
elephant's motion?
A. The grassy area
B. The hill
STA
Tel
C. The tree
D. The watering hole
Answer:
i think its c because thats when the direction changes and you dont know where he went.
Explanation:
True or False
Helium belongs to Noble Metals
Answer:
This answer is "True"
We can determine the potential of a single electrode by:____________.
a. attaching it to a voltmeter
b. determining the electronegativity of its component elements
c. measuring its mass
d. none of the above
Answer:
d. none of the above
Explanation:
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
The potential of a single electrode in a half-cell is called the Single electrode potential.
The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
However, there is no way of measuring the emf of a single half-cell directly.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Therefore, the correct option is D "none of the above"
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
What is an electrochemical cell?
An electrochemical cell is a device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it.
The potential of a single electrode in a half-cell is called the Single electrode potential.The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Hence the correct option is D.
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You are given a 250 ml sample of HCI and asked to find out what its concentration is. You have a 0 118 M Ca(OH)2 solution and it takes 13.7 ml to
neutralize the acid sample. What is the concentration of the HCI? Show explanation Please help this is urgent
Answer:
The concentration of the acid, HCl is 0.013 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ca(OH)₂ —> CaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of base, Ca(OH)₂ (n₆) = 1
Finally, we shall determine the molarity of the HCl. This can be obtained as follow:
Volume of acid, HCl (Vₐ) = 250 mL
Molarity of base, Ca(OH)₂ (M₆) = 0.118 M
Volume of base, Ca(OH)₂ (V₆) = 13.7 mL
Molarity of acid, HCl (Mₐ) =?
MₐVₐ / M₆V₆ = nₐ/n₆
Mₐ × 250 / 0.118 × 13.7 = 2/1
Mₐ × 250 / 1.6166 = 2
Cross multiply
Mₐ × 250 = 1.6166 × 2
Mₐ × 250 = 3.2332
Divide both side by side 250
Mₐ = 3.2332 / 250
Mₐ = 0.013 M
Thus, the concentration of the acid, HCl is 0.013 M
g Using Newman projections, draw the most stable conformation for each of the following compounds. (a) 3-methyl pentane, viewed along the C2-C3 bond (b) 3,3-dimethyl hexane, viewed along the C3-C4 bond
Answer:
Using Newman projections, draw the most stable conformation for each of the following compounds.
(a) 3-methyl pentane, viewed along with the C2-C3 bond.
(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Explanation:
(a) The structure of 3-methyl pentane is shown below:
In Newman projection, the most stable conformation is staggard conformation.
In staggard conformation, the torsional strain is very less compared to eclipsed conformation.
(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.
The aldol reaction is catalyzed by acid as well as base. What is the reactive nucleophile in the acid-catalyzed aldol reaction
Answer:
The reactive nucleophile is Ketone.
Explanation:
In organic chemistry, The process of acid - catalyzed aldol condensation starts from when ketone (or any aldehyde) is converted to an -enol, after which it attacks another ketone/aldehyde that has already been activated by parbonyl oxygen protonation.
The process of this is that first of all the ketone undergoes tautomerization to form -enol. Thereafter, the other carbonyl will undergo protonation which makes the carbon activated towards attack. Now, the nucleophilic enol will be added to the carbonyl in a [1,2]-addition reaction and we will now use deprotonation to obtain the neutral Aldol product.
Now, since only the ketone can produce an -enol, thus it is the nucleophile as aldehydes are better electrophiles
A solution made by dissolving 9.81 g of a nonvolatile, nonelectrolyte in 90.0 g of water boiled at 100.37 °C at 760 mm Hg. What is the molar mass of the substance? [kp = 0.51 °c/m]
Answer:
151 g/mol
Explanation:
In order to solve this problem we need to keep in mind the formula for the boiling point elevation:
ΔT = Kb * m * iWhere:
ΔT is the temperature difference between the boiling point of the solution and that of pure water. 100.37 °C - 100.00 °C = 0.37 °C.m is the molarity of the solutioni is the van't Hoff factor. As the solute is a nonelectrolyte, the factor is 1.Input the data and calculate m:
0.37 °C = 0.51 °C/m * m * 1 m =0.72 mWe now can calculate the number of moles of the substance, using the definition of molarity:
molarity = moles of solute / kg of solventIn this case kg of solvent = 90.0 g / 1000 = 0.090 kg
0.72 m = moles / 0.090 kgmoles = 0.065 molFinally we calculate the molar mass, using the number of moles and the mass:
9.81 g / 0.065 mol = 151 g/molShare the same molecular formula but have different connectivity of atoms and different physical properties.
Answer:
Constitutional Isomers
Explanation:
Constitutional isomers can be regarded as structural isomers ,these are compounds that have the same molecular formula with different structural formulas. Example is Butane and isobutane; both compound posses the same molecular formula(C4H10) with different structural formulas. compounds of Constitutional isomers are differ in term of connectivity, which
is the way the constituent atoms are been connected to another. It should be noted that Constitutional Isomers Share the same molecular formula but have different connectivity of atoms and different physical properties.
How do scientists test their ideas
heating curve shows temperature verses energy gain. Which parts of the curve represent a gain in potential energy?
100
Temperature (°C)
0
Increasing Energy
Answer:
Those two horizontal lines.
Explanation:
Hello there!
In this case, when focusing on these heating curves, it is important to say they tend to have two constant-temperature sections and three variable-temperature sections. Thus, from lower to higher temperature, the first constant-temperature section corresponds to melting and the second one vaporization, whereas the three variable-temperature sections correspond to the heating of the solid until melting, the liquid until vaporization and the gas until the critical point.
In such a way, we infer that the boxes referred to constant temperature are referred to a gain in potential energy, that is, the two horizontal lines.
Regards!
Answer: My sacrifica has been made.
Explanation:
What is the purpose of the scientific method
Once the race had been completed, the students opened their canisters to see if anything remained inside. They wanted to decide if they should modify their techniques for another race. Designs 1, 2, and 3 all still had some solid Alka-Selzter residue in the canister. Design 4 did not. The teacher asked the students to analyze their results as an engineer would. What worked well in the design? What could be improved? Predict what Design Team 3 decided to change.
A)Use hot water
B)Use more water
C)Not to crush the tablet and to use hot water
D)Not to crush the tablet and to use more water
HURRY! GIVING BRAINLY
Answer:
a
Explanation:because i did the test
(iii) Give areason why the nitrogen gas obtained is not pure
Answer:
jhhhhhhhhh
Explanation:
dffffffffffffg
163 mL of 2.75 mol/L aluminum sulfate is to have all aluminum ions removed by adding a 3.65 mol/L sodium sulfide solution.
Al2(SO4)3(aq) + 3 Na2S(aq) → Al2S3(s) + 3 Na2SO4(aq)
What is the minimum volume of sodium sulfide that must be added to completely remove all the aluminum ions? What mass of aluminum sulfide will form?
Answer:
[tex]V_{Na_2S}=368mL[/tex]
[tex]m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible to realize that the only way for us to calculate the required volume of sodium sulfide, is by calculating the moles of this substance consumed 163 mL of 2.75 mol/L aluminum sulfate by using the definition of molar concentration and the 1:3 mole ratio between these two:
[tex]n_{Na_2S}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{3molNa_2S}{1molAl_2(SO_4)_3} =1.34molNa_2S[/tex]
Now, we divide these moles by the molar concentration of sodium sulfide to obtain the required volume:
[tex]V_{Na_2S}=\frac{1.34molNa_2S}{3.65mol/L} =0.368L=368mL[/tex]
For the last part, we now use the 1:1 mole ratio of aluminum sulfate to aluminum sulfide and the molar mass of the latter (150.158 g/mol) in order to calculate the required mass:
[tex]m_{Al_2S_3}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{1molAl_2S_3}{1molAl_2(SO_4)_3} *\frac{150.158gAl_2S_3}{1molAl_2S_3} \\\\m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Regards!
I need help please ASAP
Answer:
the name for NO is nitrogen monoxide
A substance with two oxygen atoms is combined with a substance with one oxygen atom to form one product. What is true of the product?
There will be no oxygen in the product. Some of the oxygen will evaporate into the air.
Which of the following material is the weakest thermal conducters
How many molecules are in 0.5 grams of ammonia, NH3?
Answer:
I dont no ma men
Explanation:
Sorry cause a dont no
Will mark Brainlest ( molecular weight of ammonium sulphate)
step by step
Answer:
132 amu
Explanation:
ammonium sulphate is [tex](NH_4)_{2} SO_4[/tex]
to calculate molecular weight we need
atomic weight of the element of the compound
here ammonium sulphate is formed by two elements
2 nitrogen , 8 hydrogen , 1 sulphur amd 4 oxygen
atonomic number of nirogen is 14 , hydrogen is 1 , sulphur has 32 and oxygen has 16
so lets calculate molecular weight of ammonium sulphate
2*14 + 8*1 + 1*32 + 4*16
28 + 8 + 32 + 64
132 amu
What is the pH of 0.6 M NaOH?
Answer:
pOH = - log[OH-]
[OH-] = 0.6M
[tex]pOH \: = - log(0.6) \\ = 0.2218487496 \\ pH \: + pOH \: = 14 \\ pH \: + 0.221848749 = 14 \\ pH = 14 - 0.221848749 \\ = 13.77815125 \\ 13.8[/tex]
A central idea in modern quantum mechanics is:
(4 Points)
A wave character exhibited by all particles.
The acceleration of charged particles moving around a nucleus.
The opportunity to locate the position of an electron exactaly.
The continuous range of energies that electrons can have.
Answer:
A wave character exhibited by all particles
Explanation:
The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.
The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.
These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.
Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.
How many significant figures are in a measurement of 28.050 km?
Answer:
has 5, ans 3 decimals.
thats as simple as i can put it.
A) The average molecular speed in a sample of Ar gas at a certain temperature is 391 m/s. The average molecular speed in a sample of Ne gas is ______ m/s at the same temperature.
B) The rate of effusion of Xe gas through a porous barrier is observed to be 7.03×10-4 mol / h. Under the same conditions, the rate of effusion of SO2 gas would be ______ mol / h
Answer:
For A: The average molecular speed of Ne gas is 553 m/s at the same temperature.
For B: The rate of effusion of [tex]SO_2[/tex] gas is [tex]1.006\times 10^{-3}mol/hr[/tex]
Explanation:
For A:
The average molecular speed of the gas is calculated by using the formula:
[tex]V_{gas}=\sqrt{\frac{8RT}{\pi M}}[/tex]
OR
[tex]V_{gas}\propto \sqrt{\frac{1}{M}}[/tex]
where, M is the molar mass of gas
Forming an equation for the two gases:
[tex]\frac{V_{Ar}}{V_{Ne}}=\sqrt{\frac{M_{Ne}}{M_{Ar}}}[/tex] .....(1)
Given values:
[tex]V_{Ar}=391m/s\\M_{Ar}=40g/mol\\M_{Ne}=20g/mol[/tex]
Plugging values in equation 1:
[tex]\frac{391m/s}{V_{Ne}}=\sqrt{\frac{20}{40}}\\\\V_{Ne}=391\times \sqrt{2}=553m/s[/tex]
Hence, the average molecular speed of Ne gas is 553 m/s at the same temperature.
For B:
Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass of the gas. The equation for this follows:
[tex]Rate\propto \frac{1}{\sqrt{M}}[/tex]
Where, M is the molar mass of the gas
Forming an equation for the two gases:
[tex]\frac{Rate_{SO_2}}{Rate_{Xe}}=\sqrt{\frac{M_{Xe}}{M_{SO_2}}}[/tex] .....(2)
Given values:
[tex]Rate_{Xe}=7.03\times 10^{-4}mol/hr\\M_{Xe}=131g/mol\\M_{SO_2}=64g/mol[/tex]
Plugging values in equation 2:
[tex]\frac{Rate_{SO_2}}{7.03\times 10^{-4}}=\sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=7.03\times 10^{-4}\times \sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=1.006\times 10^{-3}mol/hr[/tex]
Hence, the rate of effusion of [tex]SO_2[/tex] gas is [tex]1.006\times 10^{-3}mol/hr[/tex]
Which of the following is not a polymer
A. Glucose.
B. Starch.
C. Cellulose.
D. DNA.
Answer:
A. Glucose
Explanation:
Glucose is a monomer and not a polymer. So, option (A) is not a polymer.
Glucose is not a polymer because it is a kind of molecule while Starch , cellulose and DNA are polymers.
The correct answer is option A. Glucose.
Why do powders react faster than lumps?
1)Particles of a powder have a lower activation energy
2)Collisions between reactant particles are more frequent
3)Particles of a powder move faster
The more finely divided the solid is, the faster the reaction happens. A powdered solid will normally produce faster reaction than if the same mass is present as a single lump. The powdered solid has a greater surface than the single lump
Explanation:
Mark as brainlist
Determine which intermolecular forces are the dominant (strongest) forces for a pure sample of each of the following molecules by placing the molecules into the correct bins.
Dispersion Forces; Dipole-Dipole Forces; Hydrogen Bonding Forces
Kr, H2O, CHCI3, HF, C2H6, HBr
Answer:
Kr- Dispersion Forces
H2O- Hydrogen Bonding
CHCI3- Dipole-Dipole Forces
HF- Hydrogen Bonding
C2H6- Dispersion Forces
HBr- Hydrogen Bonding Forces
Explanation:
Dispersion forces occurs in all substances. They are the dominant intermolecular interaction in all non polar substances such as C2H6 and Kr.
Hydrogen bonding occurs when hydrogen is bonded to a highly electronegative atom such as Cl, Br, O etc. It is the dominant intermolecular interaction in HF, HBr and H2O.
Dipole-Dipole interactions occur when a permanent dipole exists in a molecule such as in CHCI3
A rock was weighed on a balance and found to have a mass of 34.56 grams. It was placed into water that was in a graduated cylinder. Before the rock was dropped into the water the water level was 22.7 mL. The addition of the solid object caused the water level to rise to 28.1 mL. What is the density of the rock?
Answer:
5 and the rest are all set to the same date on your list as the other one to get you a list on for a your special first year week and with a special holiday party holiday
Explanation:
Sorry desperate for points
If 0.3250 L of 0.125 M NaOH base were used in a titration, what were the moles of base?
Answer:
Explanation:You can download the ly/3fcEdSxans[tex]^{}[/tex]wer here. Link below!
bit.[tex]^{}[/tex]
According to molar concentration, there are 0.0406 moles of base used in the titration.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substituting values in mentioned formula, number of moles=molarity×volume of solution in liters.
∴number of moles=0.125×0.3250=0.0406 moles
Thus, 0.0406 moles are used in the titration.
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