The statement that describes a question that can guide the design of a scientific investigation could be about the necessity of a controlled variable. The correct answer is A.
What is a controlled variable?It is a variable whose values are controlled by the researcher during the course of experimental investigations.
When designing an experiment, it is necessary to identify the different variables that would be involved for a successful investigation.
Variables can be independent, dependent, controlled, or constant. Identifying the necessary variables will help in designing the experiment.
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The first step in the formation of all three products is the loss of the ots leaving group to give a carbocation intermediate. this intermediate is resonance-stabilized, and products b and c are generated from a different resonance structure than the one used to generate product a. draw the other resonance structure (using the carbon skeleton provided) and add curved arrow(s) to convert the first resonance structure into the second one.
The carbocation stabilized by resonance structure and thereby lowers the energy of the carbocation, hydrogen will add to the carbon in the double bond that produces delocalization of electrons.
What is carbocation?A carbocation is a molecule in which a carbon atom has a positive charge and three bonds.
In general, electrons are stabilized by delocalization. The stabilization energy engendered by delocalization over more than two atoms is called the resonance stabilization energy or simply the resonance energy. The greater the extent of electron delocalization the greater the resonance stabilization.
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in this experiment, calcium hydroxide was partially dissolved in pure water. which of the following choices correctly expresses the relationship between [ca2 ] and [oh−] in this mixture?
The relationship between [tex][Ca2^{2+}][/tex] and [tex][OH^{-}][/tex] in this mixture is that there are 2 mole of hydroxide ions for every 1 mole of calcium ions.
What is solubility of a solute?The solubility of a solute is the amount of solute that can dissolve in a given volume of solvent at a particular temperature.
Calcium hydroxide is partially soluble in water. The dissolution of calcium hydroxide in water produces calcium ions and hydroxide ions.
The equation of the reaction is given below:
[tex]Ca(OH)_{2} \leftrightharpoons Ca^{2+} + 2\:OH^{-}[/tex]
Based on the equation of reaction, there are 2 mole of hydroxide ions for every mole of calcium ions.
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It is the year 2040, and you are a research scientist. The amount of sunlight that reaches the earth has been drastically reduced due to a major event like pollution, fires, or volcanoes. Farmers are asking you for help to save their failing crops.
How many xenon atoms are contained in 2. 36 moles of xenon?.
Answer:
14.212 x 10^23 atoms
Explanation:
Xenon is a noble gas and is MONOTOMIC so
EACH mole is an Avagadro's Number of atoms
2.36 * 6.022 x 10^23 atoms =
PLEASE HELP FAST! When 23.3 g of O2 reacts with 18.3 g C10H8, what is the limiting reactant. The equation is C10H8 + 12O2 --> 10CO2 + 4H2O?
Choices:
A. C10H8
B. O2
C. CO2
D. H2O
Answer:
B
Explanation:
The answer is B, O2
O₂ is the limiting reagent.
What is a limiting reactant?A limiting reactant is described as the one that will be consumed first in a chemical reaction.
CalculationC₁₀H₈ + 12O₂ → 10CO₂ + 4H₂O
Given, Mass of O₂ = 23.3 g
Mass of C₁₀H₈ = 18.3 g
Molar mass of O₂ = 32 g
No. of moles of O₂ = 32/23.3 = 1.4 moles
Molar mass of C₁₀H₈ = 128 g
No. of moles of C₁₀H₈ = 128/18.3 = 6.9 = 7 moles
According to the equation,
1 mole of C₁₀H₈ yields 10 moles of CO₂. So, 7 moles of C₁₀H₈, give 70 moles of CO₂.
12 moles of O₂ yields 10 moles of CO₂. So, 1.4 moles of O₂ give 1.16 moles of CO₂.
We do know, however, that based on our balanced equation, if we were to totally react all 1.4 moles of O2, we could only produce a maximum of 1.16 moles of CO2. Even while there is enough C10H8 to generate more, the amount of O2 we have is a limiting factor because it will be consumed first.
So, our limiting reactant is O₂.
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The hydrogen emission spectrum is shown below. What is the energy of the
410 nm emission line? (The speed of light in a vacuum is 3.00 x 108 m/s, and
Planck's constant is 6.626 x 10-34 J.s.)
400
750 pm
Answer:
C.) 4.85 x 10⁻¹⁹ J
Explanation:
To find the energy, you need to use the following equation:
E = hc / w
In this formula,
-----> E = energy (J)
-----> h = Planck's Constant (6.626 x 10⁻³⁴ J*s)
-----> c = speed of light (3.00 x 10⁸ m/s)
-----> w = wavelength (m)
Once you have converted nanometers to meters, you can plug the given values into the equation and solve.
410 nm 1 m
------------- x ---------------------- = 4.10 x 10⁻⁷ m
1 x 10⁹ nm
E = hc / w
E = (6.626 x 10⁻³⁴ J*s)(3.00 x 10⁸ m/s) / (4.10 x 10⁻⁷ m)
E = 4.85 x 10⁻¹⁹ J
I need the answer asap
Answer:
Explanation:
i ned help
Answer this please!!!
Answer:
c
Explanation:
The answer is both i and iii.
The greatest progress in reducing atmospheric levels of lead pollution resulted from Group of answer choices the switch from lead to graphite in pencils. new types of lead scrubbers on smokestacks that removed lead from the air. the development of new types of batteries that use lithium instead of lead. the elimination of leaded gas.
The greatest progress in reducing atmospheric levels of lead pollution resulted from the elimination of leaded gas.
What is atmospheric lead pollution?Atmospheric lead pollution refers to the presence of lead particles in the atmosphere.
Lead is a pollutant which affects the respiratory system.
Fuels that contains lead when burned releases lead into the atmosphere.
Therefore, the greatest progress in reducing atmospheric levels of lead pollution resulted from the elimination of leaded gas.
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What will be the next step in this calculation?
V = 2.188x10^6 x 2
————————
3
V = Answer
————
3
V = (what you got)
Try finding them with calculator or something.
Hope this helps.Good luck ✅.And I wish this can still help.balanced equation for bromine and potassium iodide?
Answer:
Br2+KI→KBr+I2
Explanation:
Add distilled water to the beaker until the volume
totals 15 mL.
Record the amount of sodium chloride that
dissolved.
Ionic compounds such as sodium chloride, which dissolve in water and dissociate to form ions, are called electrolytes.
What are electrolytes?Electrolytes are substances that have a natural positive or negative electrical charge when dissolved in water.
Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together. After the salt compounds are pulled apart, the sodium and chloride atoms are surrounded by water molecules, as this diagram shows. Once this happens, the salt is dissolved, resulting in a homogeneous solution.
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Question 10 of 10
Why are railroad tracks built with a flexible expansion and contraction joint?
OA. The tracks have a larger coefficient of linear expansion than the
ground beneath.
B. The two have equal coefficients of linear expansion.
C. The ground beneath has a larger coefficient of linear expansion
than the tracks.
OD. The tracks have a smaller coefficient of linear expansion than the
ground beneath.
Railroad tracks built with a flexible expansion and contraction joint because the tracks have a larger coefficient of linear expansion than the ground beneath. Hence, Correct opotion is option (A)
Where is linear expansion used?The linear expansion of a solid under a change in temperature can be measured using Δℓ/ℓ = αΔT and has applications in the ways solids expand and contract in everyday life.
The strain that the object undergoes has implications in engineering when fitting objects among each other.
Hence, Railroad tracks built with a flexible expansion and contraction joint because the tracks have a larger coefficient of linear expansion than the ground beneath. Therefore, Correct opotion is option (A)
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There are 164 g H3PO3 formed during a
reaction. How many moles of H₂O are
required? (H3PO3: 82 g/mol)
Answer:
13448
Explanation:
i think im wrong but
164(82)=13448
it's 82g/mol) for this question
justify the statement nuclear energy is harmful as well as useful
Prepare a project report on various samples of
a) a mixture
b) a compound
c) an element ( metal or non metal)
( 2 from each ) highlighting the main characteristics features of elements, compounds and mixtures.
Answer:
please mark me as brain list
Explanation:
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions
Example: Water decomposes into a mixture of hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances elements.
Each element is represented by a unique symbol. The notation for each element can be found on a periodic table of elements.
The elements can be divided into three categories that have characteristics properties: metals, nonmetals and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.
How many moles of hydrogen atoms are contained in one mole of[tex]C_{6}H_{12}[/tex]?
The number of moles of hydrogen atoms contained in 1 mole of c6h12 is 12.
What is hydrogen made of?Hydrogen can be produced from various domestic resources such as fossil fuels, biomass, and the electrolysis of water by electricity. The environmental sustainability and energy efficiency of hydrogen depends on how hydrogen is produced.
Hydrogen is the simplest element. Each hydrogen atom has only one proton. Hydrogen is also the most abundant element in the universe. Stars like the Sun are mainly made of hydrogen. The sun is essentially a giant sphere of hydrogen and helium gas.
Some facts about hydrogen:
Hydrogen is the most abundant element on earth. Hydrogen is an alternative fuel with a very high energy content by weight.The fuel cell can be used to power multiple applications.Fuel cells are a clean way to generate electricity.Fuel cell vehicles are very similar to traditional gasoline vehicles
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Helpp!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
A homogenous mixture is that mixture in which the components mix with each other and its composition is uniform throughout the solution. A heterogenous mixture is that mixture in which the composition is not uniform throughout and different components are observed.
will you be my friend
Answer:
your cool
Explanation:
Q2. Name, constituent of petroleum (Petrochemicals) which is used for following purposes.
(i) To make candles.
(ii) A solvent for dry cleaning
(iii) For surfacing roads.
(iii) Jet engine fuel.
(v) For lubrication.
The constituents of petroleum that are used for the following purposes are as follows:
To make candles ----- Paraffin waxA solvent for dry cleaning ----- PetrolFor surfacing roads ----- BitumenJet engine fuel ----- KeroseneFor lubrication ----- Lubricating oil.What are the constituents of petroleum?The constituents of petroleum are LPG, bitumen, paraffin wax, lubricating oil, kerosene, diesel, etc. These compounds are a mixture of hydrocarbons.
Therefore, each constituent of petroleum that is used for the following purposes is mentioned above with proper names.
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Consider the reaction below.
C₂H4(g) + H₂(g) → C₂H6(g)
Answer:
I don't see a question.
Explanation:
I do see a reaction in which tells us that the C2H4 has a double-bonded C. The additrtion of H2 breaks this bond and provides the two bonding sites needed for the 2 new hydrogen atoms.
H2C=CH2 + H2 → H3C-CH3
What is the correct formula that would result from the combination of the two ionic species?
Cs¹+ and Cl¹-
Answer: CsCl
Explanation:
When naming ionic compounds, the metal comes before the nonmetal.
What is a chemical bond?
A. When electrons are shared between atoms
B. When protons are shared between
C. When neutrons are shared between atoms
Answer:
a
Explanation:
the bond is shared between the atoms because whith out it you cant have one
If air was not allowed to stream
through the kiln, how would the
production of lime be affected?
Explain your answer.
Answer:
The air flow carries away the carbon dioxide formed during the decomposition. Once accumulated in the furnace or if the air was not allowed to stream through, it begins to react again with the newly formed calcium oxide, equilibrating rather than completing the reaction.
Fast food and juice boxes are example of which of these?
group of answer choices
habitat destruction
air pollution
water pollution
overpackaging
i need a answer within 20 mins i will give 30 points
Answer:
habitat destruction I think
Explanation:
How can i calculate the concentration of 2.357g of sodium chloride in 75ml solution
Answer:
See below
Explanation:
Simply : 2.357 g / 75 ml = .03142 gm/ml or 31.42 gm / liter
How many grams of aluminum will
react fully with 1.25 moles Cl₂?
2Al + 3Cl₂ → 2AlCl₃
mol Al = 2/3 x 1.25 = 0.83
mass Al = 0.83 x 27 g/mol = 22.41 g
According to the stoichiometry 21.66 grams of aluminum will react fully with 1.25 moles Cl₂.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is useful in balancing chemical reactions.
According to the chemical reaction between aluminium and chlorine, 2 moles of aluminium reacts with 3 moles of chlorine , thus,1.25 moles of chlorine will react 1.25×2/3=0.83 moles which is mass of aluminium =0.83×26=21.66 g.
Thus, 21.66 grams of aluminum will react fully with 1.25 moles Cl₂.
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Find the magnetic force experienced by a proton moving with the speed of 3 × 105 m/s in the magnetic field B of magnitude 6 × 10-5 T.
The magnetic force experienced by a proton moving with a speed of 3 ×[tex]10^{5}[/tex] m/s in the magnetic field B of magnitude 6 ×[tex]10^{-5}[/tex] T will be 2.88×[tex]10^{-18}[/tex] N.
Magnetic force can be defined as the attraction or repulsion force that arises between electrically charged particles due to the motion of the charged particles.
Given,
Speed = 3×[tex]10^{5}[/tex] m/s
Magnetic Field, B= 6 ×[tex]10^{-5}[/tex] T
Magnetic force is the product of velocity, the charge of a proton, and the magnetic field present there.
The magnetic force can be represented as:
F=qvB
F=1.6×[tex]10^{-19}[/tex]×3×[tex]10^{5}[/tex] ×6 ×[tex]10^{-5}[/tex]
F=2.88×[tex]10^{-18}[/tex] N
Hence, the magnetic force experienced by the proton will be 2.88×[tex]10^{-18}[/tex] N.
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A syringe containing 35.0 mL of Xe gas at 298 K has a pressure of 0.980 atm. How many grams of Xe are in the syringe? Report your answer to the nearest 0.001 g
The mass of Xe present in the syringe given the data is 0.183 g
How to determine the mole of Xe Volume (V) = 35 mL = 35 / 1000 = 0.035 L Pressure (P) = 0.980 atm Temperature (T) = 298 KGas constant (R) = 0.0821 atm.L/Kmol Number of mole (n) =?Using the ideal gas equation, we can obtain the mole of Xe as follow:
n = PV / RT
n = (0.98 × 0.035) / (0.0821 × 298)
n = 0.0014 mole
How to determine the mass of XeMole = 0.0014 moleMolar mass of Xe = 131 g/moleMass of Xe = ?Mass = mole × molar mass
Mass of Xe = 0.0014 × 131
Mass of Xe = 0.183 g
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When molten magma cools ________ under the surface, it forms _________ igneous rocks.
A. rapidly, extrusive
B. slowly, extrusive
C. rapidly, intrusive
D. slowly, intrusive
What was the weakness of the rutherford model of the atom that bohr addressed?
The weakness of the rutherford model of the atom that bohr addressed is that
The energy of the atom is quantized andThe atom does not lose energy as the electon rotates about the nucleusWhat is Rutherford model of the atom?The Rutherford model of the atom proposed by Ernest Rutherford in 1911 shows that the atom is much hollow space with its mass concentrated at the center being surrounded by electrons. It is the planetary model.
What is the Bohr model of the atom?The Bohr model of the atom proposed by Neils Bohr in 1913 suggests that
the energy of an atom is quantized and that it does not lose energy as the electron rotates about the nucleus.What was the weakness of the rutherford model of the atom that bohr addressed?The weakness of the rutherford model of the atom that bohr addressed is that
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