Which of the following statements is true for a scientific theory?
It is a tentative explanation.
It is tested by multiple scientists.
It is based on only one experiment.
It is investigated over a short period.
Answer:
It is tested by multiple scientist
Explanation:
just took the test, B is correct
What is the standard cell potential for a voltaic cell using the Pb2 /Pb and Mg2 /Mg half-reactions and which metal is the cathode
Answer:The standard cell potential, E˚cell =2.234 V, Pb metal is the cathode.
Explanation:
The Half cell reactions are
Pb2+(aq) + 2e– > Pb(s) ------E˚ = –0.136 V
Mg2+(aq) + 2e–>Mg(s)------- E˚ = –2.37 V
In a voltaic cell, reduction occurs at the cathode and oxidation occurs at the anode
Mg(s)---->Mg2+(aq) + 2e– ( anodic oxidation)
Pb2+(aq) + 2e----> Pb(s) ( Cathodic reduction)
We can see that Mg has a more negative reduction potential value leading to having a low reduction potential and therefore will occur at the anode since it will be oxidized. On the other hand Pb2+ has a less negative reduction potential and therefore will have a high reduction making it to occur at the cathode and be reduced
Using The standard cell potential, E˚cell = E˚cathode – E˚anode
E˚cell = –0.136 - (–2.37)
E˚cell=2.234 V
What makes a solution saturated?
Answer:
maximum amount of solute that is capable of being dissolved
Answer: A solution that contains a maximum amount if solute that is capable of being dissolved
Explanation:
A saturated solution is a solution that contains the maximum amount of solute that is capable of being dissolved.
A formula that relates the amount of a substance to a mass?
Explanation:
A formula mass of substance is a sum of the average atomics masses of each atom represented in the chemical formula and is expressed in atomic mass units.the formula mass of covalent compound is also called the molecular mass
How are alloys made?
What is the relationship between KMT and Sea Level Rise?
Relationship between KMT and Sea Level Rise because sea level rise in KMT with distance of 760nm
KMT is described as the behavior of gases and also it is used to explain macroscopic properties of a gas such a pressure and temperature and sea level rise is an increase in the level of the world oceans due to the effects of global warming and burning fossil fuels is one of the causes of global warming because it releases carbon dioxide and other heat-trapped gasses into the atmosphere so here the relationship between kinetic molecular theory and sea level rise is distance between sea level and KMT is 760nm sea level is rise because gas level is is increases.
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A 60.0 mL sample of nitrogen is warmed from 350 K to 400 K. Find its new volume if the pressure remains constant.
0.0145 ml
52.50 ml
0.0191 ml
68.57 ml
yes
Answer:68.57
Explanation:
What is the condensed structural formula of C7H8N4O2
Answer:
C7H8N4O. The molecular formula C7H8N4O2 (molar mass: 180.16 g/mol) may refer to: Paraxanthine. Theobromine.
The bond angles increase steadily in the series PF3, PCl3, PBr3, and PI3. Using the concepts that you have learned in chapters 7-10, explain this observation.
Answer:
See explanation
Explanation:
Electronegativity is the ability of an atom in a molecule to attract the shared electrons of a covalent bond towards itself. Electronegativity is a trend that increases across the period and decreases down the group in the periodic table.
All the compounds listed are halides of phosphorus. The electronegativity of halogens decrease in the order; F> Cl> Br > I. Hence F has the greatest electronegativity in the group. It decreases as atomic and ionic radius increases.
As the electronegativity of the halogen atom decreases, the electron pair on the halogen atom lie closer to the central phosphorus atom hence the repulsion between electrons increases and so does the bond angle increase likewise.
I need help with this question
Answer:
kajjajjanwjsjjsjsjsjsjjsjsj
Explanation:
jqqjjqj
The net ionic equation for the dissolution of zinc metal in aqueous hydrobromic acid is ________.
Answer:
[tex]Zn(s)+2H^+(aq)\rightarrow Zn^{2+}(aq)+H_2(g)[/tex]
Explanation:
Hello!
In this case, since writing the net ionic equation implies the complete molecular equation, we should start by:
[tex]Zn(s)+2HBr(aq)\rightarrow ZnBr_2(aq)+H_2(g)[/tex]
Next, we represent the ionization of the aqueous species:
[tex]Zn(s)+2H^+(aq)+2Br^-(aq)\rightarrow Zn^{2+}(aq)+2Br^-(aq)+H_2(g)[/tex]
Whereas the spectator ions, those at both reactants and products are cancelled out so the net ionic equation is obtained:
[tex]Zn(s)+2H^+(aq)\rightarrow Zn^{2+}(aq)+H_2(g)[/tex]
Best regards!
3) What will be the molecular mass of gas,11.2l of which at NTP weight 14 gm?
Answer:
30 g/mol
Explanation:
Step 1: Given data
Volume of the gas at NTP: 11.2 LMass of the gas: 14 gStep 2: Calculate the moles corresponding to 11.2 L of gas
At normal temperature and pressure (1 atm, 293.15 K), 1 mol of a gas has a volume of 24.05 L.
11.2 L × 1 mol/24.05 L = 0.466 mol
Step 3: Calculate the molecular mass of the gas
0.466 moles of the gas weigh 14 g. The molecular mass is:
M = 14 g/0.466 mol = 30 g/mol
Calculate the pHpH of a 0.10 MM solution of HClHCl . Express your answer numerically using two decimal places.
Answer: The pH 0f 0.10 solution of HCl is 1.00
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
[tex]HCl\rightarrow H^++Cl^{-}[/tex]
According to stoichiometry,
1 mole of [tex]HCl[/tex] gives 1 mole of [tex]H^+[/tex]
Thus [tex]0.10[/tex] moles of [tex]HCl[/tex] gives =[tex]\frac{1}{1}\times 0.10=0.10[/tex] moles of [tex]H^+[/tex]
Putting in the values:
[tex]pH=-\log[0.10][/tex]
[tex]pH=1.00[/tex]
Thus pH 0f 0.10 solution of HCl is 1.00
how do you do stoichiometry
suppose we have a reaction as follows :
nA + mB ---> pC + qD
where n,m,p,q are natural numbers
these natural numbers are called stoichiometric coefficients .
Eg:
2P + 3Br2 ---> 2PBr3
here, 2, 3 from reactant side and 2 from product side are called stoichiometric coefficients
hope this helps...
This feature of a volcano is called an____________________which releases heated ash and Tephra through its column generating its own lightning.
Fill in the blank!
Answer:
Volcanic Eruption releases heated ash and Tephra through its column generating its own lightning.
Hope it helps!<3
A minority of elements on the right side of the periodic table that tend to form the negative charges
Answer:
Wrong
Explanation:
Because they are non metals and tends to form negative charged ions
Every neutral atom of a given element has the same number of what two subatomic particles?
A. Protons and neutrons
B. Protons and electrons
Answer:
protons and electrons
Explanation:
because two atoms of the same elements have different(mass)isotope so the answer is B
Drag the text elements below into the gray boxes to create an equation that calculates the mass of CH, required to create 24.0 g of H₂O.
The mass of CH₄ required to create 24.0 g of H₂O is 10.67 g
Balanced equationCH₄ + 2O₂ -> CO₂ + 2H₂O
The following were obtained from the balanced equation:
Molar mass of CH₄ = 12 + (1 × 4) = 16 g/mol Mass of CH₄ from the balanced equation = 1 × 16 = 16 gMolar mass of H₂O = (2 × 1) + 16 = 18 g/mol Mass of H₂O from the balanced equation = 2 × 18 = 36 gFrom the balanced equation above,
36 g of H₂O were produced from 16 g of CH₄
How to determine the mass of CH₄ requiredFrom the balanced equation above,
36 g of H₂O were produced from 16 g of CH₄
Therefore,
24 g of H₂O will be produced from = (24 × 16) / 36 = 10.67 g of CH₄
Thus, 10.67 g of CH₄ is needed for the reaction
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Complete question:
See attached photo
HelapPPPpPPPPpThe three states of matter that may change during a physical change are O atoms, molecules, electrons O color, shape, size O solid, liquid, gas
Answer:
Solid liquid and gas
Explanation:
what is meant by votalite in chemistry
Answer: This may help you
https://ay.live/BNNBhX
Explanation:
Which form of asexual reproduction describes the process of a cell dividing to
produce a copy?
A. Binary fission
B. Budding
C. Fragmentation. PLS I NEED HELP
D. Amputation
PLS I NEED HELP
Answer:A
Explanation:Binary Fission, meaning ‘getting divided into half’ is a type of asexual reproduction where a single living cell grows twice its size and then splits to form two identical daughter cells, each carrying a copy of the parent cell’s genetic material. Examples of cells that use binary fission for division
Answer:
i think its a
Explanation:
There’s bots who create questions and then suddenly get a response and there’s me who waits hours for a response. Lol really nice
If anyone can answer this I will make you brainiest.
The____ of a gas solute determines whether or not that gas will dissolve in a solvent.
Given that 2Al(s) + 3 2 O2(g) → Al2O3(s)
ΔH o rxn = −1601 kJ/mol and
2Fe(s) + 3 2 O2(g) → Fe2O3(s)
ΔH o rxn = −821 kJ/mol
calculate the standard enthalpy change for the following reaction:
2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s)
Answer:
ΔH°rxn = -780kJ
Explanation:
It is possible to find enthalpy change of a reaction by the sum of analogue reactions (Hess's law).
Using the reactions:
1. 2Al(s) + 3/2O2(g) → Al2O3(s) ΔH°rxn = −1601 kJ/mol
2. 2Fe(s) + 3/2O2(g) → Fe2O3(s) ΔH°rxn = −821 kJ/mol
1 - 2:
2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s)
ΔH°rxn = ΔH°rxn(1) - ΔH°rxn(2)
ΔH°rxn = −1601 kJ/mol - (-821 kJ/mol)
ΔH°rxn = -780kJ
Considering the Hess's Law, the enthalpy change for the reaction is -780 kJ.
Hess's Law indicates that the enthalpy change in a chemical reaction will be the same whether it occurs in a single stage or in several stages. That is, the sum of the ∆H of each stage of the reaction will give us a value equal to the ∆H of the reaction when it occurs in a single stage.
In this case you want to calculate the enthalpy change of:
2 Al(s) + Fe₂O₃(s) → 2 Fe(s) + Al₂O₃(s)
which occurs in two stages.
You know the following reactions, with their corresponding enthalpies:
Equation 1: 2 Al(s) + [tex]\frac{3}{2}[/tex] O₂(g) → Al₂O₃(s) ΔH = −1601 kJ/mol
Equation 2: 2 Fe(s) + [tex]\frac{3}{2}[/tex] O₂(g) → Fe₂O₃(s) ΔH = −821 kJ/mol
Because of the way formation reactions are defined, any chemical reaction can be written as a combination of formation reactions, some going forward and some going back.
Firs stepTo obtain the enthalpy of the desired chemical reaction you need 2 moles of Al(s) on reactant side and it is present in first equation so let's write this as such.
Secod stepNow, 1 mole of Fe₂O₃(s) must be a reactant and is present in the second equation. Since this equation has 1 mole of Fe₂O₃(s) on the product side, it is necessary to locate the Fe₂O₃(s) on the reactant side (invert it). When an equation is inverted, the sign of ΔH also changes.
In summaryYou know that two equations with their corresponding enthalpies are:
Equation 1: 2 Al(s) + [tex]\frac{3}{2}[/tex] O₂(g) → Al₂O₃(s) ΔH = −1601 kJ/mol
Equation 2: Fe₂O₃(s) → 2 Fe(s) + [tex]\frac{3}{2}[/tex] O₂(g) ΔH = 821 kJ/mol
Adding or canceling the reactants and products as appropriate, and adding the enthalpies algebraically, you obtain:
2 Al(s) + Fe₂O₃(s) → 2 Fe(s) + Al₂O₃(s) ΔH= -780 kJ
Finally, the enthalpy change for the reaction is -780 kJ.
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How many grams are there in 4.4 moles of calcium, Ca?
Answer:
180 g Ca
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
4.4 mol Ca
Step 2: Identify Conversions
Molar Mass of Ca - 40.08 g/mol
Step 3: Convert
[tex]4.4 \ mol \ Ca(\frac{40.08 \ g \ Ca}{1 \ mol \ Ca} )[/tex] = 176.352 g Ca
Step 4: Check
We are given 2 sig figs. Follow sig fig rules and round.
176.352 g Ca ≈ 180 g Ca
When 35.0 mL of 0.400 M hydrochloric acid and 35.0 mL of 0.400 M sodium hypochlorite are combined, the pH of the resulting solution will be :
Answer:
pH = 7.49
Explanation:
This is a buffer solution. We can apply Henderson Hasselbach equation:
pH = pKa + log ((total mmoles - mmoles HCl) / mmoles HCl)
We have the same amount of mmoles.
35 mL . 0.400 M = 14 mmoles HCl
35 mL . 0.400 M = 14 mmoles NaClO
Total moles are 28 mmoles.
We replace data:
pH = pKa + log ((28 mmoles -14 mmoles) / 14 mmoles)
Notice that the relation in log = 1. So pH = pKa
pKa for HClO is 7.49
When pH = pKa we have the same amount of base and acid. Notice, that we have the same mmoles of HCl and NaClO.
Remember that a buffer can be prepared with:
a) A weak acid and its conjugate base (acetic /acetate)
A weak base and its conjugate acid (ammonia/ammonium)
b) A weak acid with a strong base, where the acid can be in excess.
c) A conjugate base (salt from weak acid) with a strong acid, where the base can be in excess. (This case but, the base is not in excess, that's why ph = pKa)
Why is Hydrogen-2 a heavier isotope than Hydrogen-1?
A. Hydrogen-2 has one more proton
B. Hydrogen-2 has one more neutron
Answer:
It is A. hydrogen -2 has one more proton
Calculate the mass percent of hydrogen in CH3OCH3. Answer in 2 decimal places without unit.
The answer will be 13.02 % of hydrogen.
Mass Percentage : It is used to estimate the mass % of an element in a compound.
CH3OCH3 - chemical name is dimethyl ether also known by the name of methoxymethane.
It is an organic compound.
Also is an isomer of an ethanol.
There are 6 molecules of Hydrogen present in CH3OCH3
So, mass percent of hydrogen = Total number of molecules present in the compound *100 / Molecular weight of the compound
= 6 *100 / Molar mass of CH3OCH3
= 600 / 46.07 = 13.02 %
So, the mass percentage of hydrogen in C2H6O will be 13.02 %
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A gas mixture contains 0.800 mol of N2, 0.200 mol of H2, and 0.150 mol of CH4. What is the mole fraction of H2 in the mixture?
Answer:
0.1739
Explanation:
0.800 mol of N2
0.200 mol of H2
0.150 mol of CH4
Total moles of the mixture = 0.8 + 0.2 + 0.150 = 1.150 mol
Mole fraction of H2 = Number of moles of H2 / Total moles
Mole Fraction = 0.2 / 1.150 = 0.1739
Which of Earth’s spheres do humans impact and how?
You will get a free foot if you answer this
Answer:
humans have a huge impact on all spheres. if you negatively impact the spheres, such as burning fossil fuels, it'll pollute the atmosphere.
Explanation:
All four spheres of Earth are susceptible to human influence. Burning fossil fuels can cause pollution to be released into the atmosphere. Garbage accumulated by humans in landfills has an impact on the geosphere. Human waste enters waterways and has an effect on the hydrosphere.
What is geosphere ?Different definitions of the geosphere have conflicting uses. It can be used to refer to the atmosphere, lithosphere, hydrosphere, and cryosphere as a whole. Different mass and/or energy flows can be exchanged between the various geosphere collectives.
Land erosion and soil movement currently result from human activity more frequently than from any natural mechanism. Human-caused air and water pollution has a negative impact on the environment, rivers, and lakes, harming both other animals and people's health.
According to some scientists, humans have their own sphere, the "anthrosphere." But for the purposes of this module, people will also be considered a component of the biosphere.
Thus, Garbage accumulated by humans in landfills has an impact on the geosphere.
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Which of the following is the highest level in the organization of living things?
Organ system
Organism
Tissue
Compound
Answer: The correct answer is Organism.
Explanation:
because.....
that is the part that control the rest.
*Hopefully this helps!!!
Answer:
organism or organ system
Explanation:
i forgot what that dude said up there