The half-life of carbon-11 is 20.3 minutes. 6.01 mg of a 100.0 mg sample remains after 1.50 hours
First, we need to determine how many half-lives have passed in 1.50 hours. Since the half-life of carbon-11 is 20.3 minutes, there are 4.41 half-lives in 1.50 hours (90 minutes / 20.3 minutes per half-life).
To calculate the remaining amount of the sample, we use the formula:
amount remaining = original amount x (1/2)^(number of half-lives)
Plugging in the values we have:
amount remaining = 100.0 mg x (1/2)⁴
amount remaining = 100.0 mg x 0.0601
amount remaining = 6.01 mg
The ratio that makes up the percentage can be written as a fraction of 100.
Therefore, after 1.50 hours, only 6.01 mg of the original 100.0 mg sample of carbon-11 remains.
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Which of the following contains the most hydrogen atoms?
Group of answer choices
15.00 g of ammonia
1.00 mol of ammonia
1.00 mol of water
10.0 g of water
1.00 mol of water contains the most hydrogen atoms.
1 mol of water(H2O) contains 2 mol of hydrogen atoms
molar mass of hydrogen = 1.01 g/mol,
so 1 mol of water contains 21.01 = 2.02 g of hydrogen.
1 mol of Ammonia (NH3) contains 1 mol of hydrogen atoms
molar mass of hydrogen = 1.01 g/mol,
so 1 mol of ammonia contains 11.01 = 1.01 g of hydrogen.
hydrogen in 10.0 g of water = 4.83 ×[tex]10^(22)[/tex] hydrogen atoms
hydrogen in 15.00 g of ammonia = 1.48 ×[tex]10^(23)[/tex] hydrogen atoms.
1 mol of water contains the most hydrogen atoms. This is because water, chemically represented as H2O, contains two hydrogen atoms for every oxygen atom. While 1 mol of ammonia(NH3) contains 1 mol of hydrogen atoms, 1 mol of water contains 2 mol of hydrogen atoms.
Therefore, 1 mol of water contains more hydrogen atoms than 1 mol of ammonia, and that's why option 3 -1 mol of water contains the most hydrogen atoms out of the options provided.
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When rutherford did the gold foil experiment where most of the particles went through the foil and a few were deflected, how did the model of the atom change?
Only a small percentage of the particles have been seen to be deflected, while the majority have passed through the layer. Rutherford concluded as a result that an atom's mass was concentrated at its centre.
What happened to most of the particles that Rutherford shot at the sheet of gold foil?With his gold-foil experiment, physicist Ernest Rutherford developed the nuclear theory of the atom. When he shot a stream of alpha particles at a sheet of gold foil, a few of the particles were deflected. He determined that the deflections were being caused by a small, compact nucleus.Because the majority of the atom's space is unoccupied, the majority of alpha particles flowed through the gold foil without being deflected.The positive-charged alpha particles struck a piece of gold foil. Most alpha particles passed through unharmed. This demonstrated that the gold atoms primarily consisted of empty space.The majority of an atom is empty space, with a small, dense, positively-charged nucleus, as demonstrated by Rutherford's gold foil experiment. Rutherford suggested the nuclear model in response to these findings.To learn more about Rutherford refer to:
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Please help Chemistry
5.0 mol Al reacts with 6.0 mol O2 to
form Al2O3.
4AI + 302 → 2Al2O3
How many moles of Al2O3 form
when all 5.0 moles of Al are used up?
[ ? ] mol Al2O3
Round your answer to the tenths place.
The amount of the aluminum oxide that is formed is 2.5 moles.
What is the number of moles formed?We must have it at the back of our minds that in the case of the questions that involves stoichiometry, the limiting reactant can be said to be the compound that is used up in the reaction.
We are told here that the substance that has been used up in this reaction is the aluminum then it means that this must be the limiting reactant here.
If 4 moles of aluminum produces 2 moles of aluminum oxide
5 moles of aluminum would produce 5 * 2/4
= 2.5 moles of aluminum oxide.
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How does a sea breeze affect the weather?
A.
It decreases land temperatures near the ocean.
B.
It increases land temperatures near the ocean.
C.
It decreases rain formation over land near the ocean.
D.
It increases the cloud coverage over the land near the ocean.
Pls help!!
Answer:
it decreases land temperature near the ocean
Calculate the ratio of H* ions to OH-ions at a pH = 7.
Find the concentration of H* ions to OH ions listed in
Table B of your Student Guide. Then divide the H*
concentration by the OH concentration. Record this
calculated ratio in Table A of your Student Guide.
Compare your approximated and calculated ratios of H+
ons to OH-ions at a pH = 7. Are they the same? Why or
why not? Record your comparison in Table A.
What is the concentration of H+ ions at a pH = 7?
mol/L
What is the concentration of OH-ions at a pH = 7?
mol/L
What is the ratio of H+ ions to OH-ions at a pH = 7?
:
Please help!! Worth 100 points!!
a) The concentration of the hydrogen ions is 1 * 10^-7 M
b) The concentration of the hydroxide ions is 1 * 10^-7 M
c) Ratio of the hydrogen to the hydroxide ion is 1:1
What is the pH?We know that the pH of the solution would have to do with ratio of the hydrogen ion and the hydroxide ions that we have in the solution. We know that the pH values that range from 0 -6 is acid, 7 is neutral and 8 - 14 is basic.
Then we have that;
Concentration of the hydrogen ion in the solution is obtain from the formula;
[H^+] = Antilog (-pH)
At pH 7 we have;
[H^+] = Antilog (-7)
= 1 * 10^-7 M
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If a reaction appears to result in a change of mass, it is usually because a reactant or product that is a __________ has not been taken into account. What word completes the sentence?
Answer:Gas is the answer
An artist made a bowl using ceramic material. Ceramic materials have strong bonds between the atoms.
How do the chemical bonds within ceramics make it a good material for making bowls?
Answer options with 4 options
A.
It is a good conductor of heat.
B.
It is hard and has a high melting point.
C.
It has electrons that are able to move freely between atoms.
D.
It has long chains of molecules that are tangled at room temperature.
It has long chains of molecules that are tangled at room temperature that make it a good material for making bowls.
What is molecule?The smallest particle of a material that possesses all of its physical and chemical characteristics. One or more atoms make form a molecule. A molecule is the smallest particle of any material that may exist independently while retaining the physical and chemical characteristics of the substance and is composed of one or more components. Molecules are further subdivided into atoms. For example, an oxygen atom is denoted as O, whereas an oxygen molecule is denoted as O2. Molecules are classified into three types: atom molecules, element molecules, and compound molecules.
Here,
It features lengthy chains of molecules that are tangled at room temperature, making it an excellent material for bowls.
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Explain the trend for the last successive ionization energies for 2nd period of elements (Li, Be, B, C, N, O, F, Ne).
In general, ionization energy increases across a period and decreases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant.
Define ionization energies?The ionization energy is a metric indicating an element's capacity to engage in chemical processes that call for the donation of electrons or the production of ions. It is also often correlated with the type of chemical bonding that occurs when elements combine to form compounds. Additionally see electron affinity and binding energy.The least amount of energy needed to free the most loosely bound electron from an isolated gaseous atom, positive ion, or molecule is known as the ionization energy in physics and chemistry.The amount of energy required for an isolated, gaseous atom to discharge an electron, creating a cation, is known as the ionization energy.To learn more about ionization energies refer to:
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Al will replace the metal in the ionic compound Fe₂O3: True or False
The ionic compound's metal will be replaced with AI. True for Fe2O3
What is ionic and covalent bond?Atomic bonds can be covalent or ionic in nature. The structures and characteristics of these bonds vary. Pairs of electrons are included in covalent bonds through the binding of two atoms in a specific orientation. Ionic bonds, on the other hand, are bonds that connect two ions.
How can an ionic compound be recognised?Ionic bonding will typically be present in compounds where a metal is bound to either a quasi or a semi-metal. Molecular compounds are those that contain only non-metals or quasi combined with non-metals and exhibit covalent bonding.
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C4H8 +O₂ → _____ CO₂ + ______ H₂O
Answer:
look at the attachment I wrote it out for you.
QUESTION 1.
Element X on Planet Qatar has three known isotopes: X-121 with a relative abundance of 43.2%, X-123 with a relative abundance of 53.1%, and X-129 with a relative abundance of 3.70%. What is the average atomic mass in amu of Element X given this information?
QUESTION 2.
How did Rutherford's experiment change the way scientists had previously viewed atomic structure? How did this pave the way for subsequent changes up to and including the currently accepted quantum mechanical atomic model?
QUESTION 3.
How is percent abundance related to average atomic mass?
a) The percentage abundance determines the relative atomic mass.
b) The relative atomic mass for the element X is122.5 amu
c) The Rutherford's model explained showed the movement of the electrons.
What is the relative abundance?The isotopes are the kinds of atoms of an element that we can see. We know that all the element that we have in the periodic table are composed of the isotopes and the isotopes of the elements are important in the determination of the relative atomic mass of the element that we may be considering here called X
We can now be able to see from the forgoing that we have here that;
Relative atomic mass = Weighted average of all the isotopes
As such we have;
(121 * 0.432) + (123 * 0.531) + (129 * 0.0370)
52.27 + 65.31 + 4.773
=122.35 amu
The Rutherford model of the atom can also be called the planetary model of the atom and this is the model that can be able to explain to us the way that the electrons move round the nucleus.
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How can you compare the rates of effusion of two gases in a mixture?
You can compare the rates of effusion of two gases in a mixture by their molecular weights.
The square root of a gas's molecular weight has an inverse relationship with the rate of effusion of that gas. Therefore, you may compute the square roots of two gases' molecular weights and then invert that ratio to compare the rates of effusion of the two gases in a mixture.
The rate of effusion will be slower for the gas with the greater molecular weight and faster for the gas with the lower molecular weight.
For instance, the ratio of two gases' rates of effusion is given by R = (M1 / M2)-1 if their molecular weights are M1 and M2, respectively.
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How is Hess's law applied in calculating enthalpy?
A. The first and last reactions in a path are added together.
B. Similar equations are substituted for unknown reactions.
OC. All the reactions in a path are added together.
D. The final equation in a path from reactants to products is used.
SUBMIT
according to the question, All the reactions in a path are added together.
What is the reactions?
Reactions are the processes in which one or more substances are changed into one or more new substances. They are caused by a chemical change in which the atoms of the reactants rearrange to form the atoms of the products. Reactions can be classified according to the type of energy released or absorbed during the reaction, such as exothermic and endothermic. Reactions can also be classified according to the type of reactants involved, such as single-replacement and double-replacement reactions. Reactions can occur quickly and release a large amount of energy, or they can occur slowly and release little or no energy. Reactions can also occur in a series of steps, such as in a reaction mechanism. In general, reactions require reactants, a catalyst, and an energy source in order to occur.
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the elements and compounds present after a chemical reaction are called the ___________.
The elements and compounds present after a chemical reaction are called the products.
How many moles of hcl are in a 100 cm3 of 0. 2 mol/dm3 hydrochloric acid solution?.
It contain 2 mol of HCl. To find the moles of HCl, you have to change the volume units into dm³ or liter.
How to calculate the value of that HCl mole?
As per data given:
Vacid = 100 cm³
Molacid = 0.2 mol/dm³ = 0.2 mol/L
First, we have to change volume unit into liter or dm³. So
Vacid = 100 cm³ = 0.1 L
Then calculate the moles of HCl:
Moles of HCl = Molacid : Vacid
Moles of HCl = 0.2 : 0.1
Moles of HCl = 0.2 x 10
Moles of HCl = 2 mol
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Correctly classify each of the following compounds as highly soluble or as either slightly soluble or insoluble in water.
ionic and polar compounds are highly soluble in water whereas the covalent and organic compounds are highly insoluble in water
What is the difference between soluble and insoluble?Soluble fiber dissolves in water, and includes plant pectin and gums. Insoluble fiber doesn't dissolve in water. It includes plant cellulose and hemicellulose. Most plants contain both soluble and insoluble fiber, but in different amounts.Soluble fiber is found in foods such as oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. Insoluble fiber appears to speed the passage of foods through the stomach and intestines and adds bulk to the stool. It is found in foods such as wheat bran, vegetables and whole grains.Soluble means capable of dissolving in a solvent whereas insoluble means incapable of dissolving in a solvent.To learn more about soluble and insoluble refers to:
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Do you think odor is a property? Explain your ideas.
Answer:
yes, odor is classified as a physical property
Explanation:
A gaeou mixture of C2H4, CH4, CO and N2 at 400 K & 1 atm wa added with exce of O2 & ubjected to parking in a rigid container (volume contant). Preure of CO2 obtained at 400 K in ame volume i 0. 9 atm and that of H2O vapour i 0. 8 atm. If mole of C2H4 and CH4 are equal, then find the um of preure of C2H4 and N2 ga
The pressure of C2H4 and N2 gas is 0.3 atm
Based on the information provided, it appears that C2H4 and CH4 are added to a mixture of CO and N2 and then exposed to excess oxygen. The resulting mixture is then placed in a rigid container at a constant volume, and the pressure of CO2 and H2O vapor is measured to be 0.9 atm and 0.8 atm, respectively.
If the number of moles of C2H4 and CH4 is equal, the sum of the pressure of C2H4 and N2 gas can be calculated by subtracting the pressure of CO2 and H2O vapor from the total pressure. Since the total pressure is 1 atm, the sum of the pressure of C2H4 and N2 gas is:
1 atm - 0.9 atm - 0.8 atm = 0.3 atm
It is worth noting that this answer is based on the information provided and any additional information or assumptions may affect the final result.
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If you were to heat up a 1-kilogram rock and 1 kilogram of water you would see that the rock both gains heat and loses heat faster than the water. If you allow them to cool down which one will come back to room temperature faster?
You would observe that the rock absorbs heat more quickly than the water and releases it more slowly. The rock will reach room temperature more quickly if you let them cool.
How come land loses heat more quickly than water?The majority of solar radiation that hits water's surface is reflected back into the atmosphere. Given that land absorbs more solar radiation, both the land's surface and the vegetation it supports retain more heat.
Soil or water will release heat more slowly.Water absorbs and releases heat more slowly than land because its specific heat is higher than that of dry soil. Due to the high heat capacity of water, large bodies of water often tend to moderate the temperature of neighboring land.
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Draw the structure of the cycloalkane 1, 4-dimethylcyclohexane. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default. Include all hydrogen atoms
The parent component in the structure of 1,4- dimethyl cyclohexane is cyclohexane, which has two methyl groups attached at the first and fourth positions of the carbon ring.
Cyclohexane is a saturated hydrocarbon with the molecular formula CₙH₂ₙ where n represents the number of carbon atoms present in the organic compound. They are represented as simple polygons with the sides representing carbon-carbon bonds. Each carbon atom is held together by two hydrogen atoms. A molecule's multiple rings may share one or more common atoms. One carbon atom is shared by two rings in spirocyclic compounds. These compounds are uncommon.
According to the IUPAC system, cycloalkanes are named with the prefix cyclo-.
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Using the diagram above, match the description to the corresponding location in the carbon cycle model. Provide the letter only.
Carbon dioxide is converted to sugar used for food.
Carbon trapped in fossil fuels is converted to carbon dioxide.
Organic carbon is converted to fossil fuels.
Carbon dioxide is converted to carbonates.
Sugar is broken down and converted to carbon dioxide.
Location ________
Location ________
Location ________
Location ________
Location ________
,,,, ....... ... .. .. . . . .
Laura has three beakers. Each contains 200 cm³ of a colourless liquid. Describe how Laura could find out which beakers contain pure water, and which contain solutions. Explain your answer.
Laura could use a few different methods to determine which beakers contain pure water and which contain solutions. One method is to test the boiling point of each liquid. Pure water boils at 100 degrees Celsius at standard pressure. If the liquid in a beaker boils at a temperature higher than 100 degrees Celsius, it is likely a solution and not pure water. Another method is to test the freezing point of each liquid. Pure water freezes at 0 degrees Celsius at standard pressure. If the liquid in a beaker freezes at a temperature other than 0 degrees Celsius, it is likely a solution and not pure water.
Another method is through density test. Pure water has a density of 1g/cm³ at 4°C. Laura can use a hydrometer, which is an instrument that measures the density of a liquid to check if the density of the liquids in the beakers is equal to 1g/cm³. If it is not, then it is not pure water.
Additionally, Laura could also test the conductivity of the liquids. Pure water is a poor conductor of electricity, whereas solutions can conduct electricity. Laura could use a conductivity meter to check the conductivity of the liquids. If a liquid conducts electricity, then it is likely a solution and not pure water.
Finally, Laura could also use a refractometer, which measures the refractive index of the liquid. The refractive index of pure water is 1.333 and any deviation from this value indicates the presence of dissolved solutes.
It's important to notice that no single test can confirm that a liquid is pure water, but a combination of tests can give us a strong indication of it.
Under what conditions will a gas be most likely to exhibit the ideal gas properties predicted by the ideal gas law?
The ideal gas law describes the behavior of a gas under ideal conditions, which typically means that it is at a low density and a high temperature.
When these conditions are met, the gas will behave in a manner that is consistent with the ideal gas equation. Generally, a gas will exhibit its ideal properties when it is in a container with a large volume, has a low pressure, and is at a high temperature.
Additionally, the gas particles must be small and non-interacting, meaning that they do not interact with each other. When these factors are taken into account, a gas will most likely display the ideal gas properties predicted by the ideal gas law.
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0. 399 g of an unknown gas at stp fills a 550. Ml flask. What is the molar mass of the gas?.
The molar mass of the gas would be 16.36 g/mole.
The formula for molar mass: M = (m.RT)/ (P.V)
P stands for the pressure of the ideal gas
V stands for the volume of the ideal gas
R stands for the universal gas constant
T stands for the temperature.
In this case, we are given that:
P = 1 atm (standard conditions)
T = 273K (standard conditions)
R = 0.082 lit. atm. K⁻¹.mol⁻¹
Mass of gas (m) = 0.399 g
Volume of gas (V) = 550 mL = 0.55 L
Therefore, the molar mass of the gas would be:
M = (m.RT)/ (P.V)
M = (0.399 x 0.08206 x 273) / (1 x 0.55)
M = 16.36 g/mole
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When scientists analyze the rock record, they look for fossils evidence. how are scientist able to determine that the majority of all organisms are now exitinct?
An organism is considered extinct if the fossil evidence reveals the remains of one that is no longer present-day. As a result, scientists might conclude that the majority of Earth's animals are already extinct because they have noted that certain qualities and traits are absent from species that are still alive.
What is extinction?The phrase "extinction" refers to the end of a particular type of organism or a set of types, typically a species. Although the ability to reproduce and bounce back may have been lost earlier, the death of the last individual of the species is widely considered to be the moment of extinction.
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How might the atoms {metals differ from on another?
Atoms of different metals can differ in number of protons, electron configuration, atomic radius, melting/boiling point, hardness/ductility, and conductivity.
what is difference between atom metals with one another?
Atoms of different metals can differ from each other in a number of ways, including:
Number of protons: The number of protons in the nucleus of an atom determines its atomic number and thus its identity as an element. Different metals will have different atomic numbers and therefore different numbers of protons.Electron configuration: The arrangement of electrons in the outermost shell of an atom, also known as the valence electrons, determine the chemical properties of an element. The electron configuration of different metals will be different.Atomic radius: The size of an atom is determined by its atomic radius. Different metals will have different atomic radii.Melting and boiling point: The melting and boiling points of different metals will vary depending on the strength of the metallic bond holding the atoms together. Generally, metals with stronger metallic bonds will have higher melting and boiling points.Hardness and ductility: The hardness and ductility of a metal depend on the crystal structure and the strength of metallic bonds. Harder metals are less ductile and more brittle, while softer metals are more ductile and less brittle.Conductivity: The ability of a metal to conduct electricity is related to the number of free electrons in the outermost shell of its atoms, the metallic bond strength, and the atomic radius. Different metals will have different conductivity.To learn more about atom refer:
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is it true that Kelp and plants can break down starch into sugar and use it to grow and release in the process only when it is dark?
Answer:
Yes it's true ooooooooo
How many grams of BE(NO2)2 are needed to make 550 mi of a 2.5 m solution?
The mass of Be(NO₂)₂ required to make 550 mL of a 2.5 M solution is 126.25 g.
What is the molar concentration of a solution?Molar concentration is a measurement of the concentration of a solute in a solution, in terms of the quantity of material per unit volume of solution. The number of moles per liter, represented by the unit sign mol/L or mol/dm³ in SI units, is the most common way to measure molarity in chemistry.
Mathematically;
Molar concentration = number of moles/volume in liters
The number of moles is also determined using the formula below:
Number of moles = mass/molar mass
Hence;
Molar concentration = mass / molar mass * volume in liters
Therefore:
mass = Molar concentration * molar mass * volume in liters
The molar mass of Be(NO₂)₂ = 101 g/mol
Mass of Be(NO₂)₂ required = 2.5 * 500 * 1/1000 * 101
Mass of Be(NO₂)₂ required = 126.25 g
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Write the chemical equation that the diagram
represents.
In the given diagram, the first atom contains one valence electron and the second have 7 valence electrons. The first atom donates the one electron to the second atom and both achieve octet and forms and ionic compound.
What are ionic compounds?Ionic compounds are formed between a metal and non-metal. Metals are rich in electrons and easily loss one or more electrons to other atoms. Non-metals are electron deficient and can gain electron from metals. These electron loss and gain between atoms forms the ionic bond between them.
In the diagram the first atom contains total 11 electron of which one is valence electron. By donating this extra electron the atom can achieve octet. The second one contains total 17 electrons of which 7 are valence electrons, thus need one more electron to attain octet.
The first atom represents sodium atom and the second one is chlorine atom. Sodium donates its valence electron to Cl and form the ionic compound NaCl.
Na⁺ + Cl⁻ ⇒ NaCl
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What is the limiting reactant if 70. 0 g of c7h6o3 and 80. 0 g of c4h6o3 react?watersalicylic acidacetic anhydrideacetylsalicylic acid.
The limiting reactant if 70.0 g of C7H6O3 and 80.0 g of C4H6O3 react is salicylic acid (C7H6O3).
In this case, given that:
70g C7H6O3
80g C4H6O3
Molar mass of C7H6O3 = 138 g/mol
Molar mass of C4H6O3 = 102 g/mol
So, we need to convert C7H6O3 to C4H6O3 as below:
= 70g C7H6O3
= (molar mass of C4H6O3 / molar mass of C7H6O3) * mass of C7H6O3
= (102 / 138) * 70
= 51.74g C4H6O3
Thus, when 70.0 g of C7H6O3 and 80.0 g of C4H6O3 react, it will be:
80g C4H6O3 – 51.74g C4H6O3 = 28.26g C4H6O3
And, that means there are 28.26g C4H6O3 left after reacting it with C7H6O3.
Hence, the limiting reactant is salicylic acid (C7H6O3).
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