what pressure would it take to compress 250. l of helium gas initially at 1.00 atm into a 2.00 l tank at constant temperature?express your answer with the appropriate units.

960 molecules of magnesium oxide will form when excess magnesium reacts with 480 molecules of oxygen.

Wilhelm Ostwald, a German scientist, is widely credited with coining the term. Ultimately, though, the word mole derives from the Latin word moles, which meaning "a mass." The word molecule is connected to the word mole; it is a diminutive that means "a little bulk."

The quantity of matter in a system that equals the number of atoms in 0.012 kilograms of carbon-12; it is denoted by the symbol "mol".

Given that,

480 molecules of oxygen is there.

The equation becomes:

2Mg + O₂ → 2MgO

2 mol  1 mol   2 mol

Now,

1 molecule of oxygen give 2 molecule of MgO

480 molecule of oxygen will give (480 × 2) = 960 molecules of MgO

So, 960 molecules of magnesium oxide will form when excess magnesium reacts with 480 molecules of oxygen.

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The mole fraction of ethanol is 0.165

What do you mean by mole fraction ?

There are several ways to indicate the concentration of the solution and mole fraction is one of them. Mole fraction is a unit of concentration. In the solution, the relative amount of solute and solvents are measured by the mole fraction and it is represented by “X.”

The mole fraction is the number of moles of a specific component in the solution divided by the total number of moles in the given solution.

Molecular Mass of Ethanol = 46g

11.0 molal = 11 moles in 1 L solution

Molecular mass of water = 18g

Density of water= 1kg/m3 = 1000g/l

So, Mass of water in 1l solution = 1000g

so moles = 1000/18 = 55.55 moles

Thus, mole fraction of ethanol = 11.0/ ( 11.0 + 55.6 ) = 0.165

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The energy can travel through empty space without being carried in or by any matter is light.

What is light?

light is an electromagnetic wave and it can travel through a vacuum such as the empty parts of outer space. electromagnetic wave means it has both the proprties of electric field and magnetic field. In a model, a changing electric field creates a changing magnetic field. This changing magnetic field then creates a changing electric field and light.

What is the travelling speed of light?

In empty space, light travels at a speed of about 300,000 km/s. It does not require any substance or material to transport its energy. This means that light can pass across a vacuum—a place devoid of any air.

The energy can travel through empty space without being carried in or by any matter is light.

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The properties of the compounds are given as following:

Covalent compound

The atoms of covalent compounds are bonded between each other by covalent bonds. Covalent compounds make bonds by sharing one or more pairs of valence electrons.

Ionic compound

The atoms of ionic compound contains ions or charged particles. ionic compounds make bonds when an atom or more atoms lose or gain electrons.

Thus, the properties of compounds are:

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Predict the mass of hydrogen fuel produced when 2. seventy-three g of aluminum reacts in a single replacement reaction with extra sulphuric acid.

The yank Chemical Society ACS officially followed aluminum in 1925, however in 1990 The International Union of Pure and implemented Chemistry IUPAC regularly occurring aluminum as a worldwide fashionable. And so we land today: with aluminum used by the English speakers of North us, and aluminum used anywhere else.

The most comforting part of this tale is that both Aluminum and Aluminium are conventional and correct. Aluminum is preferred in North the us, while Aluminium is the spelling favored within the united kingdom and most different English-talking countries.

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The heat of vaporization or the vapor strain at any temperature.

Thermodynamics is a branch of physics that offers heat, paintings, and temperature, and their relation to electricity, entropy, and the bodily homes of being counted and radiation.

Thermodynamics is the study of the family members between warmth, paintings, temperature, and energy. The legal guidelines of thermodynamics describe how the power in a gadget changes and whether or not the gadget can carry out useful work in its environment.

Fourth law of thermodynamics the dissipative element of evolution is in a course of steepest entropy ascent. The zeroth regulation of thermodynamics was acknowledged earlier than regulation I of thermodynamics. motive.

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The Lewis structure for polyatomic carbonate anion would be two oxygen atoms bonded with carbon atom with a single bond and one double bond is present.

There are three σ bonds and π bond around carbon atom in the Lewis structure of CO3^2- ion. According to the question caron has 4 valanced electrons. There are three oxygen atoms in CO32- ion,

Therefore,

Total valence electrons given by oxygen atoms = 6 *3 = 18

There are -2 charge on CO32- ion. Therefore, there are two more electrons which contribute to the valence electrons.

Total valence electrons = 4 + 18 + 2 = 24

    Carbon has the more chance to be the center atom because carbon can show valance of 4. Oxygen's highest valence is 2. So, now we can build a sketch of CO3^2- ion.

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Iodine-123, which has a 13.3-hour half-life and a 25 mg initial concentration, will have 3.09 mg after 39.9 hours.

Using a first-order kinetics equation,

log C = logC0-Kt/2.302

An arrangement of chemical reactions where the rate of the reaction is proportional to the amount of the reactant and is dependent on the concentration of just one reactant.

The half-life of idodine- 123 is 13.3 hours.

from the formula of half-life K can be calculated.

The period of time it takes for a sample's ingredient to decrease by half in your body is known as the half-life.

T1/2 = 0.693/ K

13.3 hours= 0.693/K

K= 0.052 [tex]hour^{-}[/tex]

Substituting the value of K, C0, and t in the equation of first-order kinetics

logC= log(25) - 0.052 × 39.9/ 2.303

logC = 1.39-0.90

logC= 0.49

C= antilog (0.49)

C= 3.09 mg

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The true statement about zinc is b. Excess zinc can decrease copper absorption.

Zinc is a trace elements or a micronutrient. It means it is required in low amounts to the body. It is also an essential element required by the body. We intake zinc through diet, form the vegetables and fruits, stating their importance in diet.

The body receives around 20 to 40% of the zinc from the food. Calcium is also a trace essential element required by the body. Several studies intake decrease in copper absorption on excess zinc. Calcium is required for vitamin D synthesis and bones. Zinc is required for better metabolism, immune system through enzyme function.

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A buffer solution containing 2.0 M acetic CH3COOH and 2.0 M of sodium acetate ion has a pH of 0.4ml.

What three kinds of buffer are there?

The caco3 acid buffer, the buffer ( ph, as well as the buffering of plasma make up your body's chemical buffer system. The first buffer is typically seen as being the most crucial since it is connected to the respiratory system, even though the second buffer is the most abundant.

What are buffer and pH with an example?

The pH of an acetic and sodium acetate solution in water is equivalent at 4.74. These solutions have a pH that is under seven. These solutions are made up of a salt of the a weak acid plus

Briefing:

To solve this the formula to use is

acetate=c1+v1/v2

Where c1 = 0.50 acetate ion

v1 = 8 ml of sodium acetate

v2 = 8 ml + 2 ml = 10 ml

When we out the values into the formula above we would have

= 0.5 x 0.8

= 0.4 M

The concentration of acetate ion in the buffer solution is equal to 0.4ml

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To make the leaving group and the nucleophile anti-periplanar to one another, the carbon-carbon bond is rotated. The epoxide is created by intramolecular SN2.

The study of a molecule's three-dimensional structure is known as stereochemistry. The sole structural difference between the cis and trans isomers, which are types of stereoisomers, is where the atoms of the molecule are situated in three dimensions. These stereoisomers may differ in their chemical and physical characteristics.

Stereocenters have a R or S designation: The enantiomers of a chiral substance are referred to by the terms "right hand" and "left hand" in naming.

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We can get the solubility at temperatures from this  experimental curve. we can find the solubility at 10∘C and 100∘C temperature. Hence, NH4Cl can be dissolved in 100 mL of H2O at 10∘C is 34g and at 100∘C is 75g.

Answer and justification Salt made from ammonia and chlorine gas is known as ammonium chloride. It is a salt of strong acid (HCl) and weak base (NH4OH) (N H 4 O H). Although the process is endothermic, meaning it requires a temperature increase, the ammonium chloride salt is soluble in water.

Saline Solution.a mixture in which the solute dissolves until it is no longer able to do so, leaving the undissolved components at the bottom. Solution without saturation. a solution that totally dissolves and leaves no residues (but contains less solute than the saturated solution). Solution with a high saturation.

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The complex known as RIBOSOME, which is made up of enzymes and ribosomal RNA, is where translocation peptide has indeed been generated.

What age is the ideal time to begin taking peptides?

Since collagen production normally slows down in your mid-20s to early-30s, I advise incorporating a peptide into your skincare regimen about this time. But regardless of your age, incorporating a peptide into your skincare regimen will make your skin look younger.

Peptide vs. protein: what are they?

In general, small chains of more than two amino acids are referred to as peptides. Proteins, commonly known as polypeptides, are lengthy molecules comprised of many peptide subunits. Enzymes (other proteins) can break down proteins into little peptide fragments.

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The characteristics of the terrestrial planet are:

The terrestrial planets can simply be defined as those planets characterized by the presence of metallic substances, mountains or even rocks. However, the major known planets are as follows:

That being said, of all these planets listed above, only those ones closest to the sun are regarded to as the terrestrial or inner planets.

The terrestrial or the inner planets are as follows:

In conclusion, we can now deduce from all explanation given above that the inner planets are very close to the sun.

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Sodium, oxygen, with phosphorus combine to generate the monoatomic substances Na2O (sodium oxide), Na3P (sodium phosphide), Na3PO3 (sodium phosphite), and Na3PO4 (sodium phosphate).

All tissues and cells require phosphorus for their growth, upkeep, and repair, as well as for the creation of DNA or RNA, the genetic building blocks. Additionally, other minerals and vitamins like vitamin D, thyroid, magnesium, and zinc need phosphorus to be balanced and used.

Extra phosphorus alters the body in ways that cause calcium to be drawn from your bones, weakening them. Additionally, harmful calcium deposits in the heart, lungs, eyes, and blood vessels are caused by elevated phosphorus and calcium levels. With time

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The net ionic equation for the reaction (if any) that occurs when aqueous solutions of sodium sulfide and iron(II) nitrate are mixed.

The answer is:-

[tex]2Na^{+}(aq) + S^{2-} + Fe^{2+} + 2NO_{3}^{-}(aq) -- > 2Na^{+}(aq) + 2NO_{3}^{-}(aq) + 2FeS(s)[/tex]

Ionic Equation:-

an ionic equation is a chemical equation in which the electrolytes in an aqueous solution are expressed as dissociated ions. Usually, this is a salt dissolved in water, where the ionic species are followed by (aq) in the equation to indicate they are in an aqueous solution.

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n=2,l=1,ml=1 n=3,l=2,ml=0 n=3,l=3,ml=2 n=4,l=2,ml=0.set of quantum numbers cannot specify an orbital.

a zone around a nucleus in an atom or molecule that can have 0–1–2 electrons, as stated theoretically. Around the nucleus, in structures known as orbitals, electrons arrange themselves into clouds. These orbitals are given numbers to represent their energy level and letters (s, p, d, and f) to represent their shape. S, P, D, and f are the four fundamental types of orbitals. Two electrons can fit into a s orbital, which is spherical in shape. There are three p orbitals, each of which is oriented differently in space but has the same fundamental geometry of a . Six electrons can fit in the p orbitals at once.

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The compound will show pentagonal pyramidal structure.

This is because the one axial plane is occupied by the lone pair of electrons obeying the bent's rule . And the other 4 bond pairs are present in both equatorial and the axial position. Since a lone pair of electrons are present they represent pentagonal bipyramidal structure to pentagonal pyramidal structure.

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The atomic number of gold is 79. The correct response for an atom on the periodic table with the same number of protons and electrons is gold, which has 79 protons and 79 electrons.

Every atom has a proton in its nucleus, a subatomic particle. The particle has a positive electrical charge that is the antithesis of the electron's. If a proton were isolated, it would weigh only 1.673? 10-27 kilogrammes, little less than a neutron. A stable subatomic particle known as a proton with an electric charge of +1 e and the symbols p, H+, or 1H+. Its mass is only marginally less than that of a neutron and 1836 times greater than that of an electron.

Silicon has 14 protons and 14 neutrons, for instance. It weighs 28 kilogrammes and has an atomic number of 14. Uranium's most prevalent isotope contains 146 neutrons and 92 protons. It has an atomic mass of 238 thanks to its 92 protons and 146 electrons.

The atomic number refers to the total number of protons in the nucleus of an atom. The atomic numbers of the elements are used by the Periodic Table to divide them into groupings.

The Periodic Table is used to find an element's atomic number. The atomic number is visible in the top left corner.

For instance, krypton has an atomic number of 36. This reveals that the nucleus of a krypton atom contains 36 protons.

Atoms are not electrically charged by nature. The protons' positive charges and the electrons' negative charges must be equal.

Protons and electrons must be present in an equal number in an atom. In our example, an atom of krypton needs to have 36 protons in addition to 36 electrons.

For any component:

Atomic number = number of protons + number of electrons

Hence, as an illustration of glod:

The atomic number of gold is 79. Gold therefore contains 79 protons and 79 electrons.

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The balanced complete ionic equation for the reaction between Cs₃PO₄ and AgNO₃ is:

Cs₃PO₄(aq) + 3Ag⁺(aq) + 3NO₃⁻(aq) → 3Ag₃PO₄(s) + 3NO₃⁻(aq) + 3Cs⁺(aq)

Ionic equations are defined as the balanced chemical equations that represent the species (ions or molecules) that are involved in a reaction.

In this reaction:

Cs₃PO₄(aq) + 3Ag⁺(aq) + 3NO₃⁻(aq) → 3Ag₃PO₄(s) + 3NO₃⁻(aq) + 3Cs⁺(aq)

Cs₃PO₄ (cesium phosphate) and AgNO₃ (silver nitrate) are mixed in aqueous solution. The cesium phosphate dissociates into its constituent ions, Cs⁺ and PO₄³⁻.

The silver nitrate dissociates into Ag⁺ and NO₃⁻ ions. The Ag⁺ ions react with the PO₄³⁻ ions to form solid silver phosphate (Ag₃PO₄), which is insoluble in water. The Cs⁺ and NO₃⁻ ions remain in solution.

Therefore, Cs₃PO₄(aq) + 3Ag⁺(aq) + 3NO₃⁻(aq) → 3Ag₃PO₄(s) + 3NO₃⁻(aq) + 3Cs⁺(aq) is the balanced complete ionic equation shows that a reaction takes place between cesium phosphate and silver nitrate to form solid silver phosphate and aqueous cesium and nitrate ions.

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Answer:

total of 131 millimeters of mercury

Explanation:

So we can calculate the total vapour pressure using the equation. The total pressure p equals x a where x is the mole fraction of a and the p a is the partial pressure of a plus x b being the mule fraction of b and the partial pressure of b we can get the mule fraction of a and B because 1 will equal x, a plus x b and a is hexane and b is octane, and so the mole fraction of hexane is 1.580, and so we can set this up to solve. As x b will equal 1 minus x a which is equal to 1 minus .58, which is equal to .4 2 point now, because we have all our numbers, we can put them into our full equation. So we have. The pressure is equal to .58 times. The pressure of our hexane, which is greater than 183, and this has added 2.42 and the pressure of our octane, which is 59.2, and so we get a total of 131 millimeters of mercury. As our total vapour pressure.

answer is in th epic

The pressure and the internal energy of the refrigerant at the final state

Known data:80.74kJ/kg.

[tex]$$\begin{aligned}& \mathrm{R}-134 \mathrm{a} \\& P_1=800 \mathrm{kPa} \\& T_1=25^{\circ} \mathrm{C}\end{aligned}$$[/tex]

Unknowns:

[tex]$$\begin{aligned}& T_2=? \\& u_2=?\end{aligned}$$[/tex]

The pressure of the refrigerant in the final state is equal to the saturation pressure at -20 degrees Celsius.

[tex]$$\begin{aligned}& P_2=P_{\text {sat }, \text { at }-20^{\circ} \mathrm{C}}=132.82 \mathrm{kPa} \\& P_2=132.82 \mathrm{kPa}\end{aligned}$$[/tex]

State 1 is compressed liquid. Then the enthalpy is that of the saturated liquid at 25 degrees Celsius.

[tex]\h_1=h_{f, \text { at } 25^{\circ} \mathrm{C}}=86.405 \mathrm{~kJ} / \mathrm{kg}$$[/tex]

The throttling process of the refrigerant is isentalpic. The state 2 of the refrigerant is in the phase mixing region, so we have to calculate the quality 2.

[tex]x_2=\left(h_2-h_f\right) /\left(h_g-h_f\right)$$[/tex]

Where:

[tex]$$\begin{aligned}h_2 & =h_1=86.405 \mathrm{~kJ} / \mathrm{kg} \\h_f & =25.49 \mathrm{~kJ} / \mathrm{kg} \\h_g & =238.4 \mathrm{~kJ} / \mathrm{kg}\end{aligned}$$[/tex][tex]$$\begin{aligned}h_2 & =h_1=86.405 \mathrm{~kJ} / \mathrm{kg} \\h_f & =25.49 \mathrm{~kJ} / \mathrm{kg} \\h_g & =238.4 \mathrm{~kJ} / \mathrm{kg}\end{aligned}$$[/tex]

Substituting:

[tex]x_2=(86.405-25.49) /(238.4-25.49)=0.2861$$[/tex]

Now let's calculate the final internal energy of the refrigerant, remembering that the temperature is -[tex]$20 \mathrm{C}$[/tex].

[tex]u_2=u_f+x_2\left(u_g-u_f\right)$$[/tex]

Where :

[tex]$$\begin{aligned}& u_f=25.39 \mathrm{~kJ} / \mathrm{kg} \\& u_g=218.34 \mathrm{~kJ} / \mathrm{kg}\end{aligned}$$[/tex]

Substituting :

[tex]$$u_2=25.39+0.2861(218.84-25.39)=80.74 k J / k g$$[/tex]

[tex]$$u_2=80.74 \mathrm{~kJ} / \mathrm{kg}$$[/tex]

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A molecule's formal charge is the total of the formal charges of each of the constituent atoms that make up that particular molecule.

What is the Lewis structural rule?

Hydrogen atoms can only make one bond, and they are always located at the ends of atom chains. Hydrogen is usually associated with carbon, nitrogen, or oxygen. Oxygen atoms normally do not bond to one another, with the exception of O2, O3, superoxides, and peroxides.

Describe Lewis's structure with an example.

The octet rule, which states that atoms share electrons so that each has eight in its outer shell, is the foundation of a Lewis structure. For instance, the outer shell of an oxygen atom has six electrons.

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alpha polonium crystallizes in a simple cubic unit cell with an edge length of 336 pm, the density becomes 7.318 g/cm³.

The smallest repeating unit with complete crystal structural symmetry is designated as a unit cell. The unit cell geometry, sometimes referred to as a parallelepiped, provides six lattice parameters, which are the lengths of the cell edges (a, b, and c) and the angles at which they are spaced apart ( α,β,γ ).

Given that,

alpha polonium crystallizes in a simple cubic unit cell with an edge length (a) of 336 pm.

As we know, the relation between radius (r) and edge length (a) for simple cubic unit cell is: 2 r = a

Thus, r = a/2

r = 336/2   [ given a = 336 pm]

r = 168 pm

Now, density (d) = (Z × M) / a³ × [tex]N_A[/tex]

Here, Z = number of atom in a simple cubic unit cell = 1

M = molecular weight of polonium

[tex]N_A[/tex] = Avogadro's no.

d = ( 1  × 209) / (168 ×10⁻¹²)³ × (6.023 × 10²³)

d = 7.318 × 10⁷ g/m³

d =  7.318 g/cm³

So, the density of alpha polonium is 7.318 g/cm³.

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The coefficients before Ni and H+ are 4 and 10 respectively.

A coefficient is an integer that is written or multiplied by a variable. A quantitative value multiplies variables and can change depending on other variables or covariates. Function coefficients are different from other coefficients in that they are constant across all entities or participants, while others can vary.

Coefficients are multiplicative coefficients in terms of a polynomial series, or expression. Usually numeric, but can be any expression. If the coefficients themselves are variables they can also be called parameters. Circle the variable with the power of the coefficient you found. Leave that variable and consider any other number or variable written to it. that will be the coefficient.

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Five molecules of hydrogen peroxide to two molecules of permanganate make up the mole ratio. Using the ratio, 0.0045 moles of potassium permanganate oxidised 0.005625 moles.

Materials

Distilled or deionized water, 100 mL

Hydrogen peroxide, H202, commercial antiseptic solution, 3 mL

Potassium permanganate solution, KMn04, 0.025 M, 75 mL

Sulfuric acid solution, H2SO4, 3 M, 30 mL

Beaker, I 00-or 150-mL

Buret, 50-mL, with buret clamp

Graduated cylinder, 10-or 25-mL

Labels and/or markers

Pipet, serological, 1-mL

Pipet bulb

Ring stand

Wash bottle

Waste disposal beaker, 250-mL

Erlenmeyer flask, 125-mL

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The monosaccharides to build each of the disaccharides are:

Glucose + fructose = sucrose

Galactose + glucose = lactose

glucose + glucose = maltose

What are monosaccharides examples?

The simplest carbohydrates, also called simple sugars, are plentiful in fruits. A monosaccharide is a carbohydrate consisting of one sugar unit.

What are the 4 monosaccharides?

Glucose is the most abundant monosaccharide. Galactose, mannose, fructose, and ribose are also of major biological importance.

What are the 3 disaccharides?

Disaccharides consist of two monosaccharide units, linked together with glycosidic bonds in the α or β orientation. The most important of them are sucrose, lactose, and maltose.

What are disaccharides and their functions?

Disaccharides act as an energy source for the body, just like any other carbohydrate. When we eat foods that contain disaccharides, our bodies break them down into simple sugars (monosaccharides) for absorption in the small intestine.

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Compared to a typical chemical reaction, the energy released in this nuclear reaction is more than 100,000 times larger.

How much more energy is produced by nuclear reactions compared to chemical ones?

When compared to the energy produced by the interaction of atoms, the energy released by nuclei is a million times more dense (chemical reactions). This is what causes nuclear weapons to be so much more powerful and obliterative than conventional weapons.

Is nuclear power more powerful than chemical power?

Compared to the energies involved in chemical reactions, the energies produced in nuclear reactions are several orders of magnitude higher.

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At 102°C - 106°C tetra-n-butylammonium bromide, tbab, is removed from the reaction mixture.

Facts about tetra-n-butylammonium bromide or TBAB

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It is given that its a combustion reaction, we know that the ending compounds are CO2 and H2O alone.  To get this, we add O2 in a combustion reaction to our initial compound.

C8H18 + O2  --->  CO2 + H2O  ( + trace amounts of C8H18 left)  We are asked about the C8H18 left meaning we have a limiting reactant and it is not completely water and CO2 left due to the limiting reagent.  So we are trying to find the excess reactant.  

To balance the equation we must balance all molecules ;

2 C8H18 + 25 O2  --->  16 CO2  +  18 H2O   (not taking into account the combustion of air)

It is given that it is incomplete combustion so we must use the grams of product to calculate the amount of reactant used due to the limiting reagent

1.15 g H2O * ( 1 mol H2O / 18.01532 g H2O)  *( 2 mol C8H18 / 18 mol H2O) * ( 1 mol C8H18 / 114.24 g C8H18) = 0.00111755 = 0.00118 g C8H18  reacted

11.8 g C8H18 in the initial reaction,  0.0118 g reacted to get 1.15 g H2O

11.8-0.00118 = 11.79882 = 11.8 g C8H18 left in the balanced equation (meaning almost none of it was reacted)

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