Our experts can answer your tough homework and study questions. \ Al(OCH_3)_3 \\ B. Example \(\PageIndex{4}\): Ethylene Glycol, For 35.00 g of ethylene glycol (HOCH2CH2OH), which is used in inks for ballpoint pens, calculate the number of, Asked for: number of moles and number of molecules. Calculate the number of carbon atoms in 49.0 g of ethanol, C2H6O. Please enable JavaScript in order to use this website. E) 0.22. Calculate the mass of 1.75 mol of each compound. This program determines the molecular mass of a substance. The definition of a molethat is, the decision to base it on 12 g of carbon-12is also arbitrary. A The empirical formulaCa3(PO4)2indicates that the simplest electrically neutral unit of calcium phosphate contains three Ca2+ ions and two PO43 ions. The formula weight of ethanol (C2H5OH) is , Formula weight of C2H5OH= (12 x 2) + (6 x 1) + (1 x 16). To obtain the mass of 1 mole of water, look up the atomic masses for hydrogen and oxygen from the Periodic Table. Between water, ethanol, and isopropanol, which has the largest molar mass? How much of the following do you have? Calculate the molar mass of C6H12O6 (glucose). the theoretical yield of an experiment. When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. 4.21 x 10^-4 g/cm3 B. The molecular mass = 116.0 amu. Then copy and save the url. A) 2.3. The molar mass of S2Cl2 is 135.036 g/mol. 0 0 Similar questions The empirical formula of a compound is CH 2O. Calculate the percent by mass of the element listed first in the formula for the compound ethanol, C2H5OH. What mass of ethanol can be made from 1.00kg of sugar? process. There is 133 g of a substance in 1 L. The molecular weight of the substance is 58.5 g/mol, What is the mol fraction? B Convert from moles to mass by multiplying the moles of the compound given by its molar mass. What is the name for the following compound: Fe3(PO4)2? What is the meaning of the two (2) in ethyl alcohol C2H5OH? Calculate the molecular or formula mass for H2O. Definitions of molecular mass, molecular weight, molar mass and molar weight. (1 u is equal to 1/12 the mass of one atom of carbon-12) Which gas molecules have the higher average speed and what is . Convert from moles to molecules by multiplying the number of moles by Avogadros number. Updated on July 03, 2019 Molecular weight is a measure of the sum of the atomic weight values of the atoms in a molecule. Solved The molecular weight of ethanol (C2H5OH) is 46.1 and - Chegg Answer the following question about the compound C_2H_8N_2. The molar mass of ethanol (C2H5OH), the alcohol in alcoholic beverages, is g/mol. Molecular weight of KBr - Convert Units Determine the molecular formula of a molecule having an empirical formula of NH2 and a molar mass of 32 g/mol. Calculate the molar mass of C_5H_2O_5. Molar mass of ethanol (C2H5OH) is:(Atomic masses: C = 12 u, H - Toppr Molar Mass of C2H5OH (Ethyl Alcohol) - ModCalculator Add the weight of the atoms in the molecule and you have the molar mass for the molecule. calculate the molecular mass of C2H5OH - Brainly.in massMol. How would you convert the molar mass of ethyl butyrate (116.14 g/mol) to grams? The atomic mass unit is used to express it (u). Formula weights are especially useful in determining the relative weights of reagents and products in a chemical reaction. How many hydrogen atoms exists in 10.0 mg ethanol? A mole is defined as the amount of a substance that contains the number of carbon atoms in exactly 12 g of isotopically pure carbon-12. (Mg atomic mass = 24.31g) A. The molar mass of a substance is the mass in grams of 1 mole of the substance. Questions Tips & Thanks Determine the molar mass of Cu3(PO4)2. a. Symbol: O A compound that is composed of only carbon and hydrogen contains 85.7% C and 14.3% H by mass. Ethanol has a chemical formula of C_2H_6O. One mole of carbon still has 6.022 1023 carbon atoms, but 98.89% of those atoms are carbon-12, 1.11% are carbon-13, and a trace (about 1 atom in 1012) are carbon-14. It is always a good idea to estimate the answer before you do the actual calculation. Fibonacci Sequence (a) 159.62 g/mol (b) 249.70 g/mol (c) 177.64 g/mol (d) 185.72 g/mol (e) 446.48 g/mol. Among its many uses, ethanol is a fuel for internal combustion engines. Use the term molecular mass to describe the difference between gasoline and kerosene. Calculate the number of H atoms present in 0.5 moles of C2H5OH. Calculate the molar mass of Ca(BO2)2 6H2O. set up the materials in the laboratory? Calculate the mole fraction of ethyl alcohol, C_2H_5OH, in a solution that contains 230.0 grams of C_2H_5OH and 312 grams of benzene, C_6H_6. But how would you or. Accessibility StatementFor more information contact us atinfo@libretexts.org. The molar mass of C2H5OH (Ethyl Alcohol) is: 46.069 grams/mol. (Choose the best answer.) The units of measurement of the molecular mass are amu, the same unit as for the atomic masses of the elements. Molar Mass / Molecular Weight of C2H5OH : Ethanol - YouTube The shaded spheres have a molecular mass of 32 amu. Advertisement Advertisement rameshvaliyarampath rameshvaliyarampath Answer: 46 u. You can also share results with a study partner or tutor by hitting calculate and copying the URL for this page. Round your answer to 2 decimal places. the molar mass of a chemical compound based on the compound's empirical formula. These weights may vary significantly from molecular The unit that provides this link is the mole (mol), from the Latin moles, meaning pile or heap.. The average mass of a monatomic ion is the same as the average mass of an atom of the element because the mass of electrons is so small that it is insignificant in most calculations. Example \(\PageIndex{2}\): Formula Mass of Calcium Phosphate. B) 0.55. The procedure for calculating molecular masses is illustrated in Example \(\PageIndex{1}\). This project started with as a molar mass calculator for chemical reactions. It is calculated by adding together the atomic masses of the elements in the substance, each multiplied by its subscript (written or implied) in the molecular formula. All rights reserved. A. For the combustion of butane (\(C_4H_{10}\)) the balanced equation is: \[2C_4H_{10(l)} + 13O_{2(g)} \rightarrow 8CO_{2(g)} + 10H_2O_{(l)}\]. (1 u is equal to 1/12 the mass of one atom of carbon-12) To analyze the transformations that occur between individual atoms or molecules in a chemical reaction, it is therefore essential for chemists to know how many atoms or molecules are contained in a measurable quantity in the laboratorya given mass of sample. A) mu * M B) mol/nL C) mmol/L D) mg/mu * L E) mg/L F) % (W/V). Molar mass of KBr = 119.0023 g/mol. Calculate the molecular weight of serotonin (C10H12N2O). The molecular \ Ga(OCH_3)_3 \\ C. \ B(OCH_3)_3 \\ D. \ (BO(OCH_3))_2. B The mass of 1.75 mol of Ca(ClO)2 is calculated as follows: Because 1.75 mol is less than 2 mol, the final quantity in grams in both cases should be less than twice the molar mass, which it is. Calculate the formula mass of Ca3(PO4)2, commonly called calcium phosphate. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. In the Round your answer to one decimal place. (Be sure to hit calculate first, however). b. A. (Atomic masses: C = 12 u; H = 1 u; O = 16 u). Any readily measurable mass of an element or compound contains an extraordinarily large number of atoms, molecules, or ions, so an extremely large numerical unit is needed to count them. The problem for Dalton and other early chemists was to discover the quantitative relationship between the number of atoms in a chemical substance and its mass. a. Calculate The Molecular Mass Of The Following: MolecularmassofH2CO3=2(H)+1(C)+3(O)=2(1)+1(12)+3(16)=2+12+48=62uMolecularmassofC2H5OH=2(C)+6(H)+1(O)=2(12)+6(1)+1(16)=24+6+16=46uMolecularmassofH2SO4=2(H)+1(S)+4(O)=2(1)+1(32)+4(16)=2+32+64=98u. If you got 100 g for the molar mass of ethanol, after calculating its molar mass in an experiment and the given molar mass of ethanol is 46.07 g, do your results say anything on whether or not hydrogen bonds can form between ethanol molecules when ethanol. Count The Number of Each Atom. Get access to this video and our entire Q&A library, Molecular Mass: Definition, Formula & Calculation. This compound is also known as Potassium Bromide. a. C6H8 b. C40H56 c. C10H16O2 d. C8H9Br e. C8H9ClO f. C7H11N g. C4H8BrN h. C10H18CINO, What is the molar mass (to the nearest tenth of a gram/mole) of KCl, given of the following. This is analogous to the fact that a dozen extra large eggs weighs more than a dozen small eggs, or that the total weight of 50 adult humans is greater than the total weight of 50 children. Stacked vertically, a mole of pennies would be 4.5 1017 mi high, or almost six times the diameter of the Milky Way galaxy. The ratio \( \left( \dfrac{2\; mol\l H_2O}{1\;mol\;O_2} \right)\) is the stoichiometric relationship between \(H_2O\) and \(O_2\) from the balanced equation for this reaction. The first step to finding the molar mass is to count the number of each atom present in a single molecule using . Using a table of atomic weights, calculate the formula weight of glucose to three significant figures. C Adding together the masses gives the molecular mass: \[ 24.022 \,amu + 6.0474 \,amu + 15.9994 \,amu = 46.069 \,amu\]. Because 1 mol of ethanol contains 2 mol of carbon atoms (2 12.011 g), 6 mol of hydrogen atoms (6 1.0079 g), and 1 mol of oxygen atoms (1 15.9994 g), its molar mass is 46.069 g/mol. Chemistry Chapter 7 Review Flashcards | Quizlet You can also ask for help in our chat or forums. The mole is so large that it is useful only for measuring very small objects, such as atoms. Molar Mass Calculator - ChemicalAid Determine the formula weight (molecular mass) of the substance bromine, Br2. The molecular weight of ethanol (C2H5OH), rounded to one decimal place, is amu. Molar mass of ethanol (C 2H 5OH) is: (Atomic masses: C = 12 u, H = 1 u, O = 16 u) A 34 B 38.9 C 46 D 45.1 E 62.1 Medium Solution Verified by Toppr Correct option is C) Molar mass of ethanol ( C 2H 5OH) =(2atomic mass of carbon)+(6 atomic mass of hydrogen)+(1atomic mass oxygen) =2(12)+6(1)+1(16)=46 g/mol The molecular weights reported elsewhere in this site are based on average atomic masses. How do you find the mass percent of ethanol? Determine its molecular formula. Calculate the mass of 0.0122 mol of each compound. Examples: C6H12O6, PO4H2(CH2)12CH3 Calculate molecular mass by: Contact help@bmrb.io if you have any questions about this site Calculate the mole fraction of ethanol in 95% by mass aqueous solution. We take the formula you provide (NaCl - common table salt - in our default example) and unpack it into the component elements. 3.4: Avogadro's Number and the Mole - Chemistry LibreTexts The atomic mass of ethanol would then be: {eq}\rm (2\times12.011)+(6\times1.007)+(1\times15.999)= 46.063\;amu What is the molar mass of ethanol (C_2H_5OH)? H 10.07%. Thus, the overall sequence of steps to solve this problem is: First of all we need to calculate how many moles of butane we have in a 1.00 gram sample: \[ (1.00\; g\; C_4H_{10}) \left(\dfrac{1\; mol\; C_4H_{10}}{58.0\;g\; C_4H_{10}}\right) = 1.72 \times 10^{-2} \; mol\; C_4H_{10}\]. For example, the mass of 1 mol of magnesium (atomic mass = 24.305 amu) is 24.305 g. Because the atomic mass of magnesium (24.305 amu) is slightly more than twice that of a carbon-12 atom (12 amu), the mass of 1 mol of magnesium atoms (24.305 g) is slightly more than twice that of 1 mol of carbon-12 (12 g). Use Avogadro's Number to Convert Molecules to Grams - ThoughtCo Molar mass of CH3OH - Chemical Portal Because we are dealing with slightly more than 0.5 mol of ethylene glycol, we expect the number of molecules present to be slightly more than one-half of Avogadros number, or slightly more than 3 1023 molecules, which is indeed the case. would be considered to be stoichiometrically equivalent quantitites. It's easy share & save results via email. elements present (driven by differences in radioactive decay and how the material was aggregated to begin with). It also describes the law of multiple proportions, which states that the ratios of the masses of elements that form a series of compounds are small whole numbers. percent yield calculator which can help you apply this to actual experiments. C To calculate the number of molecules in the sample, we multiply the number of moles by Avogadros number: \[ \text {molecules of ethylene glycol} = 0.5639 \, mol \left ( {6.022 \times 10^{23} \, molecules \over 1 \, mol } \right ) \], \[ = 3.396 \times 10^{23} \, molecules \]. One atomic mass unit (u) is equal to 1/12 the mass of one atom of carbon-12. Molar mass is an important concept in adapting chemical formulas to real world conditions. Molar mass of C5H5OH - Chemical Portal What is the mole fraction of water in 200 grams of 95 percent by mass of ethanol, C2H5OH? The first step to finding the molar mass is to count the number of each atom present in a single molecule using the chemical formula, C2H5OH(C2H5OH): Atoms; In the laboratory, for example, the masses of compounds and elements used by chemists typically range from milligrams to grams, while in industry, chemicals are bought and sold in kilograms and tons. Obtain the atomic masses of each element from the periodic table and multiply the atomic mass of each element by the number of atoms of that element. Modulo Calculator, {/eq}, {eq}\rm Molar\:Mass=46.068\:\frac{grams}{mole} Understand what the formula unit mass is, how to find molecular mass, and exercise calculating molecular mass in some example problems. The calculated answer (0.5639 mol) is indeed less than 1 mol, so we have probably not made a major error in the calculations. a. The ratio \( \left( \dfrac{2\; mol\; H_2O}{1\;mol\;O_2} \right)\) is the stoichiometric relationship between \(H_2O\) and \(O_2\) from the balanced equation for this reaction. Read our article on how to calculate molar mass. Calculate the molar mass of C2H6O (ethanol). Just as 1 mole of atoms contains 6.022 1023 atoms, 1 mole of eggs contains 6.022 1023 eggs. There are two hydrogen atoms and one oxygen for every H 2 O molecule, so the . Calculate the molar mass of C2H6O (ethanol). The important point is that 1 mole of carbonor of anything else, whether atoms, compact discs, or housesalways has the same number of objects: 6.022 1023. A chemist vaporized a liquid compound and determined its density. An alcohol is 60.00% C, 13.33% H, and 26.67% O by mass. Determine the molecular formula for a molecule that is 49.999% C, 5.595% H, 44.406% O, and has a molar mass between 210 and 225 g/mol. Calculate the molecular weight if 3.5 grams of gas occupies 2.1 L at STP. Other: Weighted Grade Calculator, Elucidate the given term. Explain in detail. Based on this, calculate the molecular weight of caffeine. Molar mass allows us to convert a chemical reaction into specific amounts of reagents required for the LCM Calculator, Similarly, the mass of 1 mol of helium (atomic mass = 4.002602 amu) is 4.002602 g, which is about one-third that of 1 mol of carbon-12. Molar mass is the mass (in atomic mass units) of one mole of a of a substance. The radius of Na atom is 186 pm and atomic number is 11. The molecular weight of a compound is the sum of all atoms present in the compound's molecular formula. mass= 4590=2 Mol. What is the molar mass (g/mol)? Mol. Examples of molecular weight computations: C[14]O[16]2, S[34]O[16]2. For example, to convert moles of a substance to mass, the following relationship is used: \[(moles)(molar mass) \rightarrow mass \tag{3.4.1}\], \[ moles \left ( {grams \over mole } \right ) = grams \]. For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass. C Adding together the masses gives the formula mass of Ca3(PO4)2: \[120.234 \,amu + 61.947522 \, amu + 127.9952 \, amu = 310.177 \, amu \]. A Calculate the molecular mass of the compound in grams from its molecular formula (if covalent) or empirical formula (if ionic). values within 0.5 units of this value. You also have the option of saving links to the calculations in your research notes files, so you can quickly re-open or check them later. (C6H5)3PCCO => C18H15PCCO. It solves for total mass of a molecular formula (average molecular weight). The percentage composition of acetaldehyde is 54.5% C, 9.2% H, and 36.3% O, and its molecular weight is 44 amu. (C_2H_5OH), Or if you were, for example, buying oxygen for a process, how would you determine how much to use The mole is a unit used to measure the number of atoms, molecules, or (in the case of ionic compounds) formula units in a given mass of a substance. Is the molecular weight of O_2 15.999u or 32? # of Atoms: 1 What is its molecular weight? to make a given quantity of water? This compound is the principal source of calcium found in bovine milk. Erythrose C4H8O4 Molar Mass, Molecular Weight. What Is Molecular Weight? Chemistry Definition - ThoughtCo The calculator takes the elemental composition of the compound and weighs the elements to get an Calculate its molecular mass. The molar mass of ethylene glycol is 62.068 g/mol. Browse by subject . This number is called Avogadros number, after the 19th-century Italian scientist who first proposed a relationship between the volumes of gases and the numbers of particles they contain. Express your answer to two decimal places and include the appropriate units. The molar mass of a substance is defined as the mass in grams of 1 mole of that substance. # of Atoms: 2 Erythrose C4H8O4 Molecular Weight -- EndMemo Ignore the question of whether or not a gas with this molecular weight actually exists. Although the mass number is unitless, it is assigned units called atomic mass units (amu). To calculate the number of atoms, molecules or formula units in a sample. conduct your search (Help): You may search for species based on molecular weight If none of the data types are checked, there 12.0107*2 + 1.00794*5 + 15.9994 + 1.00794, Element: Hydrogen Explain. (a) 94.05 g/mol (b) 71.6 g/mol (c) 142.05 amu (d) 142.05 g/mol (e) 94.05 amu; Calculate the molar mass of UF6. As discussed previosuly, the mass number is the sum of the numbers of protons and neutrons present in the nucleus of an atom. What is percent composition of ethanol ( #C_2H_5OH# )? - Socratic 114.09 amu b. Therefore, when considering this particular reaction. What is the difference between molecular weight and exact mass? Calculate the molar mass of ethylbenzene. The limits of the range should If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. Write the formula and structural formula of methanol. Empirical formula of a compound is C2H5O and its molecular weight 90 What is its probable molecular formula? 3.71 x 10^-4 g/cm3 C. 7.31 x 10^-4 g/cm3 D. 8.31 x 10^-4 g/cm3 402. b) 20 amu. It is also sometimes called: Molecular Mass, Molecular Weight, Formula Mass, or Formula Weight. Uses the formula of a reactant to determine molar mass. C2H5OH + O2 Molar Mass - ChemicalAid Add together the masses to give the formula mass. Na_2SO_4 \cdot 10H_2O(s) \\2. . In each case, the number of grams in 1 mol is the same as the number of atomic mass units that describe the atomic mass, the molecular mass, or the formula mass, respectively. Arithmetic Sequence, Any chemical element. (round the answer to 2 decimal place), The molecular weight of this organic compound is: _____. A The formula mass of Ca(ClO)2 is obtained as follows: \[1Ca (1 \, atom)(40.078 \, amu/atom) = 40.078 \, amu \], \[2Cl (2 \, atoms)(35.453 \, amu/atom) = 70.906 \, amu \], \[+ 2O (2 \, atoms)(15.9994 \, amu/atom) = 31.9988 \, amu \], \[ Ca (ClO)_2 \text { formula mass of } Ca (ClO)_2 = 142.983 \, amu\]. Factor An Integer, Mass Percent: 13.128%, Element: Carbon Atomic Mass: 12.0107 aware of dilution or impurities, make appropriate adjustments for the molarity of a given substance. - Definition, Formula & Examples. Molecular weight calculation: Convert from mass to moles by dividing the mass given by the compounds molar mass. What is the molecular wt. Atoms are so small, however, that even 500 atoms are too small to see or measure by most common techniques. Calculate the mole fractions of ethanol and water in a mixture of equal masses of water and ethanol. What Is Relative Atomic Mass / Relative Molecular Mass / Average Molecular Weight? One mole always has the same number of objects: 6.022 1023. They don't affect the weight anyhow. Calculate the molecular mass (in amu) of (NH4)2CO3. Atomic mass, molecular mass, and formula mass all have the same units: atomic mass units. Determine the number of atoms of each element in the empirical formula. The chemical formula is {eq}\rm C_2H_5OH Example \(\PageIndex{3}\): Combustion of Butane. 3.4: Avogadro's Number and the Mole is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts. Mass Percent: 34.730%. C2H5OH(C2H5OH) Molar Mass - ChemicalAid Report your answer to 2 decimal places. Calculate the molar mass of glucose, C6H12O6. What is the percent by mass of H in ethyl alcohol (C_2H_6O) ? the Calculate the mass of 169.4 moles of ethanol, C_2H_5OH. Calculate the mole fraction of C_2H_5OH in a solution that contains 84.0 grams of ethanol, C_2H_5OH, and 120.0 grams of methanol, CH_3OH. A) 22.1 g/mol B) 26.0 g/mol C) 46.07 g/mol D) 45.06 g/mol E) 29.02 g/mol. Theoretical Yield Calculator, Molecular formula determination through criss cross valency . There are 4 easy steps to find the molar mass of C2H5OH(C2H5OH) based on its chemical formula. A) 45.06 g/mol B) 34.06 g/mol C) 46.07 g/mol D) 30.03 g/mol E) 105.03 g/mol. Because the units of atomic mass are atomic mass units, the units of molecular mass are also atomic mass units. The mole is the basis of quantitative chemistry. Solution Verified by Toppr Correct option is C) Empirical formula mass of C 2H 5O=24+5+16=45. The molecular formula of glucose is C6H12O6. r1 / r2 = sqrt ( M2 / M1) where 1 denotes shaded molecule and 2 d . Calculate the molar mass of sucrose (C12H22O11). The molecular formula of caffeine is C8H10N4O2. A. From there we break the formula for Ethyl Alcohol into parts - To calculate the molecular mass of a covalent compound and the formula mass of an ionic compound, and to calculate the number of atoms, molecules, or formula units in a sample of a substances. If one or more of the data types are checked, How to calculate the molecular weight of C_{10}H_{12}O_{6}? (For more information, see Section 1.6 "Isotopes and Atomic Masses".) Until recently, it was used as a refrigerant. How to calculate the mass of a particular isotopic composition. In general, what are the steps for calculating molecular weight when you are given the molecular formula? The molar mass of a substance is defined as the mass of 1 mol of that substance, expressed in grams per mole, and is equal to the mass of 6.022 1023 atoms, molecules, or formula units of that substance. How do you find the mass percent of ethanol? 1. As shown in this video, we can obtain a substance's molar mass by summing the molar masses of its component atoms. since the two isotopes have a different atomic mass due to additional neutrons). MCQ in General Chemistry Part 9 | ECE Board Exam - Pinoybix Engineering It provides chemists with a way to convert easily between the mass of a substance and the number of individual atoms, molecules, or formula units of that substance. 1. 3.85 moles B. The molecular formula of compound is : Hard View solution > Solved Effusion of a 1:1 mixture of two gases, represented - Chegg opens up the URL, they will see your calculations. In this case, the mass given (35.00 g) is less than the molar mass, so the answer should be less than 1 mol. Atomic Mass: 1.00794 # of Atoms: 6 Mass Percent: 13.128% Element: Carbon Symbol: C Atomic Mass: 12.0107 # of Atoms: 2 Mass Percent: 52.143% Element: Oxygen Symbol: O Atomic Mass: 15.9994 # of Atoms: 1 Mass Percent: 34.730% Calculate the molecular weight of a chemical compound Enter a chemical formula: Browse the list of common chemical compounds. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula. CaSO_4 \cdot 2H_2O(s). The formula mass of ethyl alcohol is 46.069 atomic mass usnits (amu). The structure of a molecule of Freon-11 is as follows: Unlike molecules, which form covalent bonds, ionic compounds do not have a readily identifiable molecular unit. Water C. Ethanol. Potassium permanganate (KMnO4), 46 g of ethanol contains (a) 2 x 6.023 x 10^23 C atoms (b) 3 x 6.023 x 10^23 atoms (c) 9 x 6.023 x 10^23 H atoms, Calculate the mass of the following atoms in amu, (a) Helium (mass of He = 6.641 x 10^-24 g) (b) Silver (mass of Ag = 1.790 x 10^-22 g), The largest number of molecules is in (a) 54 g of nitrogen pent oxide (b) 28 g of carbon dioxide (c) 36 g of water (d) 46 g of ethyl alcohol, Which contains the greatest number of moles of oxygen atoms?