calculate the mass percentage composition of urea

Given: . Molecules of this compound are comprised of 13 carbon atoms, 18 hydrogen atoms, and 2 oxygen atoms. { "15.01:_Definitions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.02:_Solution_Concentration_-_Molarity" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.03:_Solution_Concentration_-_Molality_Mass_Percent_ppm_and_ppb" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.04:_Dilutions_and_Concentrations" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.05:_Concentrations_as_Conversion_Factors" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.06:_Acid-Base_Titrations" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15.07:_Normality" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "01:_What_Is_Chemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "02:_Measurements" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "03:_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "04:_Atoms_Molecules_and_Ions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.11:_Electronic_Structure" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.12:_Chemical_Bonds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.13:_Gases" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.5:_Nomenclature" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.6:_Chemical_Reactions_and_Equations" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.7:_Types_of_Chemical_Reactions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.8:_Stoichiometry_and_the_Mole" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "1.9:_Using_Moles_in_Chemical_Equation_StoichiometryNew_Page" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "10:_Introduction_to_Energy" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "14:_Solids_and_Liquids" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15:_Solutions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "16:_Acids_and_Bases" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "17:_Chemical_Equilibrium" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "18:_Oxidation_and_Reduction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "19:_Nuclear_Chemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "21:_Biochemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, 15.03: Solution Concentration - Molality, Mass Percent, ppm and ppb, [ "article:topic", "license:ccbyncsa", "licenseversion:40" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FCourses%2FLos_Angeles_Trade_Technical_College%2FChem_51%2F15%253A_Solutions%2F15.03%253A_Solution_Concentration_-_Molality_Mass_Percent_ppm_and_ppb, $ \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}$ $ \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} $$\newcommand{\id}{\mathrm{id}}$ $ \newcommand{\Span}{\mathrm{span}}$ $ \newcommand{\kernel}{\mathrm{null}\,}$ $ \newcommand{\range}{\mathrm{range}\,}$ $ \newcommand{\RealPart}{\mathrm{Re}}$ $ \newcommand{\ImaginaryPart}{\mathrm{Im}}$ $ \newcommand{\Argument}{\mathrm{Arg}}$ $ \newcommand{\norm}[1]{\| #1 \|}$ $ \newcommand{\inner}[2]{\langle #1, #2 \rangle}$ $ \newcommand{\Span}{\mathrm{span}}$ $\newcommand{\id}{\mathrm{id}}$ $ \newcommand{\Span}{\mathrm{span}}$ $ \newcommand{\kernel}{\mathrm{null}\,}$ $ \newcommand{\range}{\mathrm{range}\,}$ $ \newcommand{\RealPart}{\mathrm{Re}}$ $ \newcommand{\ImaginaryPart}{\mathrm{Im}}$ $ \newcommand{\Argument}{\mathrm{Arg}}$ $ \newcommand{\norm}[1]{\| #1 \|}$ $ \newcommand{\inner}[2]{\langle #1, #2 \rangle}$ $ \newcommand{\Span}{\mathrm{span}}$$\newcommand{\AA}{\unicode[.8,0]{x212B}}$, status page at https://status.libretexts.org. Atomic Mass # of Atoms Mass Percent; Carbon: C: 12.0107 g/mol: 1: 19.9994%: Hydrogen: H: 4.0318 g/mol: 4: 6.7134% . Copyright 2017-2023ezcalc.me. \%\ce O&=35.52\% \nonumber Explanation: Aluminum oxide exists as a chemical compound of aluminum and oxygen with the The formula for this compound indicates it contains Al3+ and SO42 ions combined in a 2:3 ratio. \%\ce H&=\mathrm{\dfrac{8\:mol\: H\times molar\: mass\: H}{molar\: mass\:\ce{C9H18O4}}\times 100=\dfrac{8\times 1.008\:g/mol} \nonumber {180.159\:g/mol}\times 100=\dfrac{8.064\:g/mol}{180.159\:g/mol}\times 100} \nonumber\\ (m is the abbreviation for molality) 7. dinitrogen pentoxide. It is abbreviated as w/w%. Enter your answers numerically separated by a comma. Here, we need to find the vapor pressure of urea corresponding to the water vapor pressure. Necessary cookies are absolutely essential for the website to function properly. Sign up for wikiHow's weekly email newsletter. This same approach may be taken considering a pair of molecules, a dozen molecules, or a mole of molecules, etc. Example 1: The mass of hydrogen in the compound is 2.01588 g/mol (the mass of two moles of hydrogen atoms). Element : Symbol : Atomic Mass # of Atoms : Mass Percent: Hydrogen: H: 1.00794: 4: 6.713%: Carbon: C: 12.0107: 1: 19.999%: Nitrogen: N: 14.0067: 2: 46.646%: Oxygen: O: 15.9994: 1: 26.641%: . For covalent substances, the formula represents the numbers and types of atoms composing a single molecule of the substance; therefore, the formula mass may be correctly referred to as a molecular mass. In order to calculate the mass percentage, you must know how much salt was added to a certain amount of water. For a solution, mass percent equals the mass of an element in one mole of the compound divided by the molar mass of the compound, multiplied by 100%. These cookies ensure basic functionalities and security features of the website, anonymously. Concept #1: Mass Percent Concept. She has conducted survey work for marine spatial planning projects in the Caribbean and provided research support as a graduate fellow for the Sustainable Fisheries Group. Calculate the percentage composition of each element in urea CON2H4 (C=12 N=14 O=16 and H=1) - 20259371. . When a compounds formula is unknown, measuring the mass of each of its constituent elements is often the first step in the process of determining the formula experimentally. Mg2+ = 0.66 M; NO3 = 1.32 M; total: 1.98 M. 15.03: Solution Concentration - Molality, Mass Percent, ppm and ppb is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts. Answer. percent by mass formula - For a solution, mass percent equals the mass of an element in one mole of the compound divided by the molar mass of the compound, multiplied by . It does not store any personal data. How do you calculate atomic mass from isotopic composition ? Using the lower indices in the formula, the mass of each element in one mole of the compound is first calculated. Compound Moles Weight, g (NH2)2CO(urea) Elemental composition of (NH2)2CO(urea) Element Symbol Atomic weight Atoms Mass percent; Carbon: C: 12.0107: 1: 19.9994: Oxygen: O: 15.9994: 1: . 48.00 g (3 mole x 16.00 gram per mole) of O, mass % Na = 22.99 g / 84.01 g x 100 = 27.36 %, mass % H = 1.01 g / 84.01 g x 100 = 1.20 %, mass % C = 12.01 g / 84.01 g x 100 = 14.30 %, mass % O = 48.00 g / 84.01 g x 100 = 57.14 %, 32.00 g (2 mol x 16.00 gram per mole) of O, mass % C = (mass of 1 mol of carbon/mass of 1 mol of CO, mass % O = (mass of 1 mol of oxygen/mass of 1 mol of CO. You won't always be given the total mass of a mixture or solution. Now, we can useAvogadros number and formula mass (also called molecular weight)to convent between mass of a sample, moles, and number of molecules. In this case, several readers have written to tell us that this article was helpful to them, earning it our reader-approved status. (b) Calculate the mass percentage of nitrogen, phosphorus, and potassium for each of the compounds in part (a). It means the total mass if 1 molecule of urea = 12+16+28+4=60. For example, consider a gaseous compound composed solely of carbon and hydrogen. H2O) as well as denoted using the tiny numbers, like or , (e.g. Were committed to providing the world with free how-to resources, and even $1 helps us in our mission. To calculate percent composition, we divide the experimentally derived mass of each element by the overall mass of the compound, and then convert to a percentage: % C = 7.34 g C 12.04 g compound 100% =61.0% % C = 7.34 g C 12.04 g compound 100 % = 61.0 %. Here the molar mass of: N = 14 u. In an earlier chapter, we described the development of the atomic mass unit, the concept of average atomic masses, and the use of chemical formulas to represent the elemental makeup of substances. H2O for a water molecule. . Temperature of water = 30C . What is the molarity of a solution made by dissolving 13.4 g of NaNO3 in 345 mL of solution? Often, you'll need to add up the masses. Bicarbonate of soda (sodium hydrogen carbonate) is used in many commercial preparations. The results of these measurements permit the calculation of the compounds percent composition, defined as the percentage by mass of each element in the compound. Example $\PageIndex{9}$: Deriving the Number of Molecules from the Compound Mass. Calculate the amount of water (in grams) that must be added to each of the following substances to produce the indicated solution. To learn how to calculate mass percent when you don't know any of the masses involved, read on! We can derive the number of moles of a compound from its mass following the same procedure we used for an element in Example $\PageIndex{6}$: The molar mass of glycine is required for this calculation, and it is computed in the same fashion as its molecular mass. For instance, if you added 50 grams of NaCl to 1000 grams of water, that mass percent would be 50/1050 x 100 = 4.76%. Fertilizers supply the essential elements, nitrogen, phosphorus and potassium for plant growth. The percent composition of this compound could be represented as follows: \[\mathrm{\%H=\dfrac{mass\: H}{mass\: compound}\times100\%}\]. Example $\PageIndex{8}$: Deriving Grams from Moles for a Compound. Our site uses cookies to improve your experience, to analyze traffic and to personalize ads. Its formula mass is 58.44 amu. Indeed, having determined the percent composition of an unknown substance, it can be compared to the percent composition of a known compound in order to identify it. Using the definition of mass percentage, we have, \[\%m/m\: =\: \frac{87.9\, g\, Fe}{113\, g\, sample}\times 100\%=77.8\%\, Fe\]. 46.6% So, the percentage of nitrogen present in the urea is 46.6%. Accessibility StatementFor more information contact us [email protected] check out our status page at https://status.libretexts.org. Divide mass of the chemical by mass of the compound and multiply by 100: 5.8/50.8 x 100 = 11.42%. To do this, grams; multiply the mass of the compound by a conversion factor based on the percent composition of the element in the compound. Note- The molar mass of nitrogen is 14.0 g/mol, the molar mass of hydrogen is 1.00 g/mol, the molar mass of sulfur is 32.0 g/mol, and the molar mass of oxygen is 15.9 g/mol. Table 1. Solution for Calculate the percent composition by mass of all the elements in urea, (NH2)2CO. A molecule of NH3 contains one N atom weighing 14.01 amu and three H atoms weighing a total of (3 1.008 amu) = 3.024 amu. This article was co-authored by Bess Ruff, MA. This constant is properly reported with an explicit unit of per mole, a conveniently rounded version being $6.022 \times 10^{23}/\ce{mol}$. (5/105) x 100 = 0.04761 x 100 = 4.761% . After doing so, it figures out the atom percent . =\mathrm{1.31\times10^{20}\:\ce{C7H5NO3S}\:molecules}\]. This cookie is set by GDPR Cookie Consent plugin. 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. What is the percentage of N in urea? Retrieved from https://www.thoughtco.com/mass-percent-composition-example-609567. \end{align*}\], \[\begin{align*} Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. 22 System of Linear Equations Calculator, 33 System of Linear Equations Calculator, Simplifying Radical Expressions Calculator. The chemical formula is (NH4)2SO4 ( N H 4) 2 S O 4 (ammonium sulfate) We need to calculate the mass percent of sulfur in the given compound. To calculate the percentage composition of an element in a compound, we use the equation: In 1 mole of urea, 2 moles of nitrogen atoms are there. These cookies will be stored in your browser only with your consent. Mass percent is also known as percent by weight or w/w%. Parts per thousand is defined as follows: \[ppth\: =\: \frac{mass\: of\: solute}{mass\: of\: sample}\times 1000\]. 2. Multiplying each element by its subscript gives you: Example 1: Add 2.01588 g/mol (the mass of two moles of Hydrogen atoms) with 15.9994 g/mol (the mass of a single mole of Oxygen atoms) and get 18.01528 g/mol. Mass percent composition is also known percent by weight. are required to dissolve 25.0 g of urea (CO(NH 2) 2) in order to produce a solution that is 1.65 m? ThoughtCo, Aug. 28, 2020, thoughtco.com/mass-percent-composition-example-609567. Knowing the percent composition of a compound allows you to determine the appropriate amounts of each element needed to synthesize it. If a solution is prepared by mixing 50 ml of vinegar into 300 ml of solution, what is the percentage by volume? Following the approach outlined above, the formula mass for this compound is calculated as follows: Calcium phosphate, Ca3(PO4)2, is an ionic compound and a common anti-caking agent added to food products. Molar mass of (NH2)2CO is 60.0553 g/mol. This approach is perfectly acceptable when computing the formula mass of an ionic compound. Ibuprofen, C13H18O2, is a covalent compound and the active ingredient in several popular nonprescription pain medications, such as Advil and Motrin. Use the definition of parts per thousand to determine the concentration. Videos in Mass Percent. Molar mass of N = 14.0067 g/mol. Let's see how you could calculate mass percent for any element or a chemical solution with the assistance of this percent by mass calculator. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. This website uses cookies to improve your experience while you navigate through the website. ", "The problems are solved step by step, which helps the readers understand things better.". To calculate the mass percent of an element in a compound, we divide the mass of the element in 1 mole of the compound by the compound's What is the mass percentage of H2O2 in a solution with 1.67 g of H2O2 in a 55.5 g sample? As a small thank you, wed like to offer you a $30 gift card (valid at GoNift.com). These ideas can be extended to calculate the formula mass of a substance by summing the average atomic masses of all the atoms represented in the substances formula. The cookie is used to store the user consent for the cookies in the category "Analytics". Your years and months of creditable service. Percent composition = molar mass of an element/molecular mass of the compound. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". Solution for Calculate the composition of the following solution in mass/mass %: 59.0 g KCl per 3.00 102 ml solution (d = 1.14 g/mL) Example 2: Add all of the calculated molar masses together: Carbon + Hydrogen + Oxygen = 72.0642 + 12.09528 + 95.9964 = 180.156 g/mol. The model shows the molecular structure of chloroform. Its Formula is Con2h4. wikiHow marks an article as reader-approved once it receives enough positive feedback. Step 1: Find the mass of the individual atoms. Its formula is NaHCO3. Percentage nitrogen by mass= (Molar mass of nitrogen)/ (Molar mass of ammonium sulfate)*100. \%\ce H&=4.476\,\%\,\ce H\nonumber These cookies track visitors across websites and collect information to provide customized ads. But what if the chemical formula of a substance is unknown? Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. The sum of all the mass percentages should add up to 100%. This online Percent Composition Calculator finds the elemental composition as well as the percentage distribution of the number of atoms and their masses for a molecule given its chemical formula. The total mass of the compound is the amount of sodium hydroxide plus the amount of water: 100g + 5g for a total mass of 105g. What are the individual ion concentrations and the total ion concentration in 1.04 M Al2(SO4)3? Thus, the mass percent of Hydrogen atoms in a water molecule is 11.18%. The formula mass of a substance is the sum of the average atomic masses of each atom represented in the chemical formula and is expressed in atomic mass units. Approved. One of these amino acids is glycine, which has the molecular formula C2H5O2N. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. View solution. Find the mass percentages (mass %) of Na, H, C, and O in sodium hydrogen carbonate. It will calculate the total mass along with the elemental composition . If the C2H3O2 ion concentration in a solution is 0.554 M, what is the concentration of Ca(C2H3O2)2? Calculate the mass % of solute. Ionic compounds are composed of discrete cations and anions combined in ratios to yield electrically neutral bulk matter. Step 1: Analyze the formula to find percentage composition. The molecular formula of Urea= NH 2 CONH 2. What is the formula mass (amu) of this compound? Additional Information: Urea has another name called carbamide. How would I calculate the mass percent of a MgBr2 solution that contains 5.80g of MgBr2 in 45.0g of solution? Example 2: Look up the molecular weight of Carbon, 12.0107; Oxygen, 15.9994; and Hydrogen, 1.0079. Percent composition of nitrogen in fertilizer. For a solution, mass percent equals the mass of an element in one mole of the compound divided by the molar mass of the compound, multiplied by 100%. Solving for Mass Percent When Given Masses, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/a\/a2\/Calculate-Mass-Percent-Step-1.jpg\/v4-460px-Calculate-Mass-Percent-Step-1.jpg","bigUrl":"\/images\/thumb\/a\/a2\/Calculate-Mass-Percent-Step-1.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/d\/d3\/Calculate-Mass-Percent-Step-2-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-2-Version-3.jpg","bigUrl":"\/images\/thumb\/d\/d3\/Calculate-Mass-Percent-Step-2-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-2-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/e\/ec\/Calculate-Mass-Percent-Step-3-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-3-Version-3.jpg","bigUrl":"\/images\/thumb\/e\/ec\/Calculate-Mass-Percent-Step-3-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-3-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/b\/ba\/Calculate-Mass-Percent-Step-4-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-4-Version-3.jpg","bigUrl":"\/images\/thumb\/b\/ba\/Calculate-Mass-Percent-Step-4-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-4-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/44\/Calculate-Mass-Percent-Step-5-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-5-Version-3.jpg","bigUrl":"\/images\/thumb\/4\/44\/Calculate-Mass-Percent-Step-5-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-5-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, Solving for Percent Mass When Not Given Masses, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/0\/0f\/Calculate-Mass-Percent-Step-6-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-6-Version-3.jpg","bigUrl":"\/images\/thumb\/0\/0f\/Calculate-Mass-Percent-Step-6-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-6-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

License: Creative Commons<\/a>
\n<\/p>

\n<\/p><\/div>"}, {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/f\/ff\/Calculate-Mass-Percent-Step-7-Version-3.jpg\/v4-460px-Calculate-Mass-Percent-Step-7-Version-3.jpg","bigUrl":"\/images\/thumb\/f\/ff\/Calculate-Mass-Percent-Step-7-Version-3.jpg\/aid2931007-v4-728px-Calculate-Mass-Percent-Step-7-Version-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"