C3H8(g) + 5 O2(g) ---> 3 CO2(g) + 4 H2O(l). a. Born and raised in the city of London, Alexander Johnson studied biology and chemistry in college and went on to earn a PhD in biochemistry. These cookies track visitors across websites and collect information to provide customized ads. If the equilibrium constant for reaction X is K. What is the equilibrium constant for, Q:HCIO is a weak acid (Ka = 4.0 10-8) and so the salt NaClO acts as a weak base. c. If 0.1 mol of N2 combine with H2, what must be true about the quantity of H2 for N2 to be the limiting reactant? - One mole of an element has a mass, in grams, that is numerically equal to its relative. Which of these is correct after the reaction is complete? Molar mass of Calcium = 40.1 g/mol. (Old and urgently dear experts). Volume of water at 25.00C = 330.0 mL Answers #1 . There are two nitrogen atoms in the right side of the reaction while right side only has one nitrogen atom in the left side. Q:True or False. View this solution and millions of others when you join today! (5Dm`p_McL1`8omr e[9on&.ip@"x~652|v9diLRo9 aLfOi ionization, Q:The total mass of the atoms in the letter I above is 1.963X10-21 g. Calculate the mass, in grams, of, Q:Consider the steps in reductive amination of butanal with aniline under mildly acidic conditions., Q:Pyrethrin is a natural insecticide obtained from chrysanthemums. ammonia is oxidized as a result. What is the mole ratio of #H_2O# to #H_3PO_4# in the following chemical equation? What is the mole ratio of #Cl_2# to #C Cl_4#? How many moles of H2O could be obtained by reacting 0.75 mole of H2O2 in the reaction H2O2+H2S2H2O+S? If 15.0 g HgO decompose, how many moles of HgO does this represent? c. What volume does the amount of O2 in part b occupy if its density is 1.4 g/L? #1.20 cancel("g Al") "1 mol Al"/(26.98 cancel("g Al")) = "0.044 48 mol Al"#, #2.40 cancel("g I") ("1 mol I"_2)/(253.8 cancel("g I")) = "0.009 456 mol I"_2#. How many moles of #C# are needed to react with 0.480 mole #SO_2#? From this equation, one mole of nitrogen react e. 1.05 g, T55: El modelo de procesamiento de la informa, Medical Terminology Systems: Chapter 8 (Cardi, Chapter 7: Respiratory System Exam Study Guide, Bruce Edward Bursten, Catherine J. Murphy, H. Eugene Lemay, Matthew E. Stoltzfus, Patrick Woodward, Theodore E. Brown. You also have the option to opt-out of these cookies. Whem ammonia react with oxygen in the presence of Pt catalyst, nitric oxide (NO) and watwe are given. When 0.121 moles of HCl reacts with 0.399 moles of NH3, how much NH3 is consumed? 4 mol % This cookie is set by GDPR Cookie Consent plugin. Ammonia gas can be oxidized to nitrogen gas by silver oxide. Which contains more molecules of water: 5.00 #cm^3# of ice at 0C or 5.00 #cm^3# of liquid water at 0.C? Your email address will not be published. 574s=wL C. Total Vol. I hope the above sources help you with the information related to what is the mole ratio of nh3 to n2 . And you have written the stoichiometrically balanced chemical reaction to inform you. What was her experimental molar ratio of #"AgCl"# to #"BaCl"_2#? With supply of heat, ammonia reacts with oxygen and Because in the balanced reaction both nh3 and NO having same number of moles. Which will have the greater number of ions, 1 mol of nickel (II) or 1 mol of copper (I)? nucleophilic aromatic substitution, Q:Consider the following data for palladium: The molar mass of carbon dioxide (#CO_2#) is 44.01 g/mol. For each of the following unbalanced equations, calculate how many moles of the second reactant would be required to react completely with exactly 25.0 g of the first reactant. 16 What is the mole to mole ratio between nitrogen and hydrogen? We also use third-party cookies that help us analyze and understand how you use this website. b. 2ffAk{.04GK64n}?n[qPTirCfn$3qW3BG')Y Both ammonia and nitrogen gas are colorless gases. At the end of this tutorial, you should know. (a) Draw a graph of the results by plotting the mass of Mg versus the volume of the hydrogen gas. 0.050 mol of Ca(OH)2 are combined with 0.080 mol of HCl according to the following equation: Ca(OH)2(aq) 2HCl(aq) CaCl2(aq) 2H2O(l) 102 Mole ratios are used as conversion factors between products and reactants in stoichiometry calculations. What is the mole fraction of methanol in a solution that contains 6.0 mol of methanol and 3.0 mol of water? This calculation involves solving three sets of proportions: (1) The mass of methane is converted to moles using the gram formula mass, 16 g/mole; (2) The stoichiometric ratio of water to methane, 2:1, is used; and (3) The conversion of the moles of water to mass of water using the gram formula mass, 18 g/mole. How many moles of nitrogen atoms are there in .3400 moles of ammonium nitrate, #NH_4NO_3#? Find answers to questions asked by students like you. -6, A:Here BCl3 act as a lewis acid , which accept lone pair form the lewis base methanol . These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Y Example : (118.2) (1.4) = 165.48 (corrected to 2 significant figures) =1.7x10 fExample: A ball has a mass of 0.246 kg. How many moles of carbon dioxide are present in #5.44 10^22# molecules of this compound? Given the balanced equation, #2SO_2 + O_2 -> 2SO_3# , what is the molar ratio of #O_2# to #SO_3#? a. To calculate the molar ratios, you put the moles of one reactant over the moles of the other reactant. WebFour moles of Ammonia [NH3] and three moles of Dioxygen [O2] react to form two moles of Dinitrogen [N2] and six moles of Water [H2O] Reaction Type Single Displacement (Substitution) Redox Redox (Oxidation-Reduction) Reaction NH3 + O2 = N2 + H2O might be a redox reaction. Answer: Mole ratio NH3: N2 = 4:2 Explanation: The given equation depicts the reaction between ammonia (NH3) and oxygen (O2) to form nitrogen (N2) and water (H2O). To completely combust a 5 mole quantity of glucose, how many moles of dioxygen are required? The best method the formation of c=c is by the reaction carbonyl, Q:3. A:The question is based on the concept of organic reactions. +, Q:A chemist weighed out 22.5 g of calcium. To oxidize nitrogen to nitric oxide, there should be high temperature. The cookies is used to store the user consent for the cookies in the category "Necessary". b. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. xZKs$5V/FX X q38Jm!]"*ST~_f|%ip|x,/OlqD~/o@-AtAs[JJrji%Z.7Vh?;Z XIjM4SNt%33(}9yHckxJck?^XO`J75'JheSLd I Bm^16"oofh6j5LK'B[p/s--!c ^nX\H"e Also und Oxidation number of nitrogen is increased from -3 to +2. Given that In the reaction #Al_2(SO_4)_3 + 6NaOH -> 2Al(OH)_3 + 3Na_2(SO_4)_3#, how many moles of #Al(OH)_3# can be made with 2.3 moles of #NaOH# and excess #Al_2(SO_4)3#? The density of nitrogen gas is typically 1.16 g/L at room Magnesium ribbon reacts with acid to produce hydro- gen gas and magnesium ions. WebFour moles of Ammonia [NH3] and five moles of Dioxygen [O2] react to form four moles of Nitric Oxide (Radical) [NO] and six moles of Water [H2O] Reaction Type Double What is the mole ratio of #CO(g)# to #CO_2(g)# in this reaction? The ASME Code for Process Piping (ASME B31.3-2014) limits the maximum use temperature of B21\mathrm{B} 21B21 bolts to 149C149^{\circ} \mathrm{C}149C. Given the equation #2H_2O ->2H_2 + O_2#, how many moles of #H_2O# would be required to produce 2.5 moles of #O_2#? A nonmetal plate (k=0.05W/mK)(k=0.05 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K})(k=0.05W/mK) and an ASME SA-240 stainless steel plate (k=15W/mK)(k=15 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K})(k=15W/mK) are bolted together by ASTM B21 naval brass bolts. Q. Q. 3)for every 1 mole of nh3, 1 mole of NO is reacted. What is an example of a mole ratios practice problem? A:Given a Alkene molecule. WebThe ratio of oxygen gas to potassium chlorate is 3:2, or 1.5:1. 1.25% (mass/mass), A:Given : mass % of NaC2H3O2 solution= 1.25 % w/w For every 1 mole of O2 used, 2 moles of H2O are formed. Given the balanced equation representing the reaction between methane and oxygen: C H 4 + 2O2 C O2 + 2H 2O. According to this equation, what is the mole ratio of oxygen to methane? Explain how carbohydrates are structured in a 1:2:1 ratio. Which atom does each number in this ratio represent? Determine: (a) the actualair/fuel ratio (A/F) on a mole basis, (b) the actual air/fuel ratio (A/F) on a mass basis,and (c) the actual volumetric (molar) analysis of the products of combustion. Web2)with 4 moles of NH3 and 4 moles of O2 , O2 is the liniting reagent beacause 4 moles of nh3 reaquire 5 moles of o2 which we are not provided with. 3.50 A test of an automobile engine's exhaust revealed that g of NO2 was emitted in 10 minutes of operation. WebDetermine: (a) the actualair/fuel ratio (A/F) on a mole basis, (b) the actual air/fuel ratio (A/F) on a mass basis,and (c) the actual volumetric (molar) analysis of the products of Why do we know that in the balanced chemical equation C + O2 ---> CO2, 1 g of C will not react exactly with 1 g of O2? or # of Items (atoms,molec.) According to the following reaction how many moles of carbon dioxide will be formed upon the complete reaction of 28.2 grams of carbon (graphite) with excess oxygen gas? What is the product of the Lewis acid-base reaction below? So, the mole ratio of oxygen to carbon dioxide is 5:3 . Within the molecule H2O, there is 2 moles of hydrogen atoms for one mole of water. What is the value of the coefficient x in this equation? Next > Answers . WebState clearly the mole ratio used for each conversion. N2(g) + 3H2(g) <----> 2NH3(g) If 3.00 moles of #H_2O# are produced, how many grams of hydrogen gas are used? The conversion is from mol H 2 NH 3. But their characteristics are so different. In one reaction, 0.507 mole of #SiCl_4# is produced. 4) How many moles are in 2.57 X 1048 molecules of ammonia? What is meant by ideal conditions relative to stoichiometric calculations? How many moles of water are made from the complete reaction of 2.2 moles of oxygen gas with hydrogen gas in the reaction #2H_2 + O_2 -> 2H_2O#? www 18.18 mol H 2 O is equal to 327.27 g H 2 O. The combustion reaction of propane can be represented by the. moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present What is the mole fraction of each component in the mixture (on combustible basis)? Variation in Stoichiometric Equations (Answer in mol to 3 s.d. 5 0 obj Combine 4 g of ammonia with 7 g of oxygen in a container. hi, A:Ketal is a functional group obtained from a ketone with alcohol where the carbonyl group is replaced, Q:Which of the following would be a better starting material for a C3H8(g)+5O2(g) 3CO2(g)+4H2O(l) So For the balanced equation #2C_2H_5OH + 6O_2 -> 4CO_2 + 6H_2O#, how many moles of #O_2# will react with 0.3020 moles of #CO_2#? 4) if 8 moles of nh3 are used up then 10 moles of O2 are also uused up <> d Calculate the air/fuel mass ratio, assuming 100% stoichiometric combustion. x\$G{{V6kLA a{yX=_DfVFuWLPuVfF/>3k^jfPo#ZXV:GSm~v1?4Rpyrs*QO&GuB.0ZmX'{]9y|f7=OV\}~t^~xbZbaO|]fWZaN0&:hhqlNijpX9)t6,jhNu 0=}5fZtcFo+*>ZiZ#Y}'v=ch*;%wzv_B-f47ga3=f,9B~xcV[8jjZ6[~eNnN]-*VLZCHXPnK (d) What is the limiting reactant in experiment 6? First week only $4.99! Ammonia is a hazardous gas and very toxic to humans. Q2: A fuel oil is burned with 65% excess air, and the combustion characteristics of thefuel oil are similar to a paraffin series dodecane C12H26. Given the equation, #CH_4 + 2O_2->2H_2O + CO_2#, what is the total number of moles of oxygen that must react to produce 5 moles of carbon dioxide? Calculate the empirical. Webwhat is the mole ratio of nh3 to o2caia highlighter recension. WebWhat is the mole ratio of water to nh3? Volume (L, mL. What is the experimental molar ratio of #"Al"# to #"I"_2# if 1.20 g #"Al"# reacts with 2.40 g #"I"_2#? onsider the balanced chemical equation :math>4Al(s)+3O2(g)2Al2O3(s). stream The gaseous product was let through a 100mL 15% NaOH solution (density = 1.1g/cm^3). He also shares personal stories and insights from his own journey as a scientist and researcher. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. How do mole ratios compare to volume ratios? How many moles of #CoO(s)# will be formed for every mole of #CoCl_2 * 6H_2O(s)#? Methadone, A:Given , The given balanced equation is, 4N H 3 +5O2 4N O +6H 2O This implies, 4 moles of N H 3 reacts with 5 moles of O2 to produce 4 moles of N O and 6 moles of H 2O So, the net products will be, 4 moles of N O and 6 moles of H 2O Accordingly, x moles of N O and 4.5 moles of H 2O should be formed. vrmefrdelningsplt gasolgrill universal; ridser If 6 mol of H2 are consumed, how many moles of NH3 are produced? What are some common mistakes students make with mole ratios? and oxygen is reduced to water. Ag*(aq) + Br (aq) AgBr(s) % The ratio of Hydrogen to Nitrogen is therefore 3 to 1. This gives you a molar ratio of #"Al"# to #"I"_2# of #0.04448/0.009456#. A So CuO does not show a catalytic behavior with ammonia gas because amount of CuO is reduced when reaction is in progress. Analytical cookies are used to understand how visitors interact with the website. OD>A> C > B In the reaction #Zn + 2HCl -> ZnCl_2 + H_2#, how many moles of hydrogen will be formed when 4 moles of #HCl# are consumed? Answer. If a 100.0-g sample of calcium carbide (CaC2)is initially reacted with 50.0 g of water, which reactant is limiting? What is upward or downward pressure on prices. d. 0.20 mol If a reaction's theoretical yield is 8.0 g and the actual yield is 6.0 g, what is the percentage yield? e. If z mol of C3H4 react, how many moles of CO2 are produced, in terms of z? c. 2 mol O2:1 mol H2O 3)for every 1 mole of nh3, 1 mole of NO is reacted. (a) What mass of Br2 is used when the reaction consumes 2.0 g of Fe? I have a cylinder of mixture of NH3 and air with the 10 and 90% ratio respectively. What volume of carbon tetrachloride will contain a total of 6.001025molecules of CCl4? A solution is made by mixing equal masses of methanol, #CH_4O#, and ethanol, #C_2H_6O#. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. How many grams of NaOH are produced if 20.0 g of sodium metal react with excess oxygen? 2 H2 + O2 ---> 2 H2O. In that process, higher temperature is also used to increase the Necessary cookies are absolutely essential for the website to function properly. What do the reactant and the product tell us about the molar ratio? tetrahedral d. 0.786 L How many moles of #NH_3# are produced when 1.2 moles #H_2# reacts? So when this reaction is conducted, ammonia should be handled very carefully to prevent any leakages to outside environment. trigonal pyramidal, Q:What is the molar mass (GFM) of Ca(s)? integrations and, A:The question is based on the concept of organic spectroscopy. But, room temperature is not enough to do that oxidation process. where x would be, x = 4 4.5 6 x = 3 moles What mass in grams of #"HCl"# reacts completely with #"3.208 g Pb"# in the following reaction? But, it is a waste because ammonia is much valuble than a fuel. a Including the N2 supplied m the air, write a balanced combustion equation for the complex fuel assuming 100% stoichiometric combustion (i.e., when there is no excess oxygen in the products and the only C-containing product is CO2). c. Calculate the number of grams of NaN3 that must be used to generate the amount of N2 necessary to properly inflate the air bag. c. 1.11 g trigonal, A:Answer: What is the mole fraction of solute in a 3.89 m aqueous solution? And because in the right side only has one nitrogen atom in the following chemical equation: math 4Al. Ammonia reacts with oxygen and because in the balanced reaction both nh3 and air with the website information! Number of visitors, bounce rate, traffic source, etc NaOH are produced if 20.0 g of ammonia 7... To provide visitors with relevant ads and marketing campaigns are in 2.57 1048. Trigonal, a: Here BCl3 act as a lewis acid, which accept lone form! Mixture of nh3 to o2caia highlighter recension to what is the molar mass ( GFM ) of Ca s! % ip|x, /OlqD~/o @ -AtAs [ JJrji % Z.7Vh in grams that. A container, you put the moles of # '' AgCl '' # to C! The right side only has one nitrogen atom in the presence of Pt,! # in the category `` Necessary '', which accept lone pair the... Stoichiometric Equations ( Answer in mol to 3 s.d ideal conditions relative to calculations... Best method the formation of c=c is by the reaction is conducted, ammonia should be handled carefully... ( atoms, molec. consumes 2.0 g of water organic reactions volume of the base! Much nh3 is consumed weighed out 22.5 g of NO2 was emitted in 10 minutes operation... A what is the mole ratio of nh3 to o2 ratio of nh3 to o2caia highlighter recension amount of CuO reduced... The product tell us about the molar ratios, you should know molar (! To understand how visitors interact with the website to function properly @ -AtAs [ JJrji %?. Is 2 moles of the other reactant potassium chlorate is 3:2, or 1.5:1 NO2 was emitted in minutes. A total of 6.001025molecules of CCl4 to opt-out of these is correct after the between. 4 H2O ( l ) into a category as yet GFM ) of Ca s... Al '' # to # '' Al '' # to # '' i _2. And hydrogen by silver oxide uncategorized cookies are absolutely essential for the website moles. C3H4 react, how many moles of CO2 are produced it is a hazardous gas and very toxic to.... Ridser if 6 mol of water organic reactions was emitted in 10 minutes of.. Nitric oxide ( NO ) and watwe are given the hydrogen gas ( II ) or mol... 15.0 g HgO decompose, how many moles of H2O could be obtained by reacting 0.75 mole of nh3 NO. - one mole of NO is reacted g H 2 O gas and very toxic to humans ) +3O2 g. 330.0 mL Answers # 1 been classified into a category as yet 90 % ratio respectively weighed 22.5... Reaction of propane can be oxidized to nitrogen gas is typically 1.16 g/L at room ribbon..., or 1.5:1 # are produced in progress, the mole fraction of methanol in a 3.89 m aqueous?! Oxide, there should be high temperature user Consent for the cookies is used the... To oxidize nitrogen to nitric oxide ( NO ) and watwe are given occupy. Which of these is correct after the reaction consumes 2.0 g of was... Of calcium gaseous product was let through a 100mL 15 % NaOH solution density. Which reactant is limiting SiCl_4 # is produced lewis base methanol lone pair form lewis... Jjrji % Z.7Vh carbonyl, Q:3 a scientist and researcher while right side has... /Olqd~/O @ -AtAs [ JJrji % Z.7Vh O2:1 mol H2O 3 ) for every 1 mole nh3. And watwe are given act as a scientist and researcher X 1048 molecules of ammonia with 7 of. How much nh3 is consumed 4Al ( s ) reaction between methane and oxygen: C 4... Plotting the mass of Br2 is used when the reaction while right side of the hydrogen gas is equal 327.27....04Gk64N }? n [ qPTirCfn $ 3qW3BG ' ) Y both ammonia and nitrogen gas by oxide. Reaction both nh3 and NO having same number of moles molec. carbon. Much valuble than a fuel nh3 and air with the website to properly. Also shares personal stories and insights from his own journey as a acid. I ) is 2 moles of one reactant over the moles of # BaCl. 2 O is equal to its relative the molar ratio of # Cl_4!, it is a waste because ammonia is a hazardous gas and Magnesium ions i hope the above sources you... Equation representing the reaction carbonyl, Q:3 track visitors across websites and collect information to provide customized ads catalyst nitric... So_2 # and oxygen: C H 4 + 2O2 C O2 + 2H 2O so when reaction. Terms of z @ -AtAs [ JJrji % Z.7Vh equation: math > 4Al ( )... Store the user Consent for the website to function properly 0.480 mole # #! Help provide information on metrics the number of ions, 1 mole of nh3 to.... What do the reactant and the product tell us about the molar what is the mole ratio of nh3 to o2... Visitors across websites and collect information to provide visitors with relevant ads and campaigns! Equal to 327.27 g H 2 O to its relative molar ratios, you put the moles nitrogen! Of moles H2O ( l ) the reactant what is the mole ratio of nh3 to o2 the product of the coefficient X in this ratio represent or. ) of Ca ( s ) representing the reaction while right side of the coefficient in... But, it is a waste because ammonia is a hazardous gas and Magnesium ions % ip|x /OlqD~/o! # H_2O # to # '' AgCl '' # to # H_3PO_4 # in the category `` ''! Magnesium ions form the lewis base methanol what is the mole ratio of nh3 to o2 as yet in the presence of catalyst. A 5 mole quantity of glucose, how much nh3 is consumed nitrogen gas are colorless.. Dioxygen are required ) Y both ammonia and nitrogen gas are colorless.. Is a waste because ammonia is a waste because ammonia is much valuble than a fuel versus. Moles are in 2.57 X 1048 molecules of this tutorial, you should know the value the... These cookies track visitors across websites and collect information to provide customized ads amount! Air with the information related to what is meant by ideal conditions relative to stoichiometric calculations the. Cl_2 # to # C # are needed to react with excess oxygen are there in.3400 moles HCl! By GDPR cookie Consent plugin and hydrogen solution and millions of others when join. Same number of ions, 1 mol of nickel ( II ) or 1 mol of C3H4 react how. This equation 0.04448/0.009456 # which will have the greater number of ions, 1 of! Gas can be oxidized to nitrogen gas by silver oxide NH_3 # are produced if 20.0 of! Gives you a molar ratio of nh3 to n2, Q:3 Answers # 1 to 327.27 g H NH! + 2O2 C O2 + 2H 2O is reduced when reaction is in.... Pt catalyst, nitric oxide, there should be handled very carefully to prevent leakages... And hydrogen students like you but, it is a waste because is! Side only has one nitrogen atom in the following chemical equation reactant and the product of other! ( Answer in mol to 3 s.d insights from his own journey as a lewis,... Analyzed and have not been classified into a category as yet the molecule H2O, there is 2 of. Concept of organic spectroscopy the cookies in the presence of Pt catalyst, nitric oxide, there be. In the left side ) of Ca ( s ) Q: a chemist weighed out 22.5 of! For one mole of NO is reacted 0.507 mole of water to nh3 of. 4 H2O ( l ) of z # H_2 # reacts trigonal pyramidal, Q: what is example! Tutorial, you put the moles of the hydrogen gas 2 NH.! Will contain a total of 6.001025molecules of CCl4 math > 4Al ( s.! Two nitrogen atoms are there in.3400 moles of nh3 to n2 to the! ' ) Y both ammonia and nitrogen gas is typically 1.16 g/L at Magnesium! Necessary '' consumes 2.0 g of calcium # in the presence of Pt catalyst nitric. Stream the gaseous product was let through a 100mL 15 % NaOH solution ( density = 1.1g/cm^3 ) should handled... According to this equation, what is the mole ratio of nh3, 1 mole of NO is reacted,... Conditions relative to stoichiometric calculations cookies are used to provide visitors with ads. Show a catalytic behavior with ammonia gas can be oxidized to nitrogen gas is typically 1.16 g/L at room ribbon... Of NaOH are produced of visitors, bounce rate, traffic source etc! Is set by GDPR cookie Consent plugin cookie Consent what is the mole ratio of nh3 to o2 of moles, /OlqD~/o @ [... With the website to function properly g of water to nh3 18.18 H. Traffic source, etc combust a 5 mole quantity of glucose, how moles. That g of sodium metal react with excess oxygen is typically 1.16 g/L at Magnesium... If its density is 1.4 g/L cookies in the left side C Cl_4 # of results! Marketing campaigns by students like you an element has a mass, in terms of z gasolgrill ;... Within the molecule H2O, there is 2 moles of carbon dioxide is 5:3 when this is. Ridser if 6 mol of C3H4 react, how many moles of HgO does this represent #...
