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# Reaction Stoichiometry

Reaction Stoichiometry refers to the examination of the relative abundances of reactants and products in a chemical reaction within a defined system. In order to use reaction stoichiometry to calculate desired quantitative data, it is important to first understand the relationships between the reactants and the products. This requires the process of balancing reactions, which is usually the most important step when doing stoichiometric calculations.

To balance an equation, it is necessary that there are the same number of atoms in the reactants as there are in the products. One can do this by raising the coefficients of individual reactants or products.

For example, the combustion of methane involves reacting methane (CH4) and oxygen (O2) to form carbon dioxide (CO2) and water (H2O). The unbalanced chemical equation can be written as:

CH4(g) + O2(g) --> CO2(g) + H2O(l)

It can be seen that the number of atoms on each side are unbalanced; and so raising the coefficients of O2 and H2O to 2 will balance the equation for the combustion reaction:

CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)

Thus, from these stoichiometric coefficients, it can be seen that 1 mole of methane reacts with 2 moles of molecular oxygen to form 1 mole of carbon dioxide and 2 moles of water. Using these relative ratios, one can hypothetically say that 0.1 moles of methane requires 0.2 moles of oxygen or 0.6 moles of methane requires 1.2 moles of oxygen. Therefore, understanding the relationship between reactants and products is absolutely fundamental to run stoichiometric calculations on chemical reactions.

### Balancing and stoichiometry questions

1. For the equation, Al + O^2 Al^2O^3 answer the following questions: a. Balance the above equation. b. If 10.0 g of Al are used, how many g of oxygen are needed and how many g of product are produced? ?c. If you had 20 moles of Al, how many moles of oxygen would be needed and how many moles of product would be produced?

### Magnesium Stoichiometry

Magnesium can be used as a "getter" in evacuated enclosures, to react with the last traces of oxygen. (The magnesium is usually heated by passing an electric current through a wire or ribbon of the metal.) If an enclosure of 0.384 L has a partial pressure of O2 of 3.6×10&#8722;6 torr at 28 C degrees, what mass of magnesium

### Energy, q, w, Enthalpy, and Stoichiometry II and Specific Heat

Problem 1 - Energy, q, w, Enthalpy, and Stoichiometry Consider the following reaction: 2Mg(s)+O2(g)>>2MgO(s)&#916;H = -1204kJ 1) Is this reaction exothermic or endothermic? 2) Calculate the amount of heat transferred when 2.1 g of Mg(s) reacts at constant pressure. Express your answer using two significant figures.

### Chemistry Stoichiometry - Limiting Reactants

The fizz produced when an Alka-Seltzer® tablet is dissolved in water is due to the reaction between sodium bicarbonate (NaHCO3) and citric acid (H3C6H5O7): 3NaHCO3(aq)+H3C6H5O7(aq)>>3CO2(g)+3H2O(l)+Na3C6H5O7(aq) In a certain experiment 1.05g of sodium bicarbonate and 1.05g of citric acid are allowed to react. - Which is

### Theoretical and percentage yield

When benzene (C6H6) reacts with bromine (Br2), bromobenzene (C6H5Br) is obtained: C6H6+Br2>>C6H6Br+HBr - what is the theoretical yield of bromobenzene in this reaction when 27.0 g of benzene reacts with 58.5 g of bromine? - if the actual yeild of bromobenzene was 49.9g, what was the percentage yield?

### Stoichiometry: How Many Grams of Zinc Oxide Are Formed

When zinc sulfide is heated in air, zinc oxide and sulfur dioxide forms: 2ZnS(s) + 3O2(g) = 2ZnO(s) + 2SO2(g) How many grams of zinc oxide is formed when 100 grams of zinc sulfide is burned? Assume that the zinc sulfide is the limiting reactant. The answer is one of the following: a. 8.5 grams ZnO b. 23.5 grams ZnO c. 4

### Stoichiometry in Reactions of Aluminum and Sodium Hydroxide

6) Explain why the reaction of 31.1636 g of aluminum metal (atomic mass 26.9815 g/mol) with 110.00 g of sodium iodate (molar mass 197.89 g/mol) in the presence of nitric acid produces the equivalence of only 25.00 g of aluminum ions; whereas,reaction with 120.00 g of sodium iodate produces the equivalence of 31.1636 g of aluminu

### Titration problems

In the reaction CaCO3 + 2HNO3 &#8594; Ca(NO3)2 + CO2 + H2O, how many milliliters of 0.1015 M HNO3 are required to react with 0.9857 grams of CaCO3? Find the fraction of association of a 0.120 molar solution of hydrogen cyanate. Ka for hydrogen cyanate = 3.30×10-4. A sample containing 0.2784 grams of sodium chloride

### Chemical Engineering: Stoichiometry and Mass Balance

Please see the attached file for the fully formatted problems. Just do A3 and A4, please. A3. Solid calcium fluoride (CaF2) reacts with sulphuric acid to form solid calcium sulphate (CaSO4) and gaseous hydrogen fluoride (HF). The HF is then dissolved in water to form hydrofluoric acid. A source of calcium fluoride is fluorite

### Stoichiometry of calcium chloride and sodium phosphate

Calcium chloride and sodium phosphate react to form solid calcium phosphate in the following reaction: 3CaCl2 + 2Na3PO4 = Ca3(PO4)2 + 6NaCl What mass of sodium phosphate is required to react completely with 9.75 grams of calcium chloride?

### Calculating Moles and Mass: Example Problem

Several brands of antacids use Al(OH)3 to react with stomach acid, which contains primarily HCl: alpha Al(OH)3(s) + beta HCl(aq) = gamma AlCl3(aq) + delta H2O(l) Balance the equation. Calculate the number of grams of HCL that can react with 0.560g of Al(OH)3. Calculate the number of grams of AlCl3 formed when 0.560

### glucose produced by small patch of trees

Burning of fossil fuel (equation a), gasoline, produces carbon dioxide CO2;, one of the global warming contributors. But carbon dioxide plays an important role in photosynthesis which reacts with water in the presence of sunlight and produces glucose and oxygen gas according to the equation below (equation b). Excessive loggin

### Na3PO4 + HCl: Concentration/Stoichiometry Problem

Sodium phosphate, Na3PO4, reacts with HCl to form H3PO4 and NaCl. If 0.1 mole of sodium phosphate is completely converted to H3PO4 in 500 mL of solution what will be the concentration of the H3PO4 solution?

### Stoichiometry of an Acid-Base Reaction

Procedures: 1. Take a beaker from the Glassware shelf and place it on the workbench. ***mass of empty beaker is 47.420g*** 2. Take a balance from the Tools shelf and drop it directly onto the beaker. Record the mass of the empty beaker. 3. 0.5g of Na₂CO₃ to the beaker. Record the mass of the beaker plus Na₂CO₃. R

### Calculating amount of alkali to change pH

Problem: I have a 17,000 gallon tank of water and a weak acid (acetic acid to be specific); the tank has a pH of 4.4. Using an alkali such as Na2CO3 (sodium carbonate) --- how much Na2CO3 is needed to raise the pH of this 17000 gallon tank from pH 4.4 to pH 4.8? Please help and help me understand computations. Thank yo

### 12 Problems: Stoichiometry, Yield and Substance Remaining

Calculate how many moles of each product would be complete conversion of 1.25 mol of the reactant indicated in boldface, what is the mole ratio used. C2H3OH (I) + 302(g) &#61664; 2CO2(g) + 3H2O(g) N2(g) + O2(g) &#61664; 2NO(g) 2NaClO2(s) + Cl2(g) &#61664; 2ClO2(g) + 2NaCl(s) 3H2(g) + N2(g) &#61664; 2NH3(g) Calculate the m

### Balanced equations for the various steps in synthesizing lidocaine

The reduction of 1,3-dimethyl-2-nitrobenzene to 2,6-dimethylaniline involves two steps. I am having difficulty balancing the equations, and I have no idea of the mechanism involved. Ar(CH3)2 + SnCl2.2H2O +HCl --> Ar(CH3)2(+)Cl(-) + SnCl4 (step 1) Ar(CH3)2(+)Cl(-) + KOH --> Ar(CH3)2NH2 (step 2) I could also use help with the

### Ascorbic Acid: Acidity, Titration, and Ionic Concentrations

1. Calculate the molarity of the ascorbic acid solution: (a) Mass of ascorbic acid used: 0.1 (b) Moles of ascorbic acid (MW=176.1 g/mol): not sure (0.000568g/moL) (c) Volume of solution (mL): 100.01mL (d) Ascorbic acid concentration (mol/L): 2. For each titration, record and calculate the following:

### Stoichiometry Problem Involving Ozone: Detailed Mole/Mass Solution

Ultraviolet light in the stratosphere can split chlorine atoms from Freon molecules. Once formed, the free chlorine atoms can react with and destroy the ozone. One of the reactions involved is represented here. Cl + O3 -----> ClO + O2 For every 1000 g of ozone, how many grams of O2 are formed during this reaction?

### Excess of Acetic Anhydride

What do they mean by using 55.0% excess of acetic anhydride?

### Heat in Reactions

[show your work and note what formulas you used] A mercury mirror forms inside a test tube by the thermal decomposition of mercury(II) oxide. 2 HgO(s) 2 Hg(l) + O2(g) Hrxn = 181.6 kJ 1. How much heat is needed to decompose 505 g of the oxide? 2. If 270. kJ of heat is absorbed, how many grams of mercury form?

### General Chemistry Problems: Nickel and Silver Nitrate

7. Nickel replaces silver from silver nitrate in solution according to the following equation: 2AgNO3 + Ni (arrow) 2Ag +Ni(NO3)2 a. If you have 22.9 g of Ni and 112 f of AgNO3, which reactant is in excess? b. What mass of nickel(II) nitrate would be produced given the quantities above? 15. Sulfu

### Balance Equations and Mass Percent

Problem: Iodine is present in Chilean saltpeter as iodate anion (IO3-). The amount of iodate anion in a particular sample may be determined by dissolving the sample and then reacting the IO3-(aq) with excess aqueous sodium bisulfite (NaHSO3(aq)) via: 2 IO3-(aq) + NaHSO3 (aq) -----> I2(aq) + Na+(aq) + 5SO4-2(aq) + H+(aq) + H2O(l)

### Limiting reactant

Dinitrogen pentoxide gas reacts with water to produce aqueous nitric acid. If 54.1mL of water react with 600 g of dinitrogen pentoxide, how many grams of nitric acid will be produced? Assume water has a density of 1.00g/mL.

### Dinitrogen Pentoxide Gas Reacts with Water

Dinitrogen pentoxide gas reacts with water to produce aqueous nitric acid. If 54.1mL of water react with 600 g of dinitrogen pentoxide, how many grams of nitric acid will be produced? Assume water has a density of 1.00g/mL. [Remember to use the correct number of significant figures and write the answer in scientific notation]

### Stoichiometry for Isotonic Solutions

A solution of KI in water is .25M. How much water must be added to 50mL of this solution to reduce the concentration to .10M? assume volumes are additive.----2. An isotonic saline is .89% NaCl (w/v). Suppose you wanted to make a liter of isotonic solution of NH4Cl. What weight of NH4Cl would you need? please provide step by s

### Mole Consumption

In equation: N2+3H2 > 2NH3, how many moles of hydrogen are required to produce 556g ammonia?

### Stoichiometry and the Kroll Process

Zirconium is obtained industrially using the Kroll process. The Kroll process is a pyrometallurgical process used initialy to produce titanium and later developed to produce zirconium. It is a high temperature process that combines zirconium (IV) chloride with magnesium metal to produce zirconium metal and magnesium chloride via

### Stoichiometry and Multiplying Electrons

Complete and balance the following reaction: As(s)+ClO3^-(aq) (right arrow) H3AsO3(aq)+HCLO (aq) I have the following options: -split into 1/2 reactions -balance all but H and O -balance O by adding H20 -balance H+ by adding protons -balance charge by adding electrons I am stuck, after adding equations to get electro

### Stoichiometry/balancing redox reactions

I need help on how to balance redox reactions in a systematic way. I already have the answers, I need to know step-by-step how to get there...thanks! Example: cCmplete and balance the following reaction: H2O2+Cl2O7 (right arrow) Clo2^- +O2 (which occurs in basic solution) Also - how do you tell what was oxidized and what wa