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# Stoichiometry

### Molality of a Final Solution and Electron Configuration

1. What is the molality of the final solution when 10.0g of sucrose(C12H22O11) is dissolved in water to form 1.50kg of solution? Use 3 sig figs 2. What is the chemical formula of titanium(IV) chloride? 3. How man grams of K2SO4 are contained in 200ml of a 0.100M K2SO4 solution? Use 3 sig figs 4. Write the electron confi

### What is the weight percentage of C in C6H12O6?

1. What is the weight percentage of C in C6H12O6? Use sig figs 2. What is the molar mass of TiCl4? 3. What is the molarity of a 1.30 L solution containing 6.00g of NaCN? Use sig figs 4. Write a balanced chemical equation for the combustion of octane, C8H18 5. 20.0g each of Fe2O3 and Al are mixed together and react according

### Calculations of MW and observed rotation

1.The hormone insulin contains 3.4% sulfur. What is the minimum molecular weight of insulin? The actual molecular weight is 5734; how many sulfur atoms are probably present per molecule? (Please explain reasoning clearly). 2. The specific [alpha] of (-)-morphine is -132 degrees. What will the be the observed rotation w

### Stoichiometry Example Problems

1. Calculate the emperical formula for a chemical compound which gives the following analysis 12.6 percent lithium 29.2 percent sulfur and 58.2 percent oxygen? 2. The action of bacteria on meat and fish produces a poisonous compound called cadaverine. It is 58.77 percent carbon, 13.81 percent hydrogen, 27.40 percent nitrogen.

### Composition by mass of NaNO3 mixed with Mg(NO3)2

A solid consists of a mixture of NaNO3 and Mg(NO3)2. When 6.75 g of the solid is dissolved in 50.0 g water, the freezing point is lowered by 5.35°C. What is the composition, by mass, of the solid? Mg(NO3)2 g NaNO3 g

### Osmotic Pressure moles NaCl exist as ion pairs

An aqueous solution is 1.00% NaCl by mass and has a density of 1.071 g/cm3 at 25°C. The observed osmotic pressure of this solution is 7.83 atm at 25°C. (a) What fraction of the moles of NaCl in this solution exist as ion pairs? % (b) Calculate the freezing point that would be observed for this solution. °C

### Homework help...Calculating the gram-formula-weight...and more: step by step would be greatly appreciated.

Calculate the gram-formula-weight: Ca(OH)2: AlF3: Na2SO4: I also need help with answering the following problems using this equation: CH4+2O2-->CO2+2H2O 1. How many liters of CO2 would be produced if 32 grams of CH4 are combined with oxygen? 2. How many grams of H2O would be produced when the 32 grams of

### Analysis of Hydrogen Peroxide Solutions

Molarity of KMnO4: .2 M Volume of H2O2: 10 mL Titration of KMnO4 and new H2O2 Trial 1(Rough) Trial 2(Fine) Trial 3(Fine) Initial volume 12.00mL 12.00mL 12.00mL Final volume 13.98mL 12.10mL 12.05mL Titration of KMnO4 and old H2O2 (Fine Ti

### Tempurature Dependence of Salt Solubility. Calculations Help

I don’t understand how to make this graph...what is it supposed to look like? I’ve tried and just can’t make my computer work it...I also don’t understand what my experimental mass and official masses are supposed to be... please help! Data: List all measurements and include proper labels. Test tube Crystallizing Tempe

### Gases and Volumes at STP

Hey. I am unsure of how to answer this question: Many gases are shipped on high-pressure containers. Consider a steel tank whose volume is 65.0 L and which contains 02 gas at a pressure of 16 500 kPa at 23 * C. a) What mass of O2 does the tank contain? b) What volume would the gas occupy at STP? c) At what temperature

### Calculations of Empirical Formula for Unknown Compound

Combustion analysis of 1.0g of an unknown compound was found to give the following data: 2.97 g CO2 and 0.73 g of H2O. Dtermine the empirical and molecular formula for the unknown compound. So far, I took: 2.97/44.01 = .067 moles of CO2 0.73/18.01 = .0405 moles of H2O then I took 2.97 + 0.73 g to = 3.7g - 1 g of unkn

### Colligative properties of solutions

How is reverse osmosis related to the colligative properties of solutions? What are other colligative properties? How are they similar or different? What common factors are present in equations for colligative properties? Why do you think any given factors are associated with a particular colligative property?

### Calculations of Steam Distillation

A natural product (MW = 150) distills with steam at a boiling temperature of 99 ( degrees Celsius) at atmospheric pressure. The vapor pressure of water at 99 (degrees Celsius) is 733 mmHG. 1. Calculate the weight of natural product that codstills with each gram of water at 99 (degrees Celsius)? 2. How much water must be re

### Important information about Molecular and empirical formulas

When asked to find examples of three (non-ionic) compounds whose molecular and empirical formulas are the same and three that are different why are ionic compounds excluded?

### Determining Grams of Carbon Dioxide Formed: Example Problem

Amyl alcohol can burn in oxygen to produce carbon dioxide and water. If amyl alcohol is C5H11OH and oxygen a diatomic gas O2, write and balance the combustion equation and answer the following: If 5 grams of amyl alcohol is burned, how many grams of carbon dioxide are formed?

### Determining Grams of Metallic Copper Produced: Example Problem

An impure sample of copper sulfate weighing 5.52 grams was dissolved in water and allowed to react with excess zinc. Given CuSO4(aq) + Zn(s) = ZnSO4 (aq) + Cu(s), what is the percent CuSO4 in the sample if 1.49 grams of metallic copper was produced? Please explain the process.

### How much silver chloride will precipitate

What mass of solid silver chloride will precipitate from a solution containing 1.5 grams of calcium chloride if an excess amount of silver nitrate is added? CaCl2(aq) + 2AgNO3(aq) = 2AgCl(s) + Ca(NO3)2 (aq) Please explain how this question is done.

### Identifying the correct metal

A sample of metallic element X, combines completely with oxygen gas (O2) forming a metal oxide of formula XO. If the amount of oxygen gas used is 32 grams, and the total amount of metallic oxide formed is 112 grams, Determine the identity of the metal. The choice is one of the following: 1. sodium 2. magnesium 3. calcium

### Vapor pressure mass percentage of nitrogen in compund

The nitrogen content of organic compounds can be determined by the Dumas method. The compound in question is first reacted by passage over hot CuO Compound N2(g) + CO2(g) + H2O(g) The product gas is then passed through a concentrated solution of KOH to remove the CO2. After passage through the KOH solution, the gas

### Determining Empirical and Molecular Formula: Example Problem

A compound contains only C, H, and N. It is 58.51% C and 7.37% H by mass. Helium effuses through a porous frit 6.40 times as fast as the compound does. Determine the empirical and molecular formulas of this compound.

### Molecular formula of Nitrogen and Hydrogen molecule

A compound contains only nitrogen and hydrogen and is 87.4% nitrogen by mass. A gaseous sample of the compound has a density of 0.977 g/L at 710. torr and 99.9°C. What is the molecular formula of the compound?

### Volume, pressure, acetylene gas reacting with solid calcium carb

Acetylene gas, C2H2(g), can be produced by reacting solid calcium carbide, CaC2, with water. The products are acetylene and calcium hydroxide. What volume of wet acetylene is collected at 25°C and 725 torr when 4.10 g calcium carbide is reacted with an excess of water? (At 25°C the vapor pressure of water is 23.8 torr.)

### Determine the identity of an unknown metal

An atom of an unknown metallic element X combines with a fluorine atom in a 1 to 1 ratio. Fluorine gas is a diatomic molecule (F2) and has a density of 1.6 grams/liter. If exactly 132.9 grams of the metal X combines with 11.88 liters of fluorine gas, determine the identity of the unknown metal X. Hint: For every atom of fluo

### Determine the composition of a solder alloy

Electronic solder is an alloy of tin and lead. Determine the composition of this solder alloy. Answer in % lead (by mass). Here is the data: Density of pure lead: 11.4 g/cm^3 Density of pure tin: 7.31 g/cm^3 Density of solder sample: 10.35 g/cm^3 Remember find the % lead by MASS. 1. 65.98 % lead by mass 2. 74.32 % lead

### The Composition of Gold

You have a piece of gold jewelry weighing 8.5 grams. Its volume is 0.64 cubic centimeters. Assume that th metal is an alloy of gold and copper, which have densities of 19.3 g/cm^3 and 8.5 g/cm^3 respectively. Also assume that there are no changes in volume when the metals are mixed. First, calculate the percentage of gold by vol

### Evolved Gas

Lithium metal reacts with water to yield hydrogen gas. A piece of lithium weighing 10.63 grams was added to 27.57 grams of water. When finished, the solution - containing lithium hydroxide - weighed 34.85 grams. How many grams of hydrogen gas was evolved? a. 3.35 grams b. 21.2 grams c. 1.53 grams d. 1.05 grams e. 4.766 gr

### Increase the average carbon dioxide level in the atmosphere

Taking the mass of the atmosphere to be 5.8E15 metric tons, what mass of carbon must be burned in order to increase the average carbon dioxide level in the atmosphere by 200ppm by volume (in metric tons)? The average molar mass of air is 28.96 g/mol.

### An analysis of a wet sludge sample on a ppm weight basis indicates a value of 2900 ppm. The sample has a dry solids content of 19% (by weight) or a moisture content of 81% (by weight).

An analysis of a wet sludge sample on a ppm weight basis indicates a value of 2900 ppm. The sample has a dry solids content of 19% (by weight) or a moisture content of 81% (by weight). I have seen numerous computations including: ppm dry = ppm wet/% solids or, ppm dry = ppm wet/% moisture content Which is correct....

### Limestone and Sulfur

Assume that the wet limestone process requires 1 metric ton of calcium carbonate to remove + 85.0 % of the sulfur from 4 metric tons of coal containing + 10.0 % S Assume that the sulfur product is calcium sulfate. Calculate the percentage of the limestone converted to calcium sulfate.

### Photosynthesis and fixed carbon

Please provide detailed steps. a) Photosynthesis is estimated to produce 350.0 g (dry weight) of plant matter per square meter, 50% of which is carbon. Calculate the total number of grams of carbon "fixed" each year by 1000 square meters. b) The photosynthetic reaction can be represented as: 6CO2 + 6H2O -> C6H12O6 + 6O2 Of