Share
Explore BrainMass

Stoichiometry

Molar concentration, solutes, and solvents

Calculate the molar concentration of a solution containing 4.75 of Ca(NO)3 in 0.200 L Calculate the volume of 2.00M Na3(PO)4 in milliliters that contains 6.80g of solute. How many grams of solute are present in 42.0mL of 0.200M K2Cr2O7 ? If 4.20g of (NH4)2SO4 is dissolved in enough water to form 400mL of solution

Find the concentration of the hydrogen peroxide solution.

Please see attached file for full problem description. 1. Find the concentration of the hydrogen peroxide solution. Doing an analysis of hydrogen peroxide using Potassium Permangate Equation is: 2KMnO4(aq)+5H2O2(aq)+3H2SO4(aq) -->5O(g)+K2SO4(aq)+2MnSO4(aq)+8H2O(l) Potassium Permangate is the titrant. Obtained a 1.00mL al

Example of Lab Report: Decomposition of Potassium Chlorate

Calculate and record the following for the experiment performed with 10.000 g KClO3 1. (a) mass of the crucible with manganese(IV) dioxide (in grams) = 53.300g (b) mass of the crucible after potassium chlorate has been added (in grams) = 63.300g (c) mass of the crucible after heating (in grams) = 59.383g (d) mass of po

Finding the Age of a Rock Using Radioactive Decay Data

(1) The half life of U-238 is 4.51x10^9 yrs. In a rock containing N atoms of U-238, how many Helium atoms are produced by radioactive decay of U-238 to Pb-206 in 4.51x10^9 yrs? (2) A rock is analyzed for its helium and uranium content and found to contain 1.00x10^-9 mole of U-238 atoms, and 2.00x10^-9 mole of Helium atoms. As

Concentration of Lead in Soil from Mine Tailings

Lead from mine tailings containing 0.6 % lead was applied at a rate of 12 metric tons per acre of soil and worked in to a depth of 20 cm. The density of the soil is 1.8 g/cm3. To what extent does this add to the burden of lead in the soil? (There are 640 acres per square mile and 1609 meters in a mile.) a) 19 ppb b) 45 ppb

Calculations required for a typical "Calculation of Gas Constant" lab report.

Example of Gas Law Constant Lab Report PLEASE SEE THE ATTACHED FILE FOR THE FULLY FORMATTED PROBLEM 1. A student performs the experiment according to the instructions in this experiment. (SHOW WORK in spaces provided) a. The weight of magnesium ribbon used is 0.0328 grams. How many moles of hydrogen could be collected

Synthesis of a chemical compound: Making alum from aluminum

How do I calculate the amount of alum left over in the following problem? Experiments show that solubility of alum in 25 mL of 1.4 M KOH plus 10 mL of 9M H2SO2 is about 1.0 g at 1.0 oC and 1.7 g at 6.0 oC. Using your measured solution temperature (4.5 oC) estimate the amount of alum left in your chilled solution

mass percent and volume percent of ethyl alcohol in solution

Ethyl alcohol, C2H6O is the alcohol present in liquor. A solution is made up by adding 25.0 mL of ethyl alcohol (d = 0.789 g/mL) to 45.0 mL of isopropyl alcohol, C3H8O (d = 0.7855 g/mL). Assuming volumes are additive, calculate the following: The mass percent of ethyl alcohol in the solution. Ethyl alcohol, C2H6O is

Calories from Fat

A person on a 2500-Cal low-fat diet attempts to maintain an intake of no more than 20% of food energy from fat. What percent of the daily fat allowance is represented by a tablespoon of peanut butter (15.0 g and 50.1% fat)? Fat has a food value of about 9.0 Cal/g. A. 14 % B. 27 % C. 2.7 % D. 0.17% E. 5.4 %

Consumption

From the following reaction please calculate the grams of sulfur dioxide, SO2 produced when a mixture of 50.0 g of carbon disulfide and 72.0 grams of oxegen reacts. Which reactant remains unconsumed at the end of the combustion. How many grams remain? CS2 + 3O2 ----> CO2 + 2SO2

Mole, Empirical and Stoichiometry Calculations

Mole Calculations (Determining Avogadro's Number): 1. Calculate the mass of carbon in a diamond that contains 3.33 x 1024 atoms of C. 2. Calculate the mass of chloroform that contains 1,000,000,000,000 molecules of CHCL3. 3. Calculate the number of NaCL formula units in 1.37 g of table salt. 4. Calculate the number of N2 mo

The Production of Sulfur Trioxide

SO3 can be produced in the following two-step process: FeS2 + O2 ---> Fe2O3 + SO2 S02 + O2 ----> SO3 Assuming that all the FeS2 reacts, how many grams of SO3 are produced when 20.0 g of the FeS2 reacts with 16.0 g of O2?

Stoichiometric Relations Chemistry

The equation for one of the reactions in the process of reducing iron ore to the metal is Fe203(s) + 3CO(g) ??> 2 Fe(s) + 3 CO2(g) a. What is the maximum mass of iron, in grams, that can be obtained from 454 g (1.00 lb) of iron(III) oxide? b. What mass of CO is required to reduce the iron(III) oxide to iron metal?

Chemistry

A car gets 9.2 kilometers to a liter of gasoline. Assuming that gasoline is 100% octane (C8H18), which has a density of 0.69 g/cm3, how many liters of air (21% oxygen by volume at STP) will be required to burn the gasoline for a 1250-km trip? Assume complete combustion.

Balanced chemical equation for biosynthesis

Please help with the following problem. Write the balanced chemical equation for the biosynthesis of ethanol. Label the sucrose and the ethanol in the equation. If you start with one mol sucrose, how many mol ethanol is produced? (Assume complete conversion of sucrose to ethanol.) The density of ethanol is 0.80 g/ml. A

Molecular Weight by Freezing Point Depression of Solution

A 0.573g sample of a nonvolatile solute is added to 15.6g of napthalene and the mixture warmed until melted. The freezing point of the solution was determined and found equal to 78.1C. The freezing point of naphthalene is 80.2C. How do you find out if the boiling pt and the vapor pressure increases or decreases? How do you

Gas Laws - Volume, Density, and Temperature

1.) The density of liquid nitrogen is 0.808 g/mL at -196 degrees Celsius. What volume of nitrogen gas at STP must be liquefied to make 10.0 L of liquid nitrogen? 2.) Calculate the volume occupied by 2.5 mol of an ideal gas at STP. 3.) A hydrocarbon (compound containing only hydrogen and carbon) was analyzed to be 85.7 mass per

Percent by mass composition

While chlorofluorocarbons (CFC) are compounds that seem incredibly useful in industry, they also seem to wreak havoc on the ozone layer. If CFC-211 has a percentage by mass of chlorine of 80.46% and carbon of 10.90%, the rest being fluorine, what is the likely formula for CFC-211?

Forces in gases and in deep space

1.) How much force is required to inflate a high pressure bicycle tire to 95 pounds per square inch (655 kPa) with a hand pump that has a plunger with an area of 5.0 cm^2? 2.) An object exerts a force of 500. N and sits on an area of 4.5m X 1.5m. Calculate the amount of pressure exerted by the object in torr. 3.) During your t

Chemicals and Temperature

1. How small a change temperature can be detect by touch? How could smaller changes in temperature be detected? 2. What would be expect to observe if KHCO3 reacted with HBr? What test would be performed to identify the product? 3. If a reaction called for a minimum of 0.5 moles of table sugar, C6H12O6, and there was only o

Questions of density and volume

In my lab I determined volumes for two unknown metals by two different methods (displacement in a liquid: V=9ml vs. calculation of all sides: V=8.83 cm3 V=5ml V=4.75 cm3 The volumes are not the same. Which do you believe to be more accurate? Why?

Density Comparison of Masses

1. The density of an uncooked egg is much less than that of a hard boiled egg. Would it make any difference in this demonstration if the egg was hard boiled? If yes, explain what you would see if the graduated cylinder contained: a) only water b) only salt water c) 1/2 water, 1/2 salt water 2. Would a comparison of a can (

Density of Metals

1. Which is more dense, lead or brass? How it can determine? 2. A sheet of metal has the dimensions 5mm, 25 cm, 55cm and its mass is 14.7kg. Using the densities of metals, can you definitely tell what metal this is? How?

Understanding molar concentrations/volume /equations

1. molar concentration of a liter solution of HCl that has 65 grams of HCl in it? 2. How many grams of NaCl are needed to make a molar solution of 2 liters? 3. How many grams of a glucose are in 1 liter of 10% mass/vloume glucose solns?

Density, Volume

1. Describe two different ways by which you could measure the volume of a small cube. 2. Which is more dense, lead or brass? 3. If the value occupied by a liquid 48mL and the density if 1.2g/mL, what is the mass of the liquid? 4. A recycling plant has chips of hight density poly(ethylene) (HDPE, d=0.92g.mL) used for pla

A solution containing 292 g of Mg(NO3)2 per liter

A solution containing 292 g of Mg(NO3)2 per liter has a density of 1.108 g/mL. The molality of the solution is a. 2.00 m b. 2.41 m c. 5.50 m d. 6.39 m (See attached file for full problem description)

Moles in a solution

Calculate the number of moles of aluminum in a solution containing 10 grams sample. a. 0.742 mole of Al atoms b. 0.371 mole of Al atoms c. 26.98 mole of Al atoms d. 0.121 mole of Al atoms

Molarity of a HCl Solution

Calculate the molarity of a solution prepared by dissolving 3.12 grams of gaseous HCL in enough water to make 26.8 mL solutions. a. 1.6 M HCL b. 0.8 M HCL c. 3.2M HCL d. 5.4 M HCL