Share
Explore BrainMass

Stoichiometry

Limiting reactants in stoichiometry

If 45.7 grams of Na reacts with excess H2O, how many grams of each product will form? (You need to determine the equation of the reaction in order to determine the answer.) I am working as a substitute teacher and need to teach this material to my class - please explain the steps needed to solve this question (at the high sc

Conversion problem

I prepared a 1.0 mM solution of Benzoic Acid in methanol and I now need to convert it to 50ppm. ???? How???

Calculating Molarity and Molality

Question: A sodium chloride solution has a molarity of 1.250 mol/L and a density of 1.050 g/ml. Calculate molality, the mole fraction of water, and the percent by mass of sodium chloride.

Solve: Distance, Velocity, Density and Volume

Questions: 1. If the sun which is 93,000,000 miles away away from Earth was to go out, how long would it take for us to know that this had happened? Light travels at a speed of 3 x 10^8 meters/second. 2. What would the density be (in g/cm^3) of a block that is 4 cm by 15 cm by 12 cm, and has a mass of 4.3 kg? 3. An ob

Mass Balance Problem

Please see the attached file for full problem description. --- Q1. Starting with a pulp with a water content of 99%, how much water must be removed to obtain one ton of paper containing 60% water? Solution. Water removed Pulp

Calculating the Mass of Compounds

Please view the attached file to see the various compounds I need to calculate the mass of. I am having some difficulty approaching these questions.

Empirical Formula

A major oil company has used a gasoline additive called MMT to boost the octane rating of its gasoline. What is the empirical formula of MMT if it is 49.5% C, 3.2% H, 22.0% O, and 25.2% Mn? empirical formula_______________________________

Molarity

5. Calculate the sodium ion concentration when 60.0 mL of 6.0 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate.

Boiling Point Elevation

I'm doing boiling point elevation and the formula is: deltaT_b = k_b * m * i (k_b = 0.52 degrees C/m for water) I don't know how to use this calculation with this problem: Calculate the boiling point of an aqueous solution containing 3.8% by mass of NaCl. Do I take 3.8% of NaCl's mass of 58.44g? How do I set up the equatio

Density of Oil

If a serving of oil is exactly 1 tablespoon, which has a mass of 14g, and there are 96 servings in the container, what is the density of the oil in grams per milliliter (g/ml)?

Density

A cylindrical bar of gold that is 1.5 in. high and 0.25 in. in diameter has a mass of 23.1987g, as determined on an analytical balance. An empty graduated cylinder is weighed on a triple beam balance and has a mass of 73.7g. After pouring a small amount of liquid into the graduated cylinder, the mass is 79.16g. When the gold cyl

Chemistry Problems

1. The following reaction occurs: CaCO3 + 2H- -> Ca2+ + CO2 +H2O If a 25gm sample of calcium carbonate is added to a 75.5 ml HCl (density = 1.125gm/cm3, 26% HCl by mass), calculate the molarity of the HCL remaining in solution (if any) after the reaction is complete. Assume no volume change. 2. A sample of coc

Conc. of an ideal solution as function of T and position in a strong gravit. field

An ideal solution with solute density 1.05 and solvent density 1.00 is subject to a huge gravity force field, a linear function of postition, F=kr, k is a constant and r is the position along the field. Derive the concentration as a function of T and position r along the field. (Hints: express gravitational potential as functi

Finding limiting reactant, theoretical yield, and actual yield

An electric furnace produces phosphorus by the following reaction: Ca3(PO4)2(s) + C(s)+SiO2(s)= CaSiO3(s)+CO(g)+P(I) An initial reaction mixture contains 1500g calcium phosphate, 250 g carbon and 1000g silicon dioxide. a) What is the limiting reactant? b) What is the theoretical yield of phosphorus? c) After the reaction

Physics

Imagine that we give N2(+), O2(+) and (NO)+ ions the same velocity of 30.0 km/s and then send them into a mass spectrometer where the magnetic field strength is B=8.5MN/C. How far would the spot on the photographic plate be from the entry point for each ion, assuming that each ion completes one-half of an orbit. The atomic mas

Simplest Formula Analysis

50.0 g of an oxide of Chromium (Cr) was found to contain 13.28g of potassium (K), 17.68 g of Chromium (Cr) and 19.04 g of oxygen (O). Find the simplest formula...

Determine Concentration of Potassium Chromate to Use (Mohr Titration)

A titration of 0.100 M Cl^- with 0.100 M Ag^+ used an end point where silver chromate gives an orange precipitate. Select the concentration of potassium chromate that must be present so the orange-colored silver chromate precipitate will appear just when 99.5% of the chloride has been precipitated. Given: Ksp of AgCl = 1.0 x 10

Oxygen reactions

Oxygen can be preparead in a lab by the reaction: 2KCLO3 = 2H2(g) + O2(g) Question: How many grams of KCLO3 must be reacted to produce 100 g of O2?

Daltons Law of Partial Pressures

Dry air near sea level has the following composition by volume: N_2, 78.08%; O_2 20.94%; Ar, 0.93%; CO_2 0.05%. the atmospheric pressure is 1.00 atm. calculate the partial pressure of each gas in atm and the concentration of each gas in moles per liter at 0 degrees C.

Gas stoichiometry

C2H5OH burns in air: C_2H_5OH(l)+O_2 --->CO_2(g)+H_2O(l) balance the equation and determine the volume of air in liters at 35.0 C and 790 mmHg required to burn 227 g of ethanol. assume that air is 21.0 percent O_2 by volume.

What is the oxidation reaction for Ag + NaCl?

For my AP chemistry lab, I was supposed to find the percent of silver in a dime. I started out with the formula: Ag + NaCl → AgCl +Na. The dime was put in a covered beaker with NaCl. However, during the experiment oxygen was added as one of the reactants, accidentally. The precipitated silver chloride was obviously con

Mass percentage of sodium chloride in a mixture

A sample of a mixture containing only sodium chloride and potassium chloride has a mass of 3.5650g. When this sample is dissolved in water and excess silver nitrate is added, a white precipitate (silver chloride) forms. After filtration and drying, this precipitate has the mass 7.9143g. What is the mass percentage of sodium ch

Calculating ppm

The chloride in a saline solution was determined by the Volhard method. A 25 ml aliquot of the solution was acidified with 2 ml of dilute HNO3 and treated with 25 ml of .1749 M AgNO3 (fw 169.9), causing precipitation of AgCl. After addition of several ml of nitrobenzene, the solution required 26.40 ml of .1575 M KSCN to reach t