Share
Explore BrainMass

Stoichiometry

Molar Mass of a Compound from Weight

One molecule of a compound weighs 2.03 E-22 g. Its molar mass is: a. 48 gram per mole b. 92.1 gram per mole c. 114 gram per mole d. 122 gram per mole

Volume of Methane

What volume is occupied by 19.6 gram of methane (CH4) at 27 degree Celsius and 1.59 atm? a. 1.71 L b. 18.9 L c. 27.7 L d. 303 L

Grams in a Solution

How many grams of NaCl are contained in 350 ml of a 0.25 M solution of sodium chloride? a. 41.7 gram b. 5.11 gram c. 14.6 gram d. 87.5 gram

Thermochemistry with Heat of Reactions and Standard Enthalpies

1. (Stoichiometry/Heats of Reactions) a. How many kilojoules of heat energy are released when a 63.4-g sample of magnesium metal is completely converted to magnesium oxide according to the equation below? b. How many grams of oxygen gas are used up during an enthalpy change of -292 kJ? 2 Mg(s) + O2(g) -> 2 MgO(s)

Atomic Weights - The Atomic Mass of N Relative to H

Ammonia is a gas with a characteristic pungent odor. it is sold as a water solution for use in household cleaning. The gas is a compound of nitrogen and hydrogen in the atomic ratio 1:3. A sample of ammonia contains 7.933 g N and 1.712 g H . What is the atomic mass of N relative to H?

Concentration of sodium chloeide

What would would the steps to find the concentration of sodium chloride in the final solution if 24.34 mL of 0.113 M BaCl2 completely reacts and the total volume of the reaction is 110.4 mL, give the reaction: BaCl2(aq)+Na2SO4(aq)ds=BaSO4(s)+2NaCl(aq)

Ionic Equilibria

(See attached file for full problem description) --- 1. When blood is donated, sodium oxalate solution is used to precipitate Ca2+, which triggers clotting. A 104-mL sample of blood contains 9.7à?10-5 Ca2+/mL. A technologist treats the sample w/100.00 mL of .1550 M Na2C2O4. Calculate [Ca2+] after the treatment (Ksp of C

Calculating mass with Q=It

"Calculate the mass of chromium produced in 1.0 hour by the electrolysis of molten CrO3 with an electrical current of 15 A." The answer is 4.85 g, but I'm not entirely sure how to get there. Don't I need the reaction in order to know how many electrons are produced by the electrolysis? I think I first use Q = (I)(t) = (15)

Determining Density from Volume

I have a 40 lb container that measures 14x20x30 and need to find the density. I also have another 40 lb container that has a volume of 1.9 gal. How do you find the density for both to see which one is lighter?

Properties of solutions - Propylene Glycol

9) Calculate the mass of propylene glycol (C3H8O2) that must be added to 0.340 kg of water to reduce the vapor pressure by 2.88 torr at 40 °C. 10) Calculate the freezing point and boiling point of an antifreeze solution that is 50.0 % by mass of ethylene glycol (C2H6O2) in water. 11) Calculate the freezing point and boili

Simple explanation needed

10kg petrol is burned in a car engine. What two main chemicals come from the exhaust and how much of each in kilograms?

Density: Mass and Volume

A sphere made of nickel (d=8.908g/cm^3) has a diameter of 8.20 cm. What mass of nickel was used in making the sphere? (V of sphere = 4/3 pi r^3).

Given % yield, calculate grams obtained

Balance the following equation: AsF3 + CCl4 ---> AsCl3 + CCl2F2 the theoretical yield of CCl2F2 = 1.68 moles if the actual yield was 74.3% in the reaction, how many grams of CCl2F2 were obtained

Precipitate from Reactions

Silver nitrate reacts with iron(III)chloride Fe Cl3 to give AgCl and Iron(III)nitrate Fe(NO3)3. A solution with 18 grams of AgNO3 was mixed with a solution. 32.4 grams of FeCl3. How many grams of which reactant remains after reaction?

Combustion of hydrocarbons

Propane, C3H8, in a tank that is usually the size of a basketball is often used for grills. a) Write a balanced equation for the combustion of propane. b) Calculate the number of moles of oxygen required to burn 5000.0 g (11.0 lbs) of propane. c) Calculate the number of kilograms of O2 required to burn propane.

Moles and Molarity Pproblems

A 12.0% sucrose solution has a density of 1.05g/cm^3. The number that gives the best value for the mass of sugar in 55mL of this solution is? I need step by step answer for this question please. What is the Molarity(m) of a solution that contains 73.5g of 1,4-dichlorobenzene,C6H4Cl2, in 500mL of carbon tetrachloride? (The

Chemistry calculations including calculating molecular formulas

What is the molecular formula of a compound that contains 42.87% carbon, 3,598% hydrogen, 25.00% nitrogen and 28.55 oxygen and has a molar mass between 165 and 170? How many grams of lithium contain the same number of atoms as 2.50 Kg of zirconium? If the molar mass of a binary compound has a molar mass between 27 and 28 a

The fluoride ion is very toxic.

The fluoride ion is very toxic. Not only does it interfere with glycolysis, but if forms an insoluble precipitate with calcium ions (Ksp = 4.13 x 10-11). Give an explanation as to why CaF2 is insoluble; whereas, other calcium halides are soluble in the order CaI2>CaBr2>CaCl2. How much fluoride (as sodium fluoride) would you h

Stochiometery 4

When 19.8g butane, C4H10 is burned with excess oxygen: 2C4H10g + 13O2g -----> 8CO2g +10H2Og How many grams of oxyen are consumed, how many grams of CO2 & H2O are produced?

Combustion Reaction Problem

Consider the combustion of methane, CH4 CH4 (g) + 202 (g) ----> CO2 (g) + H2O (g) Suppose 8.00g of CH4 is allowed to burn in the presence of 6.00g of 02. How much (in grams) CH4, 02, CO2, and H2O remain after the reaction is complete? Please show the required calculations.

Average Density of the Sun

I need some help figuring this question out: The sun has estimated mass of 2x10^36 and the sphere is of average radius of 6.96x10^5 km, calculate the average density of the sun in units of kg/km^3; kg/m^3; g/cm^3 and lbs./ml (hint: use answer from c to convert).