Explore BrainMass


Molar Volume from solution samples

I have premass samples of NaCl (1.16 grams) and CaCl2 (2.24 grams), I need to create a 1.0M solution of both slats using distilled water. How much distilled water do I use per salt?

Stoichiometric Conversions

An empty vial weighs 55.32g. 1) If the vial weighs 185.56g when filled with liquid mercury (d=13.53 g/cm^3), what is its volume? 2) How much would the vial weigh if it were filled with water (d = 0.997g/cm^3 at 25 degrees Celsius)? [show all your steps in answering this question] Volume of the vial.

Structures of Hydrocarbons

Unlike cyclopentadiene, 1,3 cyclohexadiene can be stored for long periods at room temperature. When 1,3 cyclohexadiene is heated at 180 degrees C for two hours, a 30% yield of two products A and B, each of empirical formula C12H6, can be isolated. Hydrogenation of either A or B gives the same hydrocarbon C, of empirical formula

Finding atoms in a sample

Avogradro's number (6.022 x 10^23 atoms/mol) is a useful number that can be used to calculate a number of different values for compounds/elements. One important value is finding the number of atoms in a specific mass of an element. The solution includes a general step-by-step method of finding the number of atoms in a specific

Molar problem of Iron(III)nitrate

Question: If you want to make 2.5 liters of a 1.2 Molar solution of Iron(III)nitrate, how many grams of Iron(III) nitrate would you need to weigh out? This is a beginners easy class, so the teacher keeps it simple and not complex. We figure out the problems using conversion factors and I want to know how to set it up and h

Aluminum Nitrate

How many grams of aluminum nitrate would be needed to make 0.95 ml of a solution with a normality of 3.2? I need to know how to set up this problem and then make sure I end up getting the right answer on the calculator.

Molal Solution/Mass of Water and Mole Fraction

What mass of water must be used to dissolve 20.0 g of C2H5OH to prepare a 0.0500 molal solution of ethanol? 8.70Kg how? Calculate the mole fraction of ethyl alcohol C2H5OH in a solution that contains 230 grams of C2H5OH and 312 grams of benzene C6H6? 0.56 How?

Molality/Molarity Calculations

Please help me calculate the molality of a solution that contains 51.2 g of C10H8 in 500 ml of carbon tetrachloride. The density of CCl4 is 1.60 g/ml. I also need help calculating the molarity of a solution that contains 9.0 g of (COOH)2 in 1500 ml of solution.

Molarity and Mass

A 30.0ml sample of a solution of NaCLO3 that contains 1.06 g of NaClO3 is to react with a solution of I2. What is the molarity of the NaClO3 solution? Also, what mass of Molybdenum3 oxide, Mo2O3 will be completely oxided to potassium molybdenum, K2MoO4 by 35.Oml of .200 MkMnO4.

Reaction of FeSO4 and KMnO4

An impure 0.500 gram sample of FeSO4 reacts with 20.0 ml of 0.0200 M KMnO4 Assuming that the impurities do not react with KMnO4 what is the percentage of FeSO4? The equation given is MnO4- +8H +5Fe+2 -------->Mn2 +5F3+ + 4H2O so far I got: .0200l *.0200M MnO4- =4*10-4 Moles of MnO4 How do I get to the moles of Fe?

the mass of CuO in the mixture

A 0.500 gram mixture of Cu2O and CuO contains 0.425 grams of Cu. What is the mass of CuO in the mixture? I have the answer it is .21 grams of CuO I just need a formula and step by step instructions on how to arrive at this answer. I would love this answer back as soon as possible thank you. -Paul L. Hollis

Molarity and Molality

What is the molarity of 2500ml of a solution that contains 160 grams of ammonium nitrate? How do you set this problem up instrucrtor gave answer as .800M? How do you calculate the molality of a solution that contains 51.2 g Naphthalene, C10H8,in 500ml of carbon tetrachloride. The density of CCl4 is 1.60g/ml?

Titration: Finding Percent CuSO4 in a Solution

Copper 2 ions can be determined by the net reaction 2Cu +2I- + 2S2O3)2----->2Cu(s)+S4O6)2- A 2.115-g sample containing CuCO4 and excess KI is titrated with 32.55ml of o.1214M solution of NA2S2O3. What is the percent CuSO4? (159.6/g mole in the sample)

Equations and Formulas

1. Write the equation for the decomposition of the hydrate, CuSO2*XH2O. 2. Record the following masses: (a) mass of the empty crucible (g): 53.200g (b) mass of the crucible and hydrate (g): 58.200g (c) mass of the crucible and pure salt (g): 56.396g 3. Calculate the following: (a) mass of wa

Moles to Moles

1. Record and calculate the following: (a) Mass of copper used in the reaction (g) 114.815g (b) Moles of copper used in the reaction (a simple stoichiometric conversion of mass to moles using the molar mass for copper of 63.5 g/mol. Show your work). (b) Mass of beaker and dry silver (g) 313.867

General Chemistry

Question 11.2 Which one of the following does not occur as diatomic molecules in elemental form? Bromine Nitrogen Hydrogen Sulfur Oxygen Question 12.2 Sulfur forms an ion with a charge of _______. +3

General Chemistry

Question 1 If matter is uniform throughout and cannot be separated into other substances by physical means, it is _______. a compound an element a homogeneous mixture either an element or a compound a heterogeneous mixture

Concentration of a Dissolved Solution

A solution is prepared by dissolving 3.50 grams of NH4Cl in enough water to make 250 mL of solution. What is the concentration of this solution please provide step by step instuctions.

Concentration of the solution expressed as % (w/w)

An aqueous solution is found to have a density of 1.04g/mL. If the solution was prepared by dissolving 45.0 grams in enough water to make 1.00 L of solution, what is the concentration of the solution expressed as % (w/w)? please provide step by step instructions, Do not know where to begin, or direction

Mole Conversions

The question reads: Ammonia used to make fertilizers for lawns and gardens is made by reacting nitrogen with hydrogen N2(g) + H2(g) ----> NH3(g) a. Balance the equation (I understand this.) b. Find the number of moles of ammonia formed when 1.34 moles of nitrogen reacts. c. Find the mass in grams of nitrogen r

Find Molecular Formula

A Compound containing only carbon, hydrogen and oxygen was analyzed and found to contain 70.6% carbon, 5.9% hydrogen, and 23.5% oxygen, by mass. The molecular weight of the compound is 136 amu. What is the molecular formula? a. C8H4O b. C8H8O2 c. C9H12O d. C4H4O e. C5H6O2.

Calculating Mass: Example Problem

What is the mass of Cu produced if 10.0 g of Cu2S reacts with 16.0 g of O2 as follows: (mass of one mole: Cu= 63.5 g, O = 16.0 g, S = 32.1 g) Cu2S + O2 -> 2Cu = SO2 a. 7.99 g b. 3.99 g c. 65.5 g d. 31.8 g

Boiling Point Elevation of Chloroform

Boiling Point Elevation. What is the boiling point of a solution made by dissolving 0.7250 grams of C14H10 in 14.50 grams of chloroform (CHCl3)? The normal boiling point for chloroform is 61.70°C and its boiling point elevation constant is 3.63°C/m.

Mass Assembly Questions

Fill in the blanks and please explain the steps to reach the solution. Experimental quantities: KCLO3 Mass of salt 4.5 - 5.0 g 1st quantity of water 10 g 2nd 2g 3rd 8g 4-5g 5-5g 6-10g Mass of assembly: 29.60 g Mass of assembly + salt+ water after 4th addition: 39.05 g Mass of assembly + salt 33.80 Problem: Mass o

Empirical Formula of a Hydride

1. The phosphine that is produced by the reaction of water on calcium phosphide contains an impurity, another gaseous hydride of phosphorus, this hydryde contains 94% phosphorus and 6% hydrogen by mass. Calculate the emphirical formula using the percentages. 2. At 136.5C and a pressure of 760 mmHg, 0.22g of the hydride occup

Rate of rxn given concentrations and rate constant

For the concentration of hydroxyl radical of 7.5E06 molecules/cm3 and a carbon monoxide concentration of 18 ppm, calculate the rate of its reaction with atmospheric carbon monoxide at 11 degrees C, given that the rate constant for the process is 5E-13 E-300/T molecule-1 cm3 sec-1. Hint: Convert the rate constant to a numerica

Concentration and Molarity

A. Explain how to prepare 25 liters of a 0.10 M BaCl2 solution, starting with solid BaCl2. b. Specify the volume of the solution in (a) needed to get 0.020 mol of BaCl2.