Explore BrainMass

General Chemistry

Full Ionic and Net Ionic Equations

Write the ionic and net ionic equations for the following reactions. a) AgNO3 (aq) + Na2SO4, (aq)-----> B). BaCl2 (aq) + ZnSO3 (aq)-------> C). (NH4)2CO3 (aq) + CaCl2 (aq)------>

Geometric Structure and Localized Bonding Models

Geometric Structure and Localized Bonding Models (also as attachment) 1. For each of the following chemical species: (i) write acceptable Lewis structures (including major resonance contributors and indicating formal charges); (ii) designate oxidation states for all atoms; and (iii) draw the stereochemical structures predi

Ionic, polar covalent and non-polar compounds

How do you tell if a compound is ionic, polar covalent, or non-polar? Find out for these compounds (Big numbers are used to represent the number of atoms because they are all 1 molecule.) a) Na2SO4 b)KOH c)(NH4)2SO d) C6H14 e)C2H5OH f)H20

Ksp and Solubility: Concentrations of Ions in Solution

What are the concentrations of each of the ions in a saturated solution of PbBr2, given the Ksp of PbBr2 is 2.1 x 10^-6? I get stuck in solving this question when I get to the equation 4(x^3)=2.1 x 10^-6 and I don't know how to get to the answer x = 8.07 x 10 ^-3 M which is supposedly the concentration of Pb 2+. Real

Explanation of melting point & boiling point deviations

I only need help on question 3. I have perfomed the labs for melting pt and boiling pt on the following four and only need help with question 3 acetonitrile (C₂H₃N): GIVEN MP = -45.5C, BP = 77.3C My results MP= -46.8 C, BP = 79.4 C benzene (C6H6) GIVEN

Molar solubility product of barium fluoride

Please help with the following problems. Provide step by step calculations for each. 5.[a] The molar solubility of barium fluoride, BaF2, is 7.5 x 10-3 M. Calculate the solubility product constant [b]Calculate the molar solubility of lead fluoride, PbF2 in water, Ksp = 2.7 x 10-8 6.Calculate the molar solubility of bism

Calculating the Pressure of Gas Sample in a Manometer

In a manometer the mercury level at the open end of the tube is 215 mm higher than at the closed end of the tube. If the atmospheric pressure is 1 atm, what is the pressure of the gas sample in units of torr? A)1.28 torr B)545 torr C)975 torr D)215 torr

Alkanes and Boiling Points

Which of the following shows the alkanes in correct order from lowest to highest boiling points? A) hexane, pentane, butane, propane, ethane, methane B) hexane, ethane, propane, butane, pentane, methane C) methane, ethane, propane, butane, pentane, hexane D) metane, ethane, propane, pentane, butane, hexane

Ozone Layer - What it does

1. How does the ozone layer protect the earth from ultraviolet radiations? 2. What steps need to be taken to contain the depletion of the ozone layer?

PowerPoint Presentation on the Element Boron

BORON I am looking for someone who is knowledgeable with PowerPoint. I need help getting started with this project and knowing how to go about this. My classmates told me finding a scientific article is the hard part to this project, so I want someone to help me with that also. _______________________________________

Butane and Hexane - Why Different Boiling Points

Butane, CH3CH2CH2CH3, has a boiling point of 0.4ºC, and hexane, CH3CH2CH2CH2CH2CH3, has a boiling point of 69ºC. Both are nonpolar molecules. Explain the large difference in the boiling points of these two substances.

[Pb^2+] and [I^-] in the saturated solution

A 20.1 g sample of NaI is dissolved in water to make 0.204 L of solution. The solution is then saturated with PbI2. What will be [Pb^2+] and [I^-] in the saturated solution? (in M)

compute solubility product Ksp

An AB2 salt has a solubility of 267 mmol/100g. Assuming that 1 L of solution weighs 1 kg. Compute solubility product Ksp.


What volume of 0.101 M HNO3 is required to neutralize 23.7 mL of 0.00517 M Ba(OH)2 mL

Finding Molar Concentration

You have a 50 µM solution of sodium phosphate. Express this as a molar concentration, as a millimolar concentration.

States of Matter/Gas/Motion/Force

How do you think the motion of molecules in a gas (at rest) would differ from the molecules in a tornado? Why does the same amount of liquid when left in a wider and flatter container evaporate quicker than when left in a narrower and deeper container?

General Chemistry Problems

10.40) Many gases are shipped in high-pressure containers. Consider a steel tank whose volume is 65.0L and which contains O2 gas at a pressure of 16,500kPa at 23°C. a. What mass of O2 gas does the tank contain? b. What volume would the gas occupy at STP? c. At what temperature would the pressure in the tank equal 150.0atm? d. W

Assorted General Chemistry Problems

8.20) a. The lattice energies of NaF and MgO are 910kJ/mol and 3795kJ/mol. Account for the difference in these two quantities. b. Account for the difference in lattice energies of MgCl2 (2326 kJ/mol) and SrCl2 (2127kJ/mol). 8.28) Calculate the lattice energy of CaCl2. Is this value greater than or less than the lattice energ

General Chemistry Problems

5.38) Consider the following reaction: CH3OH (g) ---> CO (g) + 2 H2 (g) deltaH = +90.7 kJ a. Is heat absorbed or evolved in the course of this reaction? b. Calculate the amount of heat transferred when 45.0 g of CH3OH (g) is decomposed by this reaction at constant pressure. c. For a given sample of CH3OH, the enthalpy change

Assorted General Chemistry Problems

1.28) a. A cube of osmium metal 1.500cm on a side has a mass of 76.31g at 25°C. What is the density in g/cm3 at this temperature? b. The density of titanium metal is 4.51g/cm3 at 25°C. What mass of titanium displaces 65.8mL of water at 25°C? c. The density of benzene at 15°C is 0.8787g/mL. Calculate the mass of 0.1500L of be

DeBroglie Equation Problems

Calculate the mass for one photon of the following wavelengths of light: 1. red light with wavelength of 616 nm.........in kg 2. radio signal with frequency of 99.0 MHz........in kg 3. a photon of X-ray with energy of 2.30 x 10-15 J........in kg

Calculate the deBroglie Wavelength

Calculate the "deBroglie wavelength" for each of the following: 1. an electron moving at 0.82 times the speed of light...... in meters 2. a 125-g ball moving at a speed of 13.6 m/s.....in meters 3. a 61-kg person walking at a speed of 2.00 km/hr....in meters These answers explain why macroscopic (large) objects a

Lyman Series for H

The Lyman series in the hydrogen atom corresponds to transitions that originate from the n=1 level in absorption or that terminate in the n=1 level for emission. Calculate the energy, frequency (in inverse seconds and inverse centimeters), and wavelength of the least and most energetic transition in this series.

Solving 7 Chemical Equations

I desprately need help solving these chemical equations to help me to study for an exam. Rules for Solving Chemical Equations: 1. Write the chemical reaction in word form 2. Post your symbols 3. Post diatomics (for single units only) 4. Post oxidation numbers for compounds 5. Post subscription (for compounds onl

Assorted General Chemistry Problems

1) Given the following data table of average bond enthalpies, estimate the ΔH^rxn for the reactions 2H2+O2-- 2H2O Bond Average (kJ/mol) H-H 436 O=O 498 H-O 423 2) Draw eight distinct, valid Lewis resonance structures for the molecule XeO3. 3) Which structure or structures is or are mo

Assorted General Chemistry Problems

1) List the following gases in order of increasing root-mean-square speed, all at the same temperature: H2, He, O2, Ne 2) Under what conditions of pressure and temperature is a real gas most expected to deviate from ideal gas behaviour? 3) What intermolecular interactions would be the strongest between molecules CH2Cl2?