Chemistry

answer

watching

130

views

29 Nov 2019

I'm really stuck on how to approach this problem. Please show workModel 1-Assume that each molecule is a cube with the sides of length "t".Find: volume of a molecule of cetyl alcohol (v=t^3)number of molecules in the monolayer (N=V/v)Number of moles in the monolayer (n=m/242.50)number of molecules in 1 mole; avogadro's number (N0=N/n)Model 2- Assume each molecule is a rectangle with the longer sides five times the shorter side. The longer side of the rectangle will be the monolayer thickness, t.Find: volume of a molecule of cetly alcohol [v=t(t/5)(t/5)]number of molecules in the monolayer (N=V/v)Number of moles in the monolayer (n=m/242.50)avogadro's number (N0=N/n)

answer

watching

130

views

For unlimited access to Homework Help, a Homework+ subscription is required.

You have 0 free answers left.
Get unlimited access to 3.8 million step-by-step answers.

Get unlimited access

Already have an account? Log in

Bunny GreenfelderLv2

17 Dec 2019

Unlock all answers

Get 1 free homework help answer.

Already have an account? Log in

Join us on Discord

Chemistry Study Group

Join now

Related questions

I'm not sure how to go about number 5

M 121 1 201 Ideal Gas Law (PV n Experiment to T ) Determine the Ideal Gas Constant R 1. Conduct basic measurements, measurement , mathematical calculations and conversions for of volume, pressure, and temperature: calculate percent error and account for sources of error in an e xperimental result name and by following safety proced ty experiments for a redox reaction by using equipment identifiable by form chemical calculations using mass, mole and volumes and idenify limitatios of measuring devices in order to state the uncertainty/significant figures in measurements and calculation results. 5. Demonstrate a proficiency in relating the chemistry of gases to everyday phenomenon. Introduction Molecules in gases have very little attraction for one another, because relative to their size, they are so far apart from each other. For this reason we can often assume that a gas behaves "idcally." meaning that the physical behavior of the gas is independent of the composition of the gas. If a gas behaves ideally, then its physical properties can be described by the Ideal Gas Equation: Let's consider why the variables in the ideal gas equation have the relationships expressed in Equation 1aã The ideal gas equation assumes that there are no attractive forces between gas molecules. One can picture two billiard balls bouncing off one another in a totally clastic collision. If these molecules are placed in a balloon the collisions will occur not only with each other but also with the wall of the balloon, causing the balloon to expand. This expansion can be measured as a volume (V). More molecules will cause more collisions and thus more expansion. Therefore the quantity of molecules or number of moles (n) is directly proportional to the volume, and thus volume and number of moles appear on opposite sides of the equation. Another factor to consider is the kinetic energy of these molecules. Kinetic energy is related to the temperature (T) of the molecules, in that the kinetic energy. If the collisions with the wall of the balloon are happening at a very high speed due to high kinetic energy, the collisions will be harder and more frequent and thus the wall of the balloon will be pushed out further (a larger volume) than if the kinetic energy were less. The result is that volume is also directly proportional to the temperature. This relationship is seen in Equation la with (T) on the right side of the equation and (V) on the left. higher the temperature the greater the considered. While the molecules inside the balloon are pushing the balloon out, there are also molecules in thea Finally the pressure of the outside environment (atmospheric pressure) needs to be 59

Activity accounts for electrostatic interactions. For well-separated ions, electrostatic interactions are minimal; ions behave as at infinite dilution. As concentrations increase, distance between ions decreases and electrostatic interactions of force and energy increase. Consider the distance d between ions in solution. A spreadsheet is advisable. Find the equation for the distance between two ions in solution when the ions are present at a concentration c (mol/cm^3). In a spreadsheet, for log c from -12 to -2, calculate c and d. Increments of 0.5 in log c are appropriate. Units are c in mol/cm^3 and d in cm. Include calculation of concentration in molar units and separation distance in nm. What is the volume of one water molecule? What is the diameter of one water molecule in nm? Consider number of water molecules between ions as a rough estimate of the strength of electrostatic interactions between the ions. In the spreadsheet, how many water molecules are between two adjacent charges as a function of concentration? Plot log #waters versus log c(M). At what concentration is there about one water molecule between two ions? Comment on the shielding between two ions as concentration increases. In addition to shielding ions, water can be bound to ions. Once water is bound to ions, it is no longer free and therefore no longer part of the solvent. This increases the effective concentration of the ions because the solvent volume and mass has decreased. This is the Stokes Robinson model for activity, which is not explored in detail here. But, consider how bound water increases with c. (Part d is based in volumes, not distance between ions.) For a monocation, such as Na^+, the number of bound waters changes with ion size. For purposes of discussion, allow 5 bound waters per monocation. Anions such as Cl^- hold fewer waters; estimate this as 1. Then for every NaCl dissolved in solution, 6 waters are bound. To the spreadsheet, calculate the moles of each NaCl and water in cm^3. This calculates total moles of water per cm^3. Calculate the moles of free water at each concentration, which is total moles of water/cm^3 - 6 times moles NaCl/cm^3. Plot total moles of water, moles of free water, and moles of bound water per cc versus log c(M). At about what molarity of NaCl does the bound water begin to impact the free water? How does this correlate with the upper limit for Extended Debye Huckel (EDH)? Does EDH account for free and bound water? Density is 1.00 g/cm^3. Calculate volume of free water per cm^3. At what NaCl concentration does the model fail? How do you know? Calculate the effective concentration of NaCl as the moles of NaCl per cm^3 per volume of free water per cm^3. Calculate ratio of effective to real concentration of NaCl. What is c(M) where there is a ~2% change? a 20% change? a > 100% change? At about what concentration does free versus bound water become important? Calculate the mole fraction of NaCl (moles NaCl/(moles NaCl + total moles H_2O)) at each c. Report mole fraction in ppm. What mole fraction (ppm) corresponds to ~2%, a 20%, and > 100% change found in the just previous question? Fill in the blank or select an answer as appropriate. At ~ M, activity is not well modeled by extended Debye Huckel (EDH) as EDH does not account for free and bound waters. As concentration of ions increases, activity effects are more/less pronounced.

Weekly leaderboard

Home

Homework Help 3,900,000

Chemistry 830,000

Unlock all answers

Related textbook solutions

Basic Chemistry

Principles of Chemistry Molecular Approach

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related questions

Weekly leaderboard