5.06c Find the mass/volume percentage for a solution prepared

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來自 University of Kentucky 的課程

Chemistry

615 個評分

University of Kentucky

Chemistry

615 個評分

This course is designed to cover subjects in advanced high school chemistry courses, correlating to the standard topics as established by the American Chemical Society. This course is a precursor to the Advanced Chemistry Coursera course. Areas that are covered include atomic structure, periodic trends, compounds, reactions and stoichiometry, bonding, and thermochemistry.

從本節課中

Week 5

This unit will delve into the quantitative relationships we can determine from a balanced chemical equation to determine the relative amounts of substances needed to react or the amount of products formed. We will also explore limiting reagents and percent yield to address practical aspects of chemical reactions because there may be leftover reactants and/or incomplete formation of products.

5.01 Stoichiometry of Chemical Reactions: Mole to Mole 8:19

5.01a How many Moles of water are produced1:11

5.01b How many Moles of CO2 are produced 1:47

5.02 Stoichiometry of Chemical Reactions: Mass Relationships11:02

5.02a How many grams of magnesium are required 2:27

5.02b How many grams of magnesium do we need 4:34

5.03 Limiting and Excess Reagents11:18

5.04 Limiting and Excess Reagents: Calculations 7:57

5.04a How many grams of H2S can be formed 4:13

5.04b What mass of excess reactant will remain 6:31

5.05 Theoretical & Percent Yields 9:56

5.05a Methyl Salicylate is prepared5:48

5.05b A student needs 625 g of zinc sulfide5:32

5.06 Solution Concentration 15:16

5.06a Find the mass percentage for a solution prepared 1:56

5.06b Find the volume percentage for a solution prepared 1:51

5.06c Find the mass/volume percentage for a solution prepared 2:39

5.06d What is the molarity of a solution made 2:23

5.06e How many grams of LiCl do we need 2:44

5.07 Dilution of Solutions7:16

5.07a What is the concentration of the solution 1:45

5.08 Solution Stoichiometry 9:06

5.08a What volume of HBr is required 5:03

與講師見面

Dr. Allison Soult
Lecturer
Chemistry
Dr. Kim Woodrum
Sr. Lecturer
Chemistry

Find the mass/volume percentage for

a solution prepared from 15 grams of ethanol and a 100 millilitres of

acetone and we're given the density of both of those solutions.

So the first thing we need to do is remember what a mass/volume percentage

looks like when we do that calculation.

So we know we're going to have the mass, in units of grams

over the volume, and that will be in units of milliliters.

And, this mass will be of the solute, and the volume will be of the solution.

So, it's going to include, both the solute and the solvent.

So, what we look at first is figuring out which one is our solute.

We see that ethanol is present in the smaller amount, so

that's going to be our solute.

And that the acetone is present in the larger amount, so

that would be the solvent.

And together, both of them make up the solution.

So, if I need the mass of solute, I already have that information, that's

given in the problem here, so I don't need to do the calculations for that.

And it's asking for the volume of solution.

Well I have the volume of the acetone.

But I don't have the volume of the ethanol.

And so I'm actually going to have to start the problem by figuring out the volume of

ethanol, so that I know the volume of the solution.

Because remember both of those things make up the solution.

So if I have 15 grams of my ethanol, or ETOH as an abbreviation.

And I'm going to use my density that's given, 0.789 grams per milliliter.

Notice that I put the grams on the bottom so that grams and grams would cancel, and

then I can find out that I have 19.0 milliliters of ethanol.

So now I have the mass of my solute which was the ethanol, and

I have the volume of the solvent,

the acetone, as well as the volume of the solute, which is the ethanol.

So I can find the volume of my solution.

So I put in my mass which is 15.0 grams,

over the 100 millilitres from the acetone plus the 19 millilitres,

from the ethanol, and I multiply that by 100 and what I find is that

the percentage is 12.6%, and I put it M/V, just

to indicate that that is the percentage based on the mass volume percentage.

We can find other percentages as well, but this is what this specific one is.

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