week 3 concepts edapt
Both the volume of the solution and solvent mass have a large effect on the % mass/volume concentration. Use the formula mass of solute in grams/solution volume in ml *(100) %
0.003 grams in 15 ml & 0.006 grams in 20 ml are not significantly impaired, 0.01 grams in 12 ml & 0.006 grams in 5 ml are impaired.
Fill in the number of each atom on the reactant side and the product side.
1 Ca 1 2 O 2 4 H 4 2 Br 2
1 FeCl2(s) + 1 H2O(l) →
1 FeO(s) + 2 HCl(aq)
2 NaHCO3(s)→
1 Na2CO3 + 1 CO2(g) + 1 H2O(g)
32.00 g O2 / 82.98 g Na3N / 132.1 g Ca(NO2)2 / 157.9 g P2O6/
1 mole O2 1 mole Na3N 1 mole Ca(NO2)2 1 mole P2O6
As another example, consider a solution of Na2SO4. As this molecule will break down into 2 Na+ ions and 1 SO42- ion (polyatomic ions act as a single ion), we see that each molecule of Na2SO4 breaks down into 3 ions.
1.4 M Na2SO4 x 3 ions = 4.2 Osm/L
Starting with 56 moles H2O and multiplying by 18.0 g H2O/mol H2O will give
1008 grams.
You can use molecular mass to convert from grams to moles. A 56.6 mole sample of methanol would have a molecular mass of
1813.46 g.
2 NaOH(aq) + 1 MgCl2(aq)→
2 NaCl(aq) + 1 Mg(OH)2(s)
2 molecules of H2 and one molecule of O2 react to form 2 molecules of H2O
2 mol of H2 and one mol of O2 react to form 2 mol of H2O
As another important example, consider a 2.5 M solution of CF4. Since C and F are both nonmetals, we would expect this molecular compound would not dissociate in water and instead stay as one piece. In other words, the Molarity and Osmolarity would be the same:
2.5 M CF4 x 1 molecule = 2.5 Osm/L
In Osmolarity, measured as Osm/L (Osmoles per liter), we show a more complete measurement of the amount of particles in solution by multiplying molarity by the number of ions formed per molecule. For example, If the molarity of a NaCl solution is 3 M, then we can determine osmolarity by multiplying this molarity by 2 (to account for the fact that each NaCl will break down into two ions: Na+ and Cl-):
3 M NaCl x 2 ions = 6 Osm/L.
3 MgSO4 + 2 Al(NO3)3 > 3 Mg(NO3)2 + Al2(SO4)3
3 Mg 3 3 S 3 30 O 30 2 Al 2 6 N 6
Convert 3.8 grams of H2O into moles (Molar mass of H2O is 18.02 g/mol)
3.8 g H2O * 1 mol H2O/ 18.02 g H2O = 0.21 moles H2O
1 C4H8(g) + 6 O2(g) →
4 CO2(g) + 4 H2O(l)
My water bottle contains 500 grams of water, H2O. How many moles of water is this?
500 grams of water, divided by 18.0 g/mol is 27.8 moles of water.
Avogadro's number:
6.022 x 1023
Convert 9.6 moles of NaOH into grams (Molar mass of NaOH is 40.0 g/mol)
9.6 mol NaOH * 40.0 g NaOH / 1 mol NaOH = 384 g NaOH
Solution
= Gas canister of oxygen and neon, Salt water, Bleach.
Which of the following would be considered a solution?
A solution consists of substances fully dissolved in other substances. Solutions also tend to be transparent. Table sugar in water is a solution.
Each of these terms describes a mixture based on factors such as particle size, composition, dispersal, and transparency.
Air= solution. Blood= colloid. Cream= emulsion. Flour in water= suspension.
mass by volume Be sure that your mass is in grams and your volume in in ml for % mass/volume.
Also, be sure to always multiply by 100 % as a final step.
Determine the % mass/mass concentration for a solution of 61 g of salt dissolved in 970 g of water.
Always remember to add up the total grams on the bottom for mass/mass % and be sure to multiply by 100% in the last step. The answer is 5.9%.
Mix two liquids together and shake them up. You see that you have microscopic droplets of one liquid suspended in the other. You would call this:
An emulsion is a type of suspension where microscopic droplets of one liquid are dispersed within another liquid.
The way to convert from g to mol OR mole to grams of a molecule is to use the molar mass of that molecule.
As you see, you can arrange the equation so that the unit you do not want cancels (grams O2) and you have the unit you want on top (moles O2). Molecular mass allows you to quickly convert between grams and moles
Which of the numbers represents the atomic mass of the atom below?
Atomic mass is the lower left number on the periodic table and has units of g/mole.
Balance the unbalanced chemical equation:
Balance the unbalanced chemical equation: 123456789 S8(g) + 101112131415 O2(g) → 123456789 SO3(g) Review FeedbackClose & Continue Your response is correct! Be sure to count up every atom on both the product and reactant side. A balanced equation is 1 S8(g) + 12 O2(g) → 8 SO3(g)
Sodium bromide reacts with calcium chloride to form sodium chloride and calcium bromide. Which of these chemical reactions represents the balanced reaction?
Balanced chemical equations have the same number of each atom on each side of the arrow. This equation is correct: 2 NaBr + CaCl2 → 2 NaCl + CaBr2 https://www.youtube.com/watch?v=7eSBigeIoE4
What would be the molarity of a solution made by dissolving 4.1 grams of NaCl (molecular mass: 58.44 g/mole) in water to a total volume of 0.4 liters 4.1/58.44/.4
Be sure to convert from grams to moles using the molecular mass. A common error is to use the molecular mass as the mole value, so be sure to avoid that. The answer is 0.18 M.
Balance the chemical equation:
Be sure to count all atoms on each side every time you change a coefficient. The balanced equation would be 1 C5H12 + 8 O2 → 6 H2O + 5 CO2
What is the Osmolarity of a 0.7 M KNO3 solution?
Be sure to review our polyatomic ions. Since we know that each KNO3 molecule will break down into K+ and NO3-, we see that each molecule breaks down into two ions. By multiplying number of ions with our molarity, we find our osmolarity. The answer is 1.4 Osm/L.
A particular solution for administering glucose to patients with low glucose levels is 10% mass/volume glucose in water. Which of the following preparations would give a glucose solution with this concentration? Select all that apply.
Be sure to take the total mass of the solution into account. The correct answers are 10 g of glucose mixed with 100 grams of water and 5 g of glucose mixed with 50 grams of water; % mass by volume is determined by: mass (g) / volume (ml) x 100%.
If I have 82 ml of a solution with a molarity of 5.3 M NaBr, how many ml of a 1.1 M NaBr solution can I prepare?Great work
Be sure to use the dilution equation when the situation calls for dilution. You can tell that dilution is needed here because we are going from a more concentrated solution to a less concentrated solution. The answer is 395.1 ml. c1v1=c2v2
Emulsion=
Butter, Homogenized milk.
The dilution formula is: (Concentration of what you have) x (Volume of what you have) = (Concentration of what you want) x (Volume of what you want)
C1V1=C2V2
What is the mass/volume % concentration of a solution that consists of 5 grams of sugar dissolved in a solution with a volume of 140 ml?
Calculating mass/volume % is similar to how we determine our % grade on a test. The answer is 5 grams / 140 ml = 0.0357 = 3.57%.
Which of the following chemical equations violates the Law of Conservation of Mass?
Check each chemical reaction to determine the one that does not have the same number of each atom on each side of the chemical reaction. If a chemical equation violates the Law of Conservation of Mass, the atoms will not equal out on both sides. The correct answer is 2 H2 + N2 → 2 NH3. There are four atoms of H on the left, or reactant side while there are six atoms of H on the right, or products side. As matter cannot be create or destroyed in a chemical reaction, these are not this choice violates the Law of Conservation of Mass.
4 Fe(s) + 3 O2(g) > 2 Fe2O3(s) Question 1 / 2 In the equation, how many molecules of O2 are in the chemical equation?
Coefficients show us how many molecules of a given compound are in a chemical equation. In this case there are 3 O2 molecules.
Colloid
Contains particles large enough to scatter light, and appear cloudy. Can be separated by a membrane but not by settling out. Often have gel like consistencies. Silica nanoparticles in water, Blood
A baby weighs 4 Kg. The pediatrician orders the nurse to administer 1.4 mg of the medication per Kg of the child's weight. The medication comes in a 5 mL vial that contains 10 mg of the medication. How many mL should the nurse administer to the baby?
Convert kg to mg, and then mg to liters. Look in the word problem for the conversion factors.
Heterogeneous mixtures are not uniform in their composition.
For example, a glass of soda would contain many bubbles of gas distributed unevenly through the mixture.
Given the following balanced equation, determine how many moles of HCl will be produced from 4.2 moles of HOCl? 3 HOCl → HClO3 + 2 HCl
Given 4.2 moles of HOCl and the mole-mole ratio from the balanced equation of 3 moles of HOCl = 2 moles HCl, multiply 4.2 moles HOCL by 2 moles HCl and divide by 3 moles HOCl to determine the answer: 2.8 moles HCl.
Not balanced as written
H2 + O2 > H2O K + O2 > K2O
Balanced as written
H2 + O2 > H2O2 Na + Cl > NaCl
Suspension
Heterogeneous nature. Cloudy dispersion of large particles (large enough to be seen with the naked eye). Particles often settle out over time. Muddy water, Fog
In contrast, homogenous mixtures are uniform in their composition. An example of a homogenous mixture is a glass of clear salt water, as the salt is dissolved completely and present uniformly all through the glass.
Homogenous mixtures that do not separate out over time and cannot be separated by most membranes are known as solutions.
If you were to dissolve 2.5 grams of NaCl in 150 g of water, You would call the NaCl the:
In a solution, the solute is the small part that is dissolved and the solvent is what the solute is dissolved in.
A mixture is a combination of more than one compound, physically mixed together (as opposed to reacting together chemically).
In other words, a mixture could be physically separated. For example, with our cup of tea, we could evaporate the water, leaving us with the tea leaf based compounds.
If you have 0.5 moles of NaCl, how many molecules of NaCl do you have?
Just as 12 makes a dozen, Avogadro's number (6.022 x 1023) makes a mole. So, just like half of a dozen is 6, half of a mole is half of Avogadro's number, 3.011 x 1023
If the balanced chemical reaction for the formation of Li2O is 4 Li(s) + O2(g) → 2 Li2O(s), how many molecules of Li2O(s) would you produce if you used up 6 atoms of Li(s)?
Just like following a recipe, we can know how many of an ingredient (reactant) we need to make a specified amount of product according to a recipe (balanced chemical equation). You produce 3 molecules of Li2O(s) by using 6 atoms of Li(s).
if we had 2 moles of CaCl2 in 4 liters of solution we would see that: for example, if we had 2 moles of CaCl2 in 4 liters of solution we would see that:
M= 2molCacl2/4L= .5 M Cacl2
Use g/mol as the unit for molecular mass and make sure to count up all atoms in each molecule.
MgCl2 Number of Mg atoms: 1 Number of Cl atoms: 2 Molecular Mass of MgCl2: 95.21 g/mole Ca(OH)2 Number of Ca atoms1Number of O atoms: 2 Number of H atoms: 2 Molecular Mass of Ca(OH)2: 74.1 g/mol (NH4)2S Number of N atoms: 2 Number of H atoms: 8 Number of S atoms: 1 Molecular Mass of (NH4)2S: 68.17 g/mol
What is the molarity of a solution that consists of 8.50 moles of HCl dissolved in 670.0 ml of solution?
Molarity is a way to express the amount of moles of a substance per liter. The answer is 12.7 M. 8.5m/.67l
Match the unit to the measurement.
Molecular weight has units of g/mol. Mass has units of grams. The balanced chemical equation has units of moles.
Emulsion
One liquid suspended, but not dissolved in another liquid. Often one liquid is water based and the other is oil based. Homogeneous mixture of oil and water, milk
Balance the following equation:
One mole of C2H8 will react with 4 moles of O2 to yield 2 moles of CO2 and 4 moles of H2O.
The osmolarity of a 1 M NaCl solution would be:
Osmolarity is molarity multiplied by the number of ions the dissolved solute breaks into in solution. Since each NaCl breaks down into a Na+ and a Cl-, we multiply 1 M by 2 ions to get 2 Osm/L.
What is the molecular mass of Mg(NO2)2?
Remember, molecular mass always has units of g/mole and we want to be sure to count every atom. The molecular mass of Mg(NO2)2 is 116.31 g/mol.
Solution
Solute particles cannot be visually distinguished from solvent or one another. Cannot be separated by a membrane or by settling out. Usually transparent. CaCl2 dissolved in water, Copper sulfate dissolved in water
I dissolve 1 gram of salt in 400 ml of hot water. I would call the resulting mixture a:
Solutions are typically transparent and have solutions have a solute completely dissolved in a solvent. Dissolving salt in water results in a solution.
The key to osmolarity is determine how many ions a compound will break down into and multiplying by the molarity. Be sure that you break down ionic compounds into ions while keeping covalently bound molecules attached.
The answers are: 6.8 M CaCl2= 20.4 Osm/L. 2.4 M PF3= 2.4 Osm/L. 3.0 M Na3PO3= 12.0 Osm/L.
4 Fe(s) + 3 O2(g) > 2 Fe2O3(s) How many total atoms of O are on the left side of the equation?
The coefficients tell us how many of a molecule we have, and subscripts show how many atoms are in each molecule. This means that by multiplying the coefficient by the number of atoms of a given element in a molecule, we can determine how many atoms of that element. In this case there are 3 x 2 = 6 oxygen atoms.
Mg3N2 + 6 NaBr → 3 MgBr2 + 2 Na3N
The coefficients tell you the relationships between the compounds in this chemical formula. Additionally, you could read this formula as: one mole of Mg3N2 reacts with six moles of NaBr to produce three moles of MgBr2 and two moles of Na3N.
In the unbalanced chemical equation Fe2O3(s) + HNO3(aq) → Fe(NO3)3(aq) + H2O(l), how many oxygen atoms are on the product side of the reaction?
The first step of balancing a chemical equation is to find how many atoms of each element are on each side of a chemical reaction. Be sure to count up all atoms in each term for both products and reactants separately. Oxygen has 10 atoms on the product side of this equation.
important gas solution
The gas used for anesthesia is typically a 50/50 mixture of N2O and O2. Commonly known as "laughing gas"
Given the following balanced equation, determine how many moles of O2 are needed to completely react with 8 moles of K: 4K + O2 > 2K2O
The mole-mole ratio between O2 and K is 1 mol O2 = 4 moles K, so starting with 8.0 moles of K will yield 2 moles of O2.
What is the molecular mass of Ca3(PO4)2?
The molecular mass of Ca3(PO4)2 is 310.2 g/mol.
Which of the following would you expect to have the greatest concentration?
The more solute in a given amount of solvent, the more concentrated the solution. In this case, the greatest concentration would have 6 grams of solute in 2 liters of solvent.
I took 20 ml of a 7 % NaCl solution and added water to bring the total volume of the solution to 100 ml. The resulting solution has a concentration of 1.4 %. This process is known as:
The process of taking a concentrated solution and making the solution less concentrated is known as dilution.
If 20 ml of ethanol is mixed with 100 ml of water, the ethanol would be considered the:
The solute is the small portion and the solvent is the major portion of the solution. Therefore, ethanol would be considered the solute.
The coefficients represent the number of molecules.
The subscripts in a formula represent the number of atoms.
In the following chemical equation, which of the compounds are dissolved in water? Select all that apply AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
The symbols after the molecule indicate the state of matter. (aq) indicates aqueous compounds, so AgNO3, NaCl, and NaNO3 are all dissolved in water.
The units of mass are grams, which can be measured easily in a lab or similar. The units of moles are used in balanced chemical equations.
Therefore, the molar mass from the periodic table can be used to relate what is measured in lab to what is written in balanced chemical equations.
This means that you can say that the coefficients in a chemical equation represent the number of moles.
This allows us to do mole to mole conversions.
The coefficients show the number of molecules of a given compound
This equation is 2 H2(g) + 1 O2(g) > 2 H2O(g)
Assuming the tea leaves were removed, the composition of the tea in the cup would be uniform.
This tea would therefore be considered a homogenous mixture we call a solution.
Suspension=
Urine sample with visible particles.
Using the chemical formula CaO + 2 NaCl → Na2O + CaCl2, calculate how many moles of CaCl2 you would produce if you used up 5.4 moles of CaO?
Using the chemical formula CaO + 2 NaCl → Na2O + CaCl2, calculate how many moles of CaCl2 you would produce if you used up 5.4 moles of CaO? 5.4 moles CaO * 1 mole CaCl2 / 1mole CaO = 5.4 mole CaCl2
What is the molarity of a solution prepared by dissolving 6.0 grams of NaOH (molecular mass = 40.0 g/mol) to a total volume of 300 ml.
We must always be sure that our amount of compound is in moles and our volume is in liters to calculate molarity. The way to convert from grams to moles is to use the molar mass from the periodic table. Be sure also to convert your volume to liters. The answer is 0.5 M NaOH.
Select all examples where the Law of Conservation of Mass is not being followed.
When both sides of a chemical equation have the same number of each atom, the Law of conservation of mass is followed and the equation is balanced. Otherwise, the equation is unbalanced. The equations S8(g) + Ag(s) → 8 AgS and Mg3N2(s) + 3 H2O(l) → NH3(g) + 3 Mg(OH)2(s) are both unbalanced.
What is the % mass/mass of a methanol solution prepared by mixing 70 grams of ethanol and 800 grams of water?
When determinizing solution concentration by looking at % by mass/mass, be sure that you add up the total mass of solution on the bottom. Also, be sure to always multiply by 100 %. The answer is 8.05%. 70/(70=800)*(100)%
Colloid=
Whole blood, Proteins in blood.
Use the reaction below to determine how many moles of Al2S3 you would produce from fully reacting 15 moles of Ag2S: 3 Ag2S + 2 Al → 6 Ag + Al2S3
You can perform mole to mole conversions using the ratios from a balanced chemical equation. Make sure that your units cancel. In this reaction you would produce 5 moles of Al2S3
3 CaCl2(aq) + 2 Na3PO4(aq) → Ca3(PO4)2(s) + 6 NaCl(aq) If you have 17 grams of NaCl, how many moles of NaCl do you have?
You would have 0.29 moles of NaCl.
3 CaCl2(aq) + 2 Na3PO4(aq) → Ca3(PO4)2(s) + 6 NaCl(aq) If you produced 5 moles of Ca3(PO4)2, how many moles of NaCl did you also produce?
You would produce 30 moles of NaCl.
Using the chemical formula 2 H2O → 2 H2 + O2, calculate how many moles of O2 you could produce from 42 mols of H2O
Your response is correct! 42 moles H2O * 1 mole O2/2 moles H2O = 21 moles O2
Solution:
a homogenous mixture of two or more substances; components cannot be distinguished visually from one another
The units you use here for atomic mass will be:
g/mol (grams per mole).
The molar mass from the periodic table has units of
grams per mole (g/mol).
balance the equation 2 H2 + 1 O2 →
https://www.webqc.org/balance.php 2 H2O
Reactants are on the left side of the arrow
products are on the right side of the arrow.
Solvent:
the substance that makes up the larger part of the solution
Solute:
the substance that makes up the smaller part of the solution
