Why Is Sodium Carbonate Be Very Soluble In Water
Unit 4: Solutions and Solubility
Lesson 13 Key Questions:
42. a) Cloudy pond water – Heterogenous, light cannot pass though, can see different parts.
b) Apple Juice – Solution, organic apple particles(solute), and water(solvent).
c) Rainwater – Solution, CO2, hydrogen(solute), and water(solvent).
d) 14-karat gold in jewelry – Heterogenous, light cannot pass through. Just because light can’t pass through, doesn’t mean it’s not a solution! Gold is a solid solution – it is different metals mixed together, but when you observe it, only one phase is visible.
(1 mark lost)
43. Sodium Carbonate will be very soluble in water because of the positive ions of sodium attached to the negative ions of the carbonate. Methanol will be partly soluble in water due to it’s small size and the presence of the OH group in the molecule and it’s very polar nature. Gasoline (Octane), is completely insoluble since it is non-polar. …show more content…
(1 mark lost)
44.
a) Sodium Carbonate: Na2CO3 CO2 + Na2O
b) Magnesium Chloride: 2MgCl2 Mg2 + 4Cl
c)Ammonium Hydroxide: NH4OH H2O + NH3
You did not show any ionic charges on the products. All of these compounds are ionic compounds they will simply separate into the ions, there will be no new molecules made, as you have indicated in parts and c. Lastly, for B, there was no need to add 2 as a coefficient Mg is a metal, it does not exist as a diatomic molecule.
(4 marks lost)
45. Both covalent and ionic substances allow water to surround it, and hydrate the substance. It is just that eventually the water breaks apart ionic substances, and covalent substances just continue to be hydrated without dissociating. Ok, but why does water surround the particles? How do the particles become spread out in the solution?
(2 marks
lost)
46. Water is a universal solvent because it is polar, with a positive end, and a negative end, giving H2O it’s ability to easily dissociate and dissolve most other compounds. When mixed with another substance, H2O’s differently charged side attach to the other compound’s charged ions/polar sites, surround them, and then starts to separate all the ions from each other, breaking apart the compound, and ‘dissolving’ it. Yes, polarity plays a big part –> but what are the attractive forces called that are due to the polarity of the molecules? Also, how does water’s size play a factor?
(1.5 marks lost)
Lesson 14 Key Questions:
47. a) Precipitate will be Ba3(PO4)2 + 6NH4OH correct
b) No precipitate.
c) No precipitate.
Both b and c will form a precipitate.
(2 marks lost)
48. a) 3Ba(OH)2 + 2(NH4)3PO4 Ba3(PO4)2 + 6NH4OH
Where is the total ionic equation?
3Ba + 2PO4 Ba3(PO4)2(s)
Your ions need proper charges.
(1.5 mark lost)
b) AgNO3+ KCH3CO2 AgCH3CO2+ KNO3 No reaction occurs
c) Cu2SO4 + 2NaClL 2CuCl + Na2SO4 No reaction occurs
Both b and c, reactions will occur.
(4 marks lost)
49. Using a precipitation reaction test, it can be determined whether a solution has acetate or carbonate present in it. Carbonate is insoluble in water, so most likely it would be easier to separate from the solution. Carbonate is an ion. It is soluble when combined with some compounds, and insoluble when combined with others. By adding a substance that causes carbonate to precipitate, it can be determined whether the ion that is present is carbonate or acetate, since acetate is soluble in water. ???
It is obvious that this concept confuses you. You need to review the content, and ask any specific questions. They can be sent to teacher@tvo.com, or through other methods.
(4 marks lost)
50. If there is a substance in the water that is unwanted and needs to be removed, another substance that causes it to precipitate can be added in excess to the water supply, to completely remove the unwanted substance by precipitation. Once that is completed and the unwanted substance is completely absent from the water, the remaining substance that was added in excess can then be removed by some other form of treatment. There is a process for removing unwanted particles from water – what are the stages called? What you suggest would not be a very safe way to treat water, and would be very expensive, since such large amounts of chemicals would be used. If we can’t use this method to CLEAN the water, how else can it be utilized in water treatment?
(1.5 marks lost)
51. a) Bottled Water in My Municipality
Benefits
Challenges
-more efficient (can carry around)
-can purchase almost anywhere
-tap water is tested more often
-colossal environmental damage good b) Bottled Water in a Developing Country
Benefits
Challenges
-Safer than their surrounding water
-Easy to carry around (containers)
-Expensive
-Creates harmful waste good Lesson 15 Key Questions:
52. Percent by volume = 30.0 x 100% divided by 600 = 5% concentration.
This answer does not have enough significant digits. How do you show it is % by volume?
(0.5 mark lost)
53. 35.5 divided by 84.01 = 0.423 units?
0.423 divided by 4.50 =0.94M NaHCO3 is the molar concentration
This answer does not have enough significant digits.
(0.5 mark lost)
54. 0.500 x 0.15L = 8.50 x v2
0.500 x 0.15 divided by 8.50 = 0.00882L or 8.82mL volume of concentrated ammonium hydroxide is required.
This answer has too many significant digits.
(0.5 mark lost)
55. a) First, using the dilution formula, calculate the volume of first solution required.
b) Second, using a correctly sized measuring item, measure out the 8.83mL of ammonium hydroxide solution. You need to specify what to use to measure.
(1 mark lost)
c) Add 75mL of distilled water to a volumetric flask, and then add the measured 8.82mL of ammonium hydroxide.
d) Rinse the container with distilled water a few times and pour into the volumetric flask, and add enough water to reach the 150mL mark on the flask. Then mix. ok
56. Adding water to a container of concentrated substance may cause friction and energy to occur and start a reaction that might be dangerous. Friction is not an issue, and the reaction could be dangerous no matter which order they are added in. So adding solute to water instead, adds to solute slowly in smaller doses rather than all at once. It can be dangerous, but you have not properly explained why.
(1 mark lost)
57. 3CuCl2 + 2Al 2AlCl3 + 3Cu
5.5g divided by 27g this value is not accurate enough. = 0.203mol
0.304mol of CuCl2 needed.
0.304 divided by 0.125 = 2.43L CuCl2 volume needed to react completely. ok 58. NaC2H3O2 + AgNO3 NaNO3 + AgC2H3O2
0.2 x 0.5 = 0.1mols NaC2H3O2
0.4 x 0.2 = 0.8mols AgNO3 Incorrect you used the wrong initial values.
AgNO3 is limiting.
You know the number of moles of reactant used, you need to determine the number of moles of product before converting to mass.
(1 mark lost)
0.08 x 166.9 = 13.35g ppt collected. Value is incorrect due to above mistake, but the process is correct. This answer has too many significant digits.
%Yield 13.8 divided by 13.35 x 100% = 103.4% percent yield.
This answer has too many significant digits.
(0.5 mark lost)
Lesson 16 Key Questions:
59. The Arrhenius Theory is that when acids are placed into water, they ionize to release a hydrogen ion, while bases dissociate and dissolve when introduced to water. Although a free hydrogen ion is now released into the substance, it will not stay unattached so it will combine with a water molecule, creating a hydronium ion. You did not include a reaction as asked.
(1 mark lost)
60. Nitric acid is much stronger than nitrous acid (pH less than 1 vs. 4), therefore it dissociates in a liquid solution easier and faster than nitrous acid. Since it dissociates faster, it can produce more hydrogen ions, creating more electricity, meaning that the light bulb would light up more since there is more electricity being created with nitric acid.
So are they both strong, weak, or one of each? You said they were different, but did not specify HOW eg, what happens in a weak acid? You need to be more specific in your answers.
(1.5 marks lost)
61. 2HCl + Ca(OH)2 CaCl2 + 2H2O
2.68 divided by 74.09 = 0.036mol x 2 = 0.072mol HCl You should not do multiple steps in one line. The first statement is NOT equal to the last value.
0.072 divided by 0.1 = 0.72L or 720mL volume of stomach acid could be neutralized.
This answer does not have enough significant digits.
(0.5 mark lost)
62. Trial 1: 25.30mL – 0.00mL =?
Trial 2: 50.51mL – 25.30mL = 25.21mL
Trial 3: 75.89mL – 50.51mL = 25.38mL
KOH volume = (25.30 + 25.21 + 25.38) divided by 3 = 25.30mL
Reaction equation?
(1 mark lost)
3.00 x 10-4mol divided by L x 0.02530L = 7.59 x 10-4mol This calculates moles of what? pH= -(-4.52) = 4.52 pHh Incorrect.
There are a couple problems with this. You cannot go from moles to pH there are more steps! Your first calculation is NOT H+ ions.
(3 marks lost)
Total mark 46.5/81 = 57%
Lesson 13 Key Questions:
42. a) Cloudy pond water – Heterogenous, light cannot pass though, can see different parts.
b) Apple Juice – Solution, organic apple particles(solute), and water(solvent).
c) Rainwater – Solution, CO2, hydrogen(solute), and water(solvent).
d) 14-karat gold in jewelry – Heterogenous, light cannot pass through. Just because light can’t pass through, doesn’t mean it’s not a solution! Gold is a solid solution – it is different metals mixed together, but when you observe it, only one phase is visible.
(1 mark lost)
43. Sodium Carbonate will be very soluble in water because of the positive ions of sodium attached to the negative ions of the carbonate. Methanol will be partly soluble in water due to it’s small size and the presence of the OH group in the molecule and it’s very polar nature. Gasoline (Octane), is completely insoluble since it is non-polar. …show more content…
(1 mark lost)
44.
a) Sodium Carbonate: Na2CO3 CO2 + Na2O
b) Magnesium Chloride: 2MgCl2 Mg2 + 4Cl
c)Ammonium Hydroxide: NH4OH H2O + NH3
You did not show any ionic charges on the products. All of these compounds are ionic compounds they will simply separate into the ions, there will be no new molecules made, as you have indicated in parts and c. Lastly, for B, there was no need to add 2 as a coefficient Mg is a metal, it does not exist as a diatomic molecule.
(4 marks lost)
45. Both covalent and ionic substances allow water to surround it, and hydrate the substance. It is just that eventually the water breaks apart ionic substances, and covalent substances just continue to be hydrated without dissociating. Ok, but why does water surround the particles? How do the particles become spread out in the solution?
(2 marks
lost)
46. Water is a universal solvent because it is polar, with a positive end, and a negative end, giving H2O it’s ability to easily dissociate and dissolve most other compounds. When mixed with another substance, H2O’s differently charged side attach to the other compound’s charged ions/polar sites, surround them, and then starts to separate all the ions from each other, breaking apart the compound, and ‘dissolving’ it. Yes, polarity plays a big part –> but what are the attractive forces called that are due to the polarity of the molecules? Also, how does water’s size play a factor?
(1.5 marks lost)
Lesson 14 Key Questions:
47. a) Precipitate will be Ba3(PO4)2 + 6NH4OH correct
b) No precipitate.
c) No precipitate.
Both b and c will form a precipitate.
(2 marks lost)
48. a) 3Ba(OH)2 + 2(NH4)3PO4 Ba3(PO4)2 + 6NH4OH
Where is the total ionic equation?
3Ba + 2PO4 Ba3(PO4)2(s)
Your ions need proper charges.
(1.5 mark lost)
b) AgNO3+ KCH3CO2 AgCH3CO2+ KNO3 No reaction occurs
c) Cu2SO4 + 2NaClL 2CuCl + Na2SO4 No reaction occurs
Both b and c, reactions will occur.
(4 marks lost)
49. Using a precipitation reaction test, it can be determined whether a solution has acetate or carbonate present in it. Carbonate is insoluble in water, so most likely it would be easier to separate from the solution. Carbonate is an ion. It is soluble when combined with some compounds, and insoluble when combined with others. By adding a substance that causes carbonate to precipitate, it can be determined whether the ion that is present is carbonate or acetate, since acetate is soluble in water. ???
It is obvious that this concept confuses you. You need to review the content, and ask any specific questions. They can be sent to teacher@tvo.com, or through other methods.
(4 marks lost)
50. If there is a substance in the water that is unwanted and needs to be removed, another substance that causes it to precipitate can be added in excess to the water supply, to completely remove the unwanted substance by precipitation. Once that is completed and the unwanted substance is completely absent from the water, the remaining substance that was added in excess can then be removed by some other form of treatment. There is a process for removing unwanted particles from water – what are the stages called? What you suggest would not be a very safe way to treat water, and would be very expensive, since such large amounts of chemicals would be used. If we can’t use this method to CLEAN the water, how else can it be utilized in water treatment?
(1.5 marks lost)
51. a) Bottled Water in My Municipality
Benefits
Challenges
-more efficient (can carry around)
-can purchase almost anywhere
-tap water is tested more often
-colossal environmental damage good b) Bottled Water in a Developing Country
Benefits
Challenges
-Safer than their surrounding water
-Easy to carry around (containers)
-Expensive
-Creates harmful waste good Lesson 15 Key Questions:
52. Percent by volume = 30.0 x 100% divided by 600 = 5% concentration.
This answer does not have enough significant digits. How do you show it is % by volume?
(0.5 mark lost)
53. 35.5 divided by 84.01 = 0.423 units?
0.423 divided by 4.50 =0.94M NaHCO3 is the molar concentration
This answer does not have enough significant digits.
(0.5 mark lost)
54. 0.500 x 0.15L = 8.50 x v2
0.500 x 0.15 divided by 8.50 = 0.00882L or 8.82mL volume of concentrated ammonium hydroxide is required.
This answer has too many significant digits.
(0.5 mark lost)
55. a) First, using the dilution formula, calculate the volume of first solution required.
b) Second, using a correctly sized measuring item, measure out the 8.83mL of ammonium hydroxide solution. You need to specify what to use to measure.
(1 mark lost)
c) Add 75mL of distilled water to a volumetric flask, and then add the measured 8.82mL of ammonium hydroxide.
d) Rinse the container with distilled water a few times and pour into the volumetric flask, and add enough water to reach the 150mL mark on the flask. Then mix. ok
56. Adding water to a container of concentrated substance may cause friction and energy to occur and start a reaction that might be dangerous. Friction is not an issue, and the reaction could be dangerous no matter which order they are added in. So adding solute to water instead, adds to solute slowly in smaller doses rather than all at once. It can be dangerous, but you have not properly explained why.
(1 mark lost)
57. 3CuCl2 + 2Al 2AlCl3 + 3Cu
5.5g divided by 27g this value is not accurate enough. = 0.203mol
0.304mol of CuCl2 needed.
0.304 divided by 0.125 = 2.43L CuCl2 volume needed to react completely. ok 58. NaC2H3O2 + AgNO3 NaNO3 + AgC2H3O2
0.2 x 0.5 = 0.1mols NaC2H3O2
0.4 x 0.2 = 0.8mols AgNO3 Incorrect you used the wrong initial values.
AgNO3 is limiting.
You know the number of moles of reactant used, you need to determine the number of moles of product before converting to mass.
(1 mark lost)
0.08 x 166.9 = 13.35g ppt collected. Value is incorrect due to above mistake, but the process is correct. This answer has too many significant digits.
%Yield 13.8 divided by 13.35 x 100% = 103.4% percent yield.
This answer has too many significant digits.
(0.5 mark lost)
Lesson 16 Key Questions:
59. The Arrhenius Theory is that when acids are placed into water, they ionize to release a hydrogen ion, while bases dissociate and dissolve when introduced to water. Although a free hydrogen ion is now released into the substance, it will not stay unattached so it will combine with a water molecule, creating a hydronium ion. You did not include a reaction as asked.
(1 mark lost)
60. Nitric acid is much stronger than nitrous acid (pH less than 1 vs. 4), therefore it dissociates in a liquid solution easier and faster than nitrous acid. Since it dissociates faster, it can produce more hydrogen ions, creating more electricity, meaning that the light bulb would light up more since there is more electricity being created with nitric acid.
So are they both strong, weak, or one of each? You said they were different, but did not specify HOW eg, what happens in a weak acid? You need to be more specific in your answers.
(1.5 marks lost)
61. 2HCl + Ca(OH)2 CaCl2 + 2H2O
2.68 divided by 74.09 = 0.036mol x 2 = 0.072mol HCl You should not do multiple steps in one line. The first statement is NOT equal to the last value.
0.072 divided by 0.1 = 0.72L or 720mL volume of stomach acid could be neutralized.
This answer does not have enough significant digits.
(0.5 mark lost)
62. Trial 1: 25.30mL – 0.00mL =?
Trial 2: 50.51mL – 25.30mL = 25.21mL
Trial 3: 75.89mL – 50.51mL = 25.38mL
KOH volume = (25.30 + 25.21 + 25.38) divided by 3 = 25.30mL
Reaction equation?
(1 mark lost)
3.00 x 10-4mol divided by L x 0.02530L = 7.59 x 10-4mol This calculates moles of what? pH= -(-4.52) = 4.52 pHh Incorrect.
There are a couple problems with this. You cannot go from moles to pH there are more steps! Your first calculation is NOT H+ ions.
(3 marks lost)
Total mark 46.5/81 = 57%