Can someone please help me? Are these questions correct...if not any suggestions would be greatly appreciated!
1. What salt forms as the result of a mixture of calcium hydroxide and hydrochloric acid?
a. CaCl
b. CaHCl
c. CaCl2
d. CaOH
e. Cl(OH)2
I believe this is C- CaCl2, is that right?
2. Which of the following is a salt?
a. HNO3
b. H2SO4
c. CaSO4
d. NaOH
e. NH3
I believe this is C- CaSO4, is that correct?
3. Which if the following is a strong electrolyte?
a. AgNO3
b. NH3
c. C2H3O2
d. C12H22O11
e. HF
I believe this is A- AgNO3, is that right?
4. Which of the following salts is insoluble?
a. LiCl
b. CuNO3
c. Ba(C2H3O2)2
d. NaI
e. CaSO4
I believe this is E- CaSO4, is that correct?
5. Which of the following is a soluble salt?
a. CaCO3
b. SrS
c. CaCl2
d. PbSO4
e. PbI2
I believe this is C- CaCl2, is that right?
Thanks for the help!
They look ok to me. The only question I would pose is for "solubility in what?" My presumption is that all of these questions that deal with solubility means solubility in water.
(b) Calculate the pH and pOH of a 0.01 moldm-3 ammonia solution given that Kb for ammonia is
1.8x10-5 moldm-3 (7 marks)
1. To determine the salt formed as a result of mixing calcium hydroxide and hydrochloric acid, you need to know the chemical formula of each compound and how they react with each other. Calcium hydroxide (Ca(OH)2) is a base, while hydrochloric acid (HCl) is an acid. When these two react, they undergo a neutralization reaction. The general equation for this reaction is:
Base + Acid → Salt + Water
In this case, the calcium hydroxide reacts with hydrochloric acid to form a salt and water. The chemical formula of the salt produced is determined by combining the cation (Ca2+) from the base and the anion (Cl-) from the acid. The charges must balance, so the calcium cation has a charge of +2 and the chloride anion has a charge of -1.
By combining these ions, the resulting salt is calcium chloride (CaCl2). Therefore, your answer is indeed correct - C. CaCl2.
2. To identify a salt among the options given, you need to understand what a salt is. In chemistry, a salt is a compound formed when an acid reacts with a base. It is composed of a cation and an anion. Looking at the options:
a. HNO3 - This is nitric acid, not a salt.
b. H2SO4 - This is sulfuric acid, not a salt.
c. CaSO4 - This is calcium sulfate, which is indeed a salt.
d. NaOH - This is sodium hydroxide, not a salt.
e. NH3 - This is ammonia, not a salt.
Therefore, your answer is correct - C. CaSO4.
3. To determine which of the compounds is a strong electrolyte, you need to understand the concept of electrolytes. Electrolytes are substances that dissociate into ions when dissolved in water, resulting in the solution conducting electricity.
Looking at the options:
a. AgNO3 - This is silver nitrate, and it dissociates into silver ions (Ag+) and nitrate ions (NO3-) when dissolved in water. It is a strong electrolyte.
b. NH3 - This is ammonia, and it does not dissociate into ions in water. It is not an electrolyte.
c. C2H3O2 - This is acetate, and it does not readily dissociate into ions in water. It is not an electrolyte.
d. C12H22O11 - This is sucrose, a sugar compound, and it does not dissociate into ions in water. It is not an electrolyte.
e. HF - This is hydrofluoric acid, and it partially dissociates into hydrogen ions (H+) and fluoride ions (F-) in water. It is a weak electrolyte.
Therefore, your answer is correct - A. AgNO3.
4. To determine which of the salts is insoluble, you need to understand the solubility rules for salts. These rules provide guidance on which salts are soluble and which are insoluble in water.
Looking at the options:
a. LiCl - Lithium chloride is soluble because all group 1A (alkali metal) salts are soluble.
b. CuNO3 - Copper nitrate is soluble because all nitrates are soluble.
c. Ba(C2H3O2)2 - Barium acetate is soluble because all acetates are soluble.
d. NaI - Sodium iodide is soluble because all iodides are soluble.
e. CaSO4 - Calcium sulfate is insoluble, based on the solubility rules. Sulfates are generally soluble, but calcium sulfate is an exception and is insoluble.
Therefore, your answer is correct - E. CaSO4.
5. To identify the soluble salt, you can again refer to the solubility rules for salts.
Looking at the options:
a. CaCO3 - Calcium carbonate is generally insoluble, based on the solubility rules.
b. SrS - Strontium sulfide is generally insoluble, based on the solubility rules.
c. CaCl2 - Calcium chloride is soluble because all chlorides (except those of silver, lead, and mercury) are soluble.
d. PbSO4 - Lead(II) sulfate is generally insoluble, based on the solubility rules.
e. PbI2 - Lead(II) iodide is generally insoluble, based on the solubility rules.
Therefore, your answer is correct - C. CaCl2.
I hope this helps clarify the explanations for each question! Let me know if you have any further questions.