Questions from Exam Grade 11 Just Check

[Raza]

Hi, my exam is coming pretty soon and I looked at last year's exam and found numerous questions that I don't know. Could someone please check my answers listed below.

A solution of any type is different from a compound because:
(A) a compound is always coloured, solutions never are.
(B) there is more than one phase in a compound.
(C) a solution contains more than one element.
(D) the composition of a compound is fixed and a solution isn’t.
(E) the solution is the same in every way as the compound.

The oxides of nonmetals, when dissolved in water, generally form: *I don't even know what is oxides are
(A) acids.
(B) carbonates.
(C) salts.
(D) bicarbonates.
(E) bases. *I think oxides means oxygen. O+H= base

An orbital is best described as:
(A) a cloud with hundreds of electrons in it.
(B) a cloud holding a maximum of 1e-.
(C) a cloud which is always perfectly circular.
(D) a region in space where there is a high probability of finding the electron.
(E) the spherical path followed by the electron.

Which of the following exhibits the greatest ionic character?
(A) RbF
(B) Al2O3
(C) CO2
(D) NH3
(E) IF

An oxy-acid is a compound which: * I have no idea but I guess...
(A) contains only metal and oxygen.
(B) contains at least three elements.
(C) does not contain hydrogen.
(D) is a binary compound.
(E) is usually a basic compound.

Which of the following statements about bonding is FALSE?
(A) The attractive forces are greater than the repulsive forces.
(B) A single covalent bond always has 2e-.
(C) A lowering of energy results when bonds form.
(D) The molecules formed are more stable that the individual atoms.
(E) Bonding occurs only when equal sharing of electrons occurs.

Which of the following substances, when dissolved in water, is a non-electrolyte? *Is there a way to find out which one is electrolyte??
(A) NaCl
(B) HNO3
(C) Cu2SO4
(D) C12H6O12
(E) MgBr2


If it is incorrect, please explain it to me why.
Thank YOU

 

[Gokul43201]

A solution of any type is different from a compound because:
(A) a compound is always coloured, solutions never are.
(B) there is more than one phase in a compound.
(C) a solution contains more than one element.
(D) the composition of a compound is fixed and a solution isn’t.
(E) the solution is the same in every way as the compound.

Correct.

The oxides of nonmetals, when dissolved in water, generally form: *I don't even know what is oxides are
(A) acids.
(B) carbonates.
(C) salts.
(D) bicarbonates.
(E) bases. *I think oxides means oxygen. O+H= base

Wrong. Check your text or Google "non-metallic oxide".

An orbital is best described as:
(A) a cloud with hundreds of electrons in it.
(B) a cloud holding a maximum of 1e-.
(C) a cloud which is always perfectly circular.
(D) a region in space where there is a high probability of finding the electron.
(E) the spherical path followed by the electron.

Correct.

Which of the following exhibits the greatest ionic character?
(A) RbF
(B) Al2O3
(C) CO2
(D) NH3
(E) IF

Incorrect. What determines ionic character ?

An oxy-acid is a compound which: * I have no idea but I guess...
(A) contains only metal and oxygen.
(B) contains at least three elements.
(C) does not contain hydrogen.
(D) is a binary compound.
(E) is usually a basic compound.

Incorrect. GOOGLE ?

Which of the following statements about bonding is FALSE?
(A) The attractive forces are greater than the repulsive forces.
(B) A single covalent bond always has 2e-.
(C) A lowering of energy results when bonds form.
(D) The molecules formed are more stable that the individual atoms.
(E) Bonding occurs only when equal sharing of electrons occurs.

Incorrect. Can you show an example of a single covalent bond that does not have 2 e-s ? This is a bad question because there are actually two FALSE statements. Whoever set this question does not realize that the first statement(A) is also false, but that is not the "required" answer.

Which of the following substances, when dissolved in water, is a non-electrolyte? *Is there a way to find out which one is electrolyte??
(A) NaCl
(B) HNO3
(C) Cu2SO4
(D) C12H6O12
(E) MgBr2

What is an electrolyte ? What must something have, to be an electrolyte ?
[/QUOTE]

 

[ravenprp]

Hi there, it's great that you are taking the initiative to study and prepare for your exam! I'll do my best to help you with these questions.

Firstly, the answer to the first question is (D) the composition of a compound is fixed and a solution isn’t. This is because compounds are made up of specific elements in a fixed ratio, while solutions can vary in their composition depending on the amount of solute (substance being dissolved) and solvent (substance doing the dissolving).

For the second question, oxides are compounds made up of oxygen and another element. When dissolved in water, they can form acids, bases, or salts depending on the specific oxide and the strength of the solution. So the answer is (A) acids.

An orbital is a region in space where there is a high probability of finding an electron. So the best answer is (D) a region in space where there is a high probability of finding the electron.

The answer to the question about ionic character is (A) RbF. Ionic character refers to the degree of difference in electronegativity (ability to attract electrons) between two atoms in a bond. RbF has the largest electronegativity difference between the two atoms, making it the most ionic.

An oxy-acid is a compound that contains oxygen, hydrogen, and at least one other element. So the answer is (B) contains at least three elements.

The false statement about bonding is (E) bonding occurs only when equal sharing of electrons occurs. Bonding can occur through different types of interactions, such as ionic, covalent, and metallic, and does not necessarily involve equal sharing of electrons.

To determine which substance is a non-electrolyte, you can look at the chemical formula and determine if it dissociates (breaks apart) into ions in water. If it does, it is an electrolyte. If it does not, it is a non-electrolyte. So the answer is (D) C12H6O12.

I hope this helps you better understand these concepts and prepares you for your exam. Remember to always check your answers and ask for clarification if needed. Good luck!