S1T2:
Which of the following quantum numbers determine the energy of atomic orbitals in the hydrogen atom?
1: Principal quantum number; 2: Azimuthal quantum number; 3: Magnetic quantum number; 4: Spin quantum number
Which of the following quantum numbers determine the energy of atomic orbitals in the hydrogen atom?
1: Principal quantum number; 2: Azimuthal quantum number; 3: Magnetic quantum number; 4: Spin quantum number
Final Results
37%
A. 1 only
29%
B. 1 and 2 only
20%
C. 1, 2 and 3 only
15%
D. 1, 2, 3 and 4
❤1
S2:
An oxide of a Period 3 element dissolves in water to form the strongest acid among the acids formed by oxides of Period 3 elements. Which of the following is the element?
An oxide of a Period 3 element dissolves in water to form the strongest acid among the acids formed by oxides of Period 3 elements. Which of the following is the element?
Final Results
9%
A. Silicon
33%
B. Sulphur
46%
C. Chlorine
13%
D. Phosphorus
❤4
S2:
Which of the following statements is true about halogens and their compounds?
Which of the following statements is true about halogens and their compounds?
Final Results
16%
A. HF is the strongest hydrohalic acid.
36%
B. The bond energy of the F-F bond is the highest.
37%
C. KI is the strongest reducing agent among the KX compounds.
11%
D. Cl₂ is the most reactive halogen.
S1T2:
Atom X has an electronic configuration of 1s²2s²2p⁶3s²3p⁴. How many orbitals in atom X are filled with valence electrons?
Atom X has an electronic configuration of 1s²2s²2p⁶3s²3p⁴. How many orbitals in atom X are filled with valence electrons?
Final Results
30%
A. 2
28%
B. 3
36%
C. 4
6%
D. 5
S1T2:
Atom Y has an electronic configuration of 1s²2s²2p⁶3s²3p³. How many subshells in atom Y are filled with valence electrons?
Atom Y has an electronic configuration of 1s²2s²2p⁶3s²3p³. How many subshells in atom Y are filled with valence electrons?
Final Results
30%
A. 2
47%
B. 3
10%
C. 4
14%
D. 5
Good morning everyone.
Numerous teachers and students have PMed me, asking whether the atomisation of water refers to liquid water or gaseous water. My answer is very clear — it refers to liquid water, as that is the physical state of water under standard conditions (25 °C and 1.0 atm). The standard enthalpy change is defined based on internationally recognised conventions that are consistently applied.
However, if a question clearly states "atomisation of steam" or "water vapour," that would be a different story.
I hope this explanation clears up your doubts.
Lastly, let’s leave the past behind — we can't change it — and focus on S3, where we still have the power to influence the outcome.
All the best to you all. Thank you.
Numerous teachers and students have PMed me, asking whether the atomisation of water refers to liquid water or gaseous water. My answer is very clear — it refers to liquid water, as that is the physical state of water under standard conditions (25 °C and 1.0 atm). The standard enthalpy change is defined based on internationally recognised conventions that are consistently applied.
However, if a question clearly states "atomisation of steam" or "water vapour," that would be a different story.
I hope this explanation clears up your doubts.
Lastly, let’s leave the past behind — we can't change it — and focus on S3, where we still have the power to influence the outcome.
All the best to you all. Thank you.
👍18❤1
Pre-S3:
Which of the following is the general formula of cycloalkanes?
Which of the following is the general formula of cycloalkanes?
Final Results
32%
A. CₙH₂ₙ
20%
B. CₙH₂ₙ₊₁
36%
C. CₙH₂ₙ₊₂
12%
D. CₙH₂ₙ₋₂
Pre-S3:
How many sigma bonds are there in a propene molecule?
How many sigma bonds are there in a propene molecule?
Final Results
34%
A. 8
11%
B. 7
26%
C. 6
29%
D. 2
Pre-S3:
Which of the following statements best describes arenes?
Which of the following statements best describes arenes?
Final Results
35%
A. Compounds with at least one C=C bond and a benzene ring.
39%
B. Organic compounds with an aromatic ring structure.
9%
C. Organic compounds with a cyclic structure.
17%
D. Hydrocarbons with benzene ring.
S1T3:
Which of the following statements is true about the CH₃NH₂ molecule?
Which of the following statements is true about the CH₃NH₂ molecule?
Final Results
38%
A. It has one sp³ hybridised atom.
33%
B. There is a dative bond in the molecule.
4%
C. All atoms in the molecule lie in the same plane.
24%
D. It is a covalent compound which is soluble in water.
S1T3:
Which of the following statements is NOT true about CH₃NH₃Cl?
Which of the following statements is NOT true about CH₃NH₃Cl?
Final Results
33%
A. It’s an ionic compound with a tetrahedrally centered cation.
18%
B. It cannot be prepared through a neutralisation reaction.
20%
C. The compound has both ionic and covalent bonds.
29%
D. There is a dative bond in the compound.
S1T3:
Which of the following ions does NOT attain a stable noble gas configuration or a pseudo-noble gas configuration?
Which of the following ions does NOT attain a stable noble gas configuration or a pseudo-noble gas configuration?
Final Results
15%
A. Li⁺
20%
B. O²⁻
41%
C. Cu⁺
25%
D. Mn²⁺
S1T3:
Which statement describes a covalent bond most precisely?
Which statement describes a covalent bond most precisely?
Final Results
10%
A. The sigma bond between non-metal atoms in a neutral molecule.
56%
B. The bonding between non-metal atoms through the sharing of electrons.
8%
C. The electrostatic forces of attraction between oppositely charged ions.
26%
D. The attractive forces between the nuclei of bonded atoms and the shared pair of electrons.
S1T3:
Which of the following statements is true about carbon dioxide molecule?
Which of the following statements is true about carbon dioxide molecule?
Final Results
4%
A. It has a tetrahedral shape.
61%
B. It is a non-polar molecule.
25%
C. It is an acidic diatomic covalent molecule.
10%
D. It contains one sigma bond and one pi bond.
S3T14:
How many structural isomers does a molecule with the formula C₄H₈ have?
How many structural isomers does a molecule with the formula C₄H₈ have?
Final Results
29%
A. 2
42%
B. 3
18%
C. 5
10%
D. 6
S1T3:
Which of the following are NOT covalent compounds?
1. O₃ 2. CO₂ 3. AlCl₃ 4. C₆H₅NH₃Cl
Which of the following are NOT covalent compounds?
1. O₃ 2. CO₂ 3. AlCl₃ 4. C₆H₅NH₃Cl
Final Results
26%
A. 1 and 3
45%
B. 1 and 4
6%
C. 1, 2 and 4
23%
D. 1, 3 and 4
S1T3:
Which of the following is an ionic compound?
Which of the following is an ionic compound?
Final Results
18%
A. BeCl₂
43%
B. AlF₃
19%
C. AlCl₃
19%
D. BF₃
S3T14:
Which of the following is a saturated hydrocarbon that contains an equivalent hydrogen atom at each carbon?
Which of the following is a saturated hydrocarbon that contains an equivalent hydrogen atom at each carbon?
Final Results
30%
A. Cyclopropane
42%
B. Benzene
23%
C. Butane
5%
D. Ethene
S3T14:
Which of the following statements is true about an organic compound with molar mass of 28.0 g mol⁻¹?
Which of the following statements is true about an organic compound with molar mass of 28.0 g mol⁻¹?
Final Results
11%
A. It contains a dative covalent bond in the molecule.
17%
B. The molecule contains three sigma bonds and one pi bond.
15%
C. It is a simple diatomic molecule with a triple covalent bond.
57%
D. It contains a double covalent bond between two identical atoms.
S1T3:
Which of the following statements is true about an inorganic compound with molar mass of 28.0 g mol⁻¹?
Which of the following statements is true about an inorganic compound with molar mass of 28.0 g mol⁻¹?
Final Results
18%
A. It is a reducing agent.
9%
B. The molecule has a trigonal planar shape.
31%
C. It is confirmed to be a nitrogen molecule.
42%
D. It can be either a polar or a nonpolar molecule.