Interatomic Bonding
What type of bond is formed between two identical non-metal atoms?
Nonpolar covalent bond
What type of intermolecular force is strongest: London dispersion, dipole-dipole, or hydrogen bonding?
Hydrogen bonding
What is the hybridization of carbon in methane (CH₄)?
sp³
At STP, what is the volume of 1 mole of any ideal gas?
22.4 L
How many atoms are in 1 mole of carbon?
6.022×1023 atoms
Which element is most likely to form covalent bonds with hydrogen: sodium, chlorine, or oxygen?
Oxygen
Which molecule has stronger intermolecular forces: H₂O or CO₂?
H₂O (because of hydrogen bonding).
What is the bond angle in an sp² hybridized atom?
120°
A sample of oxygen gas occupies 2.5 L at 1 atm. What will its volume be at 2 atm (constant T)?
1.25 L (Boyle’s law: V₂ = V₁P₁/P₂).
Calculate the molar mass of CaCO₃.
100 g/mol (Ca=40, C=12, O=16×3=48)
Why does carbon form four covalent bonds instead of two?
Carbon has 4 valence electrons and needs 4 more to complete its octet.
Why does NH₃ have a higher boiling point than PH₃?
NH₃ forms hydrogen bonds, while PH₃ only has weak van der Waals forces.
Determine the hybridization of the central atom in BeCl₂
sp
A gas has a pressure of 0.5 atm at 300 K. What is its pressure at 600 K (constant V)?
1.0 atm (Gay-Lussac’s law: P₂ = P₁T₂/T₁).
Calculate the number of molecules in 10 g of CH₄.
10/16 = 0.625 mol → 0.625 × 6.022×10²³ = 3.76×10²³ molecules.
Which is more ionic: NaCl or MgCl₂?
MgCl₂ (Mg²⁺ has higher charge → stronger ionic character).
Arrange the following in order of increasing strength of intermolecular forces: CH₄, H₂O, HCl.
CH₄ < HCl < H₂O
In ethyne (C₂H₂), how many sigma and pi bonds are present?
3 sigma bonds and 2 pi bonds
A balloon contains 4.0 L of gas at 27°C (300 K). What volume will it occupy at 77°C (350 K), pressure constant?
4.67 L (Charles’ law: V₂ = V₁T₂/T₁).
How many liters of H₂ at STP are produced from 4 g of H₂O according to:
2H2O→2H2+O2?
4 g H₂O = 0.222 mol → 0.222 mol H₂ = 4.97 L.
Predict the bond type in BF₃ and explain why it is polar or nonpolar.
Covalent; BF₃ is nonpolar overall because the molecule is symmetrical, even though B–F bonds are polar
Explain why ice is less dense than liquid water.
In ice, hydrogen bonds hold water molecules in an open lattice structure, increasing volume and lowering density.
Predict the hybridization of sulfur in SF₆ and explain.
sp³d², because sulfur forms 6 sigma bonds with fluorine atoms in an octahedral geometry.
Calculate the pressure exerted by 0.5 mol of an ideal gas in a 10 L container at 300 K (R = 0.0821 L·atm/mol·K).
P = nRT/V = (0.5×0.0821×300)/10 = 1.23 atm
What mass of CaCO₃ is required to produce 11.2 L of CO₂ at STP?
CaCO3→CaO+CO2
11.2 L = 0.5 mol CO₂ → needs 0.5 mol CaCO₃ → 0.5×100 = 50 g.