Chemistry Quiz

Which of the following is NOT a step in gravimetric analysis?

• Precipitation

• Titration

• Filtration

• Drying

Bohr’s model of the atom was successful in explaining:

• The spectra of multi-electron atoms

• The shape of electron orbitals

• The quantization of electron energy levels in hydrogen

• The uncertainty principle

Which of the following elements has the highest electronegativity?

• Sodium

• Carbon

• Oxygen

• Fluorine

The wavelength of light emitted when an electron transitions from n=3 to n=2 falls in which region of the electromagnetic spectrum?

• Infrared

• 
  Ultraviolet

• visible

• X-ray

In the reaction: 2H₂ + O₂ → 2H₂O, which substance is the oxidizing agent?

• H₂

• O₂

• H₂O

• None

What is the standard enthalpy change of formation (ΔHf°) of an element in its most stable form?

• 0 kJ/mol

• 1 kJ/mol

• -100 kJ/mol

• Depends on the element

Compare the Bohr model and the quantum mechanical model of the atom. What key improvements does the quantum model offer?

Explain two possible sources of error in gravimetric analysis and how they affect the final result.

Does Bohr’s model correctly explain the spectra of all elements in the periodic table?

• Yes

• No

Can the dilution formula M1V1=M2V2M_1V_1 = M_2V_2M1​V1​=M2​V2​ be used to find the final concentration after mixing two different solutions?

• Yes

• No

Answer explanation

The dilution formula applies when diluting a solution with a solvent, not when mixing two solutions with different concentrations.