Solid State And Instrumental Analysis Mock Tests

In the mass spectrum of 2-pentanone (CH₃COCH₂CH₂CH₃), the McLafferty rearrangement produces a characteristic fragment ion. What is the m/z value of the McLafferty rearrangement peak, and what neutral molecule is lost? (The McLafferty rearrangement requires a carbonyl compound with a gamma hydrogen atom relative to the carbonyl group. It involves a six-membered cyclic transition state with transfer of the gamma hydrogen to the carbonyl oxygen, followed by cleavage of the alpha-beta bond.)

The FTIR spectrum of acetone (CH₃COCH₃) shows a strong absorption at approximately 1715 cm⁻¹. This band corresponds to:

X-ray diffraction from a crystal with interplanar spacing d = 2.82 Å gives a first-order reflection at a glancing angle of 30°. What is the wavelength of the X-rays used? (Use Bragg's law)

Titanium dioxide (TiO₂) crystallizes in the rutile structure, which can be described as a body-centred tetragonal lattice. In this structure, each Ti⁴⁺ ion is surrounded by 6 O²⁻ ions, and each O²⁻ ion is bonded to 3 Ti⁴⁺ ions. What are the coordination numbers of Ti and O in the rutile structure, and how many formula units of TiO₂ are present per unit cell? (The unit cell contains Ti atoms at the corners and body centre, and O atoms at specific positions within the cell.)

The Bragg angle θ for the first-order reflection (n = 1) from the (111) planes of a cubic crystal with lattice parameter a = 4.08 Å, using X-rays of wavelength λ = 1.54 Å, is closest to:

In high-performance liquid chromatography (HPLC) using a reversed-phase column (C₁₈ stationary phase and polar mobile phase such as methanol/water), which of the following compounds would have the longest retention time? (Consider the hydrophobic interactions between the non-polar C₁₈ stationary phase and the analytes.)

Sodium chloride (NaCl) crystallises in a face-centred cubic lattice. What is the coordination number of Na⁺ and Cl⁻ ions, respectively, and how many formula units of NaCl are present per unit cell?

The Cramer's rule is applied to solve simultaneous linear equations in various areas of chemistry. In the context of solving for the composition of a binary mixture using absorbance measurements at two wavelengths, the system of equations is: A₁ = ε₁ₐcₐl + ε₁ᵦcᵦl and A₂ = ε₂ₐcₐl + ε₂ᵦcᵦl. Using Cramer's rule, the concentration cₐ is given by (where Δ = ε₁ₐε₂ᵦ - ε₁ᵦε₂ₐ):