AP Intermediate Chemistry (BIEAP) case studies
AP Intermediate Chemistry (BIEAP) · Put your knowledge to work in context.
The AP Intermediate Chemistry examination is the chemistry component of the two-year higher secondary programme administered by the Board of Intermediate Education, Andhra Pradesh (BIEAP). It is taken by students completing Intermediate first and second year, and its marks feed directly into higher-education admissions and eligibility for competitive entrance tests in engineering, medicine, agriculture and pure sciences. The AP Intermediate Chemistry (BIEAP) case studies are 5 cases and about 3,889 words.
1Assigning the Lines in a Hydrogen Spectrum Report
In a practical class, students record the emission spectrum of a low-pressure hydrogen discharge tube using a grating spectrograph whose manual quotes a usable range of 200–800 nm and a resolution of 0.5 nm. One student logs four lines at 656.3, 486.1, 434.0 and 410.2 nm.
781 words, about 4 min2Preparing an Acetate Buffer Without Sodium Acetate
A biochemistry practical needs 250.0 mL of acetate buffer at pH 5.00 with a total acetate concentration ([CH3COOH] + [CH3COO⁻]) of 0.100 M, because higher ionic strength inhibits the enzyme being studied. The shelf holds glacial acetic acid (17.4 M; density 1.05 g mL⁻¹), NaOH pellets (M = 40.00 g mol⁻¹) and distilled water, but the sodium acetate bottle is empty.
826 words, about 4 min3When the Voltmeter Disagrees with the Table
A student assembles a cell at 298 K: a zinc electrode in 0.010 M ZnSO4 joined by a KNO3 salt bridge to a copper electrode in 0.50 M CuSO4. A high-impedance digital voltmeter reads 1.15 V.
731 words, about 4 min4The Iodine Clock that Refused to Obey Its Own Rate Law
A student studies the persulphate–iodide reaction at 25 °C using the iodine clock: S2O8²⁻(aq) + 2I⁻(aq) → 2SO4²⁻(aq) + I2(aq) Every 50.0 mL run contains 1.00 mL of 0.0100 M Na2S2O3 and a few drops of starch, and the time to the first blue colour is recorded. Results: run 1, [S2O8²⁻] = 0.0200 M, [I⁻] = 0.0200 M, t = 45 s; run 2, [S2O8²⁻] = 0.0400 M, [I⁻] = 0.0200 M, t = 46 s; run 3, [S2O8²⁻] = 0.0200 M, [I⁻] = 0.0400 M, t = 23 s.
804 words, about 4 min5Two Routes to a Bromide: Rearrangement versus Inversion
A second-year student must convert (R)-3-methylbutan-2-ol into a bromoalkane. Route A is concentrated HBr at room temperature; route B is PBr3 in dry ether at 0 °C.
747 words, about 4 min