Bagrut Chemistry case studies
Bagrut Chemistry · Put your knowledge to work in context.
The Bagrut in Chemistry is the Israeli matriculation (Bagrut) examination in chemistry, taken by high-school students who choose chemistry as an elective subject and by external candidates completing matriculation requirements. It is a written, Hebrew-language examination built around the standard Israeli chemistry curriculum: atomic structure and the periodic table, bonding and intermolecular forces, the mole and stoichiometry, states of matter, equilibrium, acids and bases including buffers, thermochemistry, electrochemistry, kinetics, and organic chemistry. The Bagrut Chemistry case studies are 5 cases and about 4,553 words.
1Argon, Catalysts and Colour: Judging Shifts in the N2O4/NO2 Equilibrium
A 2.00 L sealed glass flask held at 298 K contains 0.0800 mol of colourless N2O4(g). The flask has a piston that can be locked in place or left free to move, and a septum through which gases can be injected.
863 words, about 4 min2Preparing and Stress-Testing an Acetate Buffer of pH 5.00
A technician must prepare 1.00 L of an acetate buffer for a teaching laboratory. She measures 0.100 mol of pure acetic acid (Ka = 1.8×10⁻⁵, pKa = 4.74) into a 1.00 L volumetric flask, adds 0.0500 mol of solid NaOH, swirls until it dissolves, and makes up to the mark with distilled water.
897 words, about 4 min3Nickel Plating versus Galvanising for Steel Brackets in a Marine Yard
Steel brackets for a seaside installation must be protected against corrosion. The workshop can either nickel-plate the brackets or hot-dip galvanise them.
980 words, about 5 min4Identifying Three C4H9Br Isomers from Kinetic Data and Product Distributions
Three unlabelled bottles A, B and C each contain one isomer of C4H9Br. A student measures initial rates of reaction with hydroxide in aqueous ethanol at 25 °C, keeping the haloalkane concentration fixed at 0.100 mol L⁻¹: Bottle A: with 0.100 mol L⁻¹ OH⁻, rate = 2.0×10⁻⁴ mol L⁻¹ s⁻¹; with 0.200 mol L⁻¹ OH⁻, rate = 4.0×10⁻⁴ mol L⁻¹ s⁻¹.
883 words, about 4 min5Hydrogen Collected over Water: Limiting Reagent and Vapour-Pressure Corrections
A student is asked to prepare hydrogen and measure the yield. She weighs out 0.0500 mol of zinc granules, adds 25.0 mL of 2.00 mol L⁻¹ HCl, and collects the gas over water in an inverted, graduated burette at 22.0 °C.
930 words, about 5 min