Digital ACT Practice Questions

A botany student analyzed spinach leaf pigments using paper chromatography with petroleum ether solvent: - Solvent front distance: 10.0 cm - Carotene: 9.5 cm (R...

Potato tuber cores (initial mass 5.00 g) were immersed in sucrose solutions for 2 hours: - 0.0 M sucrose: Final mass = 5.82 g (+16.4%) - 0.2 M sucrose: Final ma...

The effusion times for 100 mL of four gases through a pinhole at 298 K were recorded: - Gas 1 (He, 4 g/mol): 10.0 s - Gas 2 (CH4, 16 g/mol): 20.0 s - Gas 3 (N2,...

A stationary microphone recorded sound frequencies from a 500 Hz siren moving at various velocities toward the microphone: - 0 m/s: 500 Hz - 10 m/s: 515 Hz - 20...

Identical 1.000-meter metal rods were heated from 20°C to 120°C (delta T = 100°C): - Invar: Elongation = 0.12 mm - Steel: Elongation = 1.20 mm - Copper: Elongat...

A chemistry lab added calcium chloride (CaCl2) to 1.0 kg of water and measured freezing points: - 0.0 mol CaCl2: 0.00°C - 0.5 mol CaCl2: -2.79°C - 1.0 mol CaCl2...

Physicists irradiated a cesium metal plate with photons of various frequencies: - Frequency = 4.0 x 10^14 Hz: Kinetic energy of ejected electrons = 0.00 eV (no ...

A capacitor in an RC circuit discharges through a resistor. Voltage across capacitor was recorded: - 0 s: 12.0 V - 2 s: 7.3 V - 4 s: 4.4 V - 6 s: 2.7 V - 8 s: 1...

Students mixed 50 mL of 1.0 M HCl with 50 mL of 1.0 M NaOH in a coffee cup calorimeter: - Initial temperature: 21.0°C - Final temperature: 27.8°C - Calculated d...

Tracers measured groundwater contaminant plume speed in two aquifer formations: - Formation 1 (Coarse Gravel): Velocity = 14.5 m/day - Formation 2 (Fine Silt): ...

A physics acoustics team measured the speed of sound through four media at 20°C: - Air: 343 m/s - Helium: 965 m/s - Water: 1,482 m/s - Steel: 5,960 m/s Sound tr...

E. coli was cultured in nutrient broth at 37°C. Optical density at 600 nm was recorded: - 0 hr (Lag): OD = 0.05 - 2 hr (Log): OD = 0.22 - 4 hr (Log): OD = 0.88 ...

A 0.5 kg mass on a string rotates in a horizontal circle of radius 1.0 m at various linear velocities: - v = 2.0 m/s: Tension = 2.0 N - v = 4.0 m/s: Tension = 8...

A chemist compared 50 mL of unbuffered water to 50 mL of 0.1 M phosphate buffer (initial pH 7.00): - Adding 1.0 mL of 1.0 M HCl to water: pH drops to 1.70 - Add...

Oceanographers mapped alternating normal and reversed magnetic stripes across the Mid-Atlantic Ridge: - The magnetic anomaly pattern on the west side of the rid...

A 632.8 nm red helium-neon laser passed through a diffraction grating (500 lines/mm): - Screen distance D = 1.0 m: Fringe distance y = 32.5 cm - Screen distance...

Onion root tip cells were treated with colchicine (which arrests cells in metaphase): - Control: 8% of cells in metaphase - 0.01% Colchicine: 24% of cells in me...

The solubility of potassium chlorate (KClO3) in 100 g of water was measured: - 20°C: 7.3 g - 40°C: 14.0 g - 60°C: 24.5 g - 80°C: 38.5 g If a saturated solution ...

In a classic genetics cross between heterozygous purple-flowered pea plants (Pp x Pp): - Purple offspring: 705 - White offspring: 224 The observed phenotypic ra...

A solenoid with 500 turns had magnetic field B measured at its center: - Current = 1.0 A: B = 1.26 mT - Current = 2.0 A: B = 2.51 mT - Current = 3.0 A: B = 3.77...

Acetic acid and ethanol react to form ethyl acetate: CH3COOH + C2H5OH CH3COOC2H5 + H2O. - Trial 1 (No catalyst, 25°C): Equilibrium reached after 48 hours - Tria...

Paleoclimatologists analyzed oxygen-18 (delta 18O) in an Antarctic ice core: - Modern ice (0 m depth): delta 18O = -35.0 permil - Glacial maximum ice (2,000 m d...

A 100 cm^3 solid brass cylinder was submerged in various liquids and the buoyant force was measured: - Gasoline (density = 0.68 g/cm^3): Buoyant force = 0.67 N ...

Arabidopsis thaliana seeds were germinated on agar plates containing NaCl: - 0 mM NaCl: 98% germination - 50 mM NaCl: 92% germination - 100 mM NaCl: 64% germina...