GAMSAT formula sheet: 53 chemistry and physics formulas to print

Chemistry: 21 formulas

Amounts and solutions

Moles from mass $n = \dfrac{m}{M}$ n moles, m mass in grams, M molar mass in g/mol.
Concentration $c = \dfrac{n}{V}$ c in mol/L, V volume of solution in litres.
Dilution $c_1 V_1 = c_2 V_2$ The moles of solute stay the same when water is added.
Ideal gas law $pV = nRT$ T in kelvin. R is the gas constant.
Combined gas law $\dfrac{p_1 V_1}{T_1} = \dfrac{p_2 V_2}{T_2}$ A fixed amount of gas. T in kelvin.
Percentage yield $\text{yield} = \dfrac{\text{actual}}{\text{theoretical}} \times 100\%$ Both amounts in the same unit.

Acids and bases

pH $\mathrm{pH} = -\log_{10}[\mathrm{H^+}]$ A tenfold rise in hydrogen ion concentration lowers pH by 1.
Ionic product of water $K_w = [\mathrm{H^+}][\mathrm{OH^-}] = 1.0 \times 10^{-14}$ At 25 °C, so pH + pOH = 14.
Acid dissociation constant $K_a = \dfrac{[\mathrm{H^+}][\mathrm{A^-}]}{[\mathrm{HA}]}$ For a weak acid HA. A larger value means a stronger acid.
pKa $\mathrm{p}K_a = -\log_{10} K_a$ A smaller value means a stronger acid.
Buffer pH (Henderson–Hasselbalch) $\mathrm{pH} = \mathrm{p}K_a + \log_{10}\dfrac{[\mathrm{A^-}]}{[\mathrm{HA}]}$ When the two concentrations are equal, pH equals pKa.

Equilibrium and rates

Equilibrium constant $K_c = \dfrac{[\mathrm{C}]^c[\mathrm{D}]^d}{[\mathrm{A}]^a[\mathrm{B}]^b}$ For aA + bB ⇌ cC + dD. Products over reactants.
Rate law $\text{rate} = k[\mathrm{A}]^m[\mathrm{B}]^n$ The orders m and n come from experiment, not from the equation.
First-order half-life $t_{1/2} = \dfrac{\ln 2}{k}$ The same at every concentration. ln 2 is about 0.693.
Arrhenius equation $k = A e^{-E_a/RT}$ A higher temperature or a lower activation energy gives a larger rate constant.

Energy and electrochemistry

Heat transferred $q = mc\Delta T$ c is the specific heat capacity.
Enthalpy change from bond energies $\Delta H = \sum E_{\text{bonds broken}} - \sum E_{\text{bonds formed}}$ Breaking bonds takes energy in; forming bonds gives it out.
Gibbs free energy $\Delta G = \Delta H - T\Delta S$ A reaction is spontaneous when ΔG is negative. T in kelvin.
Free energy and equilibrium $\Delta G^\circ = -RT \ln K$ K greater than 1 gives a negative standard free energy change.
Standard cell potential $E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}}$ Both as standard reduction potentials. Reduction happens at the cathode.
Free energy and cell potential $\Delta G^\circ = -nFE^\circ$ n moles of electrons transferred, F the Faraday constant.

Physics: 32 formulas

Motion

Velocity under constant acceleration $v = u + at$ u initial velocity, v final velocity.
Displacement under constant acceleration $s = ut + \tfrac{1}{2}at^2$ Constant acceleration only.
Velocity and displacement $v^2 = u^2 + 2as$ Use it when time is not given.
Displacement from average velocity $s = \tfrac{1}{2}(u + v)t$ Constant acceleration only.
Centripetal acceleration $a = \dfrac{v^2}{r}$ Towards the centre of the circle.

Forces and energy

Newton's second law $F = ma$ F is the resultant force.
Weight $W = mg$ g is about 9.8 m/s² at the Earth's surface.
Momentum $p = mv$ Total momentum is conserved when no outside force acts.
Impulse $F\Delta t = \Delta p$ A longer contact time means a smaller force for the same change in momentum.
Work done $W = Fs\cos\theta$ θ is the angle between the force and the displacement.
Kinetic energy $E_k = \tfrac{1}{2}mv^2$ Doubling the speed gives four times the kinetic energy.
Gravitational potential energy $E_p = mgh$ Near the Earth's surface.
Power $P = \dfrac{W}{t} = Fv$ Work done per second.
Hooke's law $F = kx$ x is the extension. The energy stored is ½kx².
Moment of a force $\tau = Fd$ d is the perpendicular distance from the pivot to the line of the force.

Fluids

Density $\rho = \dfrac{m}{V}$ Water is 1,000 kg/m³, or 1 g/mL.
Pressure $P = \dfrac{F}{A}$ Force per unit area.
Pressure in a fluid $P = \rho g h$ h is the depth below the surface.
Continuity $A_1 v_1 = A_2 v_2$ A fluid speeds up where the tube narrows.

Electricity

Charge $Q = It$ Current is charge per second.
Ohm's law $V = IR$ For a resistor at constant temperature.
Electrical power $P = VI = I^2R = \dfrac{V^2}{R}$ Three forms of the same relationship.
Resistors in series $R = R_1 + R_2$ The same current flows through each.
Resistors in parallel $\dfrac{1}{R} = \dfrac{1}{R_1} + \dfrac{1}{R_2}$ The total is less than the smallest resistor.
Capacitance $C = \dfrac{Q}{V}$ Charge stored per volt.

Waves, light and decay

Wave speed $v = f\lambda$ Frequency times wavelength.
Period $T = \dfrac{1}{f}$ The time for one complete wave.
Snell's law $n_1 \sin\theta_1 = n_2 \sin\theta_2$ Angles are measured from the normal.
Refractive index $n = \dfrac{c}{v}$ c is the speed of light in a vacuum, v its speed in the material.
Thin lens equation $\dfrac{1}{f} = \dfrac{1}{d_o} + \dfrac{1}{d_i}$ f is the focal length; the others are the object and image distances. Magnification has size d_i over d_o.
Photon energy $E = hf$ h is the Planck constant.
Radioactive decay $N = N_0 \left(\tfrac{1}{2}\right)^{t/t_{1/2}}$ The amount halves every half-life.

Recall quiz: 27 formulas

Each question names a formula and shows three versions. Pick the right one. The ones you miss come back at the end.

Chemistry · Amounts and solutions1 of 27

Moles from mass: which is right?

Now use them

A formula earns marks only when you can apply it to data you have not seen. Section 3 gives you two minutes a question and no calculator.

Questions people ask

Do you get a formula sheet in GAMSAT?

ACER publishes no formula sheet for GAMSAT, and its list of what to bring does not include one. This sheet is our own, for revision.

Can you use a calculator in GAMSAT?

No. Calculators are on ACER's list of prohibited items, so every calculation is done by hand.

What science do I need for GAMSAT Section 3?

ACER says first-year university chemistry and biology and Year 12 physics. The section is 40% chemistry, 40% biology and 20% physics.

Is memorising formulas enough for Section 3?

No. ACER says the section tests problem solving and the use of knowledge, as well as recall of basic science. Learn the formulas so they cost no time, then practise applying them to unfamiliar data.

Why is there no biology on this sheet?

GAMSAT biology questions turn on reading experiments, pathways and data, not on formulas. This sheet covers the two subjects where a formula is the starting point.

How do I print the formula sheet?

Press Print the sheet. Only the formula list prints: chemistry on one page, physics on the next two. Choose Save as PDF in the print window to keep a copy.