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Public chemistry tools

Deterministic calculators for board practice

Molar mass, molarity, dilution, Raoult law, boiling point, freezing point, kinetics, Kohlrausch, Faraday, d-block, coordination, Nernst, pH, and ideal gas calculations run locally in the browser. Use them to check method, then move into answer-masked practice.

Molar Mass Calculator

Enter a formula to calculate molar mass and percent composition from local atomic masses.

Derivation is not hidden: identify the displayed equation, leave exactly one variable blank, then solve that equation algebraically before using the numeric result.

Coupled Physical Chemistry Visualizers - Chapters 1, 2 & Equilibrium Bridge

Interactive Henderson-Hasselbalch Buffer Curve & Gibbs-Nernst-Equilibrium Triangle Workbench

Inspect how conjugate base to weak acid ratios govern buffer capacity inside the pKa +/- 1.0 window, and trace the thermodynamic triangle linking standard cell potential (E^0_cell), standard Gibbs energy (Delta G^0), and equilibrium constant (K_c) at 298.15 K.

Panel A - Ionic Equilibrium & Bio-Buffer Bridge

Henderson-Hasselbalch Buffer Capacity & Titration Curve

pH = pKa + log10([Conjugate Base] / [Weak Acid]). Maximum acid/base shock resistance occurs within |pH - pKa| <= 1.0 (0.1 <= [Salt]/[Acid] <= 10).

0.10 M
0.01 M0.50 M1.00 M
0.10 M
0.01 M0.50 M1.00 M

[Salt] / [Acid]

1.000

log10(ratio)

+0.0000

Buffer pH

4.7600

pOH (298 K)

9.2400

Inside maximum buffer capacity window (|pH - pKa| = 0.00 <= 1.00; effective range 3.76 to 5.76).
Effective Buffer Capacity Band: pKa +/- 1.0 (3.76 to 5.76)pKa 4.765.763.76-1.5-1.0-0.50.0+0.5+1.0+1.5log10([A-] / [HA]) from -1.5 to +1.5pH = 4.76 (log = 0.00)

Algebraic Substitution & Board Context

pH = pKa + log10([Salt] / [Acid]) = 4.76 + log10(0.10 / 0.10) = 4.76 + (0.0000) = 4.7600

Canonical acidic buffer: equimolar [CH3COO-] = [CH3COOH] gives pH = pKa = 4.76 with maximum buffer capacity against strong acid or base spikes.

Panel B - CBSE Class XII Chapter 2 Electrochemistry Triangle

Gibbs-Nernst-Equilibrium Triangle Solver (E^0_cell, Delta G^0, K_c)

Connects Delta G^0 = -n * F * E^0_cell, log10(K_c) = (n * F * E^0_cell) / (2.302585093 * R * T), and Delta G^0 = -2.302585093 * R * T * log10(K_c) at T = 298.15 K.

+1.100 V
-2.00 V0.00 V+3.00 V
n = 2 mol e-
n = 1n = 3n = 6

Delta G^0 (kJ/mol)

-212.27 kJ/mol

log10(K_c) at 298.15 K

37.1877

Equilibrium Constant K_c

1.54 x 10^37

Spontaneous galvanic cell reaction (Delta G^0 < 0, E^0_cell > 0, K_c > 1)

Step-by-Step Thermodynamic Triangle Substitution (Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s))

1. Delta G^0 = -n * F * E^0_cell = -2 * 96485.33212 C/mol * 1.100 V = -212267.7 J/mol

2. Board Trap (J -> kJ division by 1000): Delta G^0 = -212267.7 / 1000 = -212.2677 kJ/mol

3. log10(K_c) = (n * F * E^0_cell) / (2.302585093 * R * T) = (2 * 96485.33212 * 1.100) / (2.302585093 * 8.314462618 * 298.15) = 37.1877

4. Cross-check Delta G^0 = -2.302585093 * R * T * log10(K_c) / 1000 = -212.2677 kJ/mol (K_c = 1.54 x 10^37)

NCERT Chapter 2 canonical galvanic cell: n = 2 mol e-, Delta G^0 = -212.27 kJ/mol, log10(K_c) = 37.1877.

Constants: F = 96485.33212 C/mol, R = 8.314462618 J/(mol*K), T = 298.15 K.

Compile Chapter 2 Electrochemistry paper