/// Modul Reaksi
/// Reaction Module
/// Menghitung massa hasil reaksi (m) dari jumlah mol (n) dan massa molar (Mr).
/// Calculates product mass (m) from the number of moles (n) and molar mass (Mr).
/// Rumus: m = n × Mr
/// Formula: m = n × Mr
/// Menghitung persentase hasil reaksi (%yield) dari massa aktual dan massa teoritis.
/// Calculates percent yield (%yield) from actual product mass and theoretical product mass.
/// Rumus: %yield = (massa aktual / massa teoritis) × 100
/// Formula: %yield = (actual mass / theoretical mass) × 100