苏打

苏打 is a phonetic loan from English 'soda,' usually referring to sodium bicarbonate (baking soda) or soda water — not sugary soft drinks. Note the second syllable is 打 (rising tone), the loanword reading — NOT the verb 打 (to hit). The dá reading carries through to all derived compounds: 苏打水, 小苏打, 苏打粉.