Sodium Percarbonate (or sodium carbonate peroxyhydrate) is an addition compound of sodium carbonate and hydrogen peroxide. When dissolved into water, its releases H2O2and soda ash (sodium carbonate).
2Na2CO3 . 3H2O2 → 2Na2CO3 + 3H2O2
The pH of the resulting solution is typically alkaline, which activates the H2O2 for bleaching. The dry powder contains about 30% w/w H2O2.