过氧化钙晶体$\left(CaO_{2}\cdot xH_{2}O\right)$是优良的供氧剂，受热会逐渐失水，$120^{\circ}\mathrm{C}$时完全分解为$CaO_{2}$，$350^{\circ}\mathrm{C}$时$CaO_{2}$迅速分解为$CaO$和$O_{2}$.
（一$)1$、$CaO_{2}$和盐酸发生复分解反应生成氯化钙和过氧化氢，反应的化学方程式为：$CaO_{2}+2HCl$═$CaCl_{2}+H_{2}O_{2}$.故填：$CaO_{2}+2HCl...
