All the chemical experiments without proper protective measures are very dangerous and should be avoided as far as possible. The waste gas, waste water and waste residue produced in the reaction shall be well treated and shall not be discharged at will. Warning: the experiment described below involves sodium hydroxide, a highly corrosive drug. Please take protective measures. Do not use the reactants or products for illegal crimes. Any consequences caused by failure to follow the warning shall be borne by the person who fails to follow.

1.材料准备一袋纯碱（碳酸钠）

1. Material preparation: a bag of soda ash (sodium carbonate)

【4～5RMB  一包250g左右】小包波力/喜之郎海苔

[4-5rmb, about 250G / pack] xiaobaoboli / Xizhilang seaweed

【1.2RMB/包 两包】小瓶矿泉水（怡宝或农夫山泉）

[1.2 RMB / two bags] small bottle of mineral water (Yibao or nongfushan spring)

【1.2RMB/瓶 需要两瓶】两到三张餐巾纸两到三张作业本上的纸2.反应原理：CaO + H2O ==== Ca(OH)2

[1.2 RMB / bottle needs two bottles] two to three napkins, two to three sheets of paper on the operating book 2. Reaction principle: Cao + H2O = = = Ca (OH) 2

Ca(OH)2 + Na2CO3 ====2NaOH + CaCO3（沉淀）

Ca (OH) 2 + Na2CO3 = = = 2naoh + CaCO3 (precipitate)

1.将海苔吃掉，干燥剂取出备用。将一瓶矿泉水（下文中为A）喝掉三分之一。

1. Eat the seaweed and take out the desiccant for standby. Drink one third of a bottle of mineral water (a below).

2.将干燥剂倒入A中，静待反应结束（小心烫伤）。【等待时将另一瓶矿泉水B喝光】

2. Pour the desiccant into a and wait until the reaction is over (be careful of scalding). [drink up another bottle of mineral water b while waiting]

3.向A中加入纯碱，直无沉淀生成。

3. Add soda ash into a until there is no precipitation.

4.静置，使沉淀沉降。

4. Allow it to settle.

5.将餐巾纸和作业纸像滤纸一样叠好，放在B瓶口。

5. Fold the napkin and working paper like filter paper and put them at the mouth of bottle B.

6.过滤注：

6. Filter note:

1.此方法制得的氢氧化钠溶液较稀，可短时间小剂量直接接触。

1. The sodium hydroxide solution prepared by this method is relatively thin and can be directly contacted in a short time and small dose.

2.溶液会在两到四天内将塑料瓶蚀穿，请注意更换容器，以免造成损失。

2. The solution will corrode the plastic bottle within two to four days. Please replace the container to avoid loss.