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由于水的导电性很弱，为了增强水的导电性，做电解水实验时常在水中加入少量氢氧化钠固体(在水电解过程中，氢氧化钠质量和性质都不发生变化)。把 180 克氢氧化钠的质...

Mar 19, 2024

由于水的导电性很弱，为了增强水的导电性，做电解水实验时常在水中加入少量氢氧化钠固体(在水电解过程中，氢氧化钠质量和性质都不发生变化)。把 180 克氢氧化钠的质量分数为1%的溶液进行电解，电解结束后氨氧化钠的质量分数为1.2%. 在水电解过程中，有多少克水被电解了?

Solution

Calculate the mass of NaOH in the solution: Given a 1% NaOH solution, we can find the mass of NaOH by calculating 1% of the total mass of the solution

Calculate the mass of water in the solution: Subtract the mass of NaOH from the total mass of the solution to find the mass of water before electrolysis

Calculate the new mass of NaOH: After electrolysis, the mass fraction of NaOH is 1.2%. We can use this to find the new mass of NaOH in the solution

Calculate the mass of water after electrolysis: Since the mass of NaOH does not change during electrolysis, we can find the new total mass of the solution and then calculate the mass of water after electrolysis

Determine the mass of water electrolyzed: Subtract the mass of water after electrolysis from the mass of water before electrolysis to find the mass of water that has been electrolyzed

Answer

2 grams of water have been electrolyzed.

Key Concept

Mass conservation of NaOH during electrolysis

Explanation

Since the mass and properties of NaOH do not change during the electrolysis, we can use the change in mass fraction to determine the mass of water electrolyzed.