Preparation of 70% Ethanol from 95% Ethanol

70% Ethanol is used as a disinfectant in labs. It is also used for washing DNA pellet to remove excess salt. It can be prepared by diluting 95% ethanol. For the preparation of 70% ethanol for analytical work, use analytical grade ethanol.

To prepare 1L of 70% Ethanol, take 736.84 ml of 95% ethanol and make up the final volume to 1L with water.


Reagents and solutions
95% Ethanol
Deionized water

Equipment and disposables
Measuring cylinder

70% aqueous solution of ethanol

Preparation of 1L of 70% ethanol in water


Use personal protective equipment (lab coat, gloves, goggles, etc) for your safety and follow your institute’s guidelines.

Step 1: Take 736.84 ml of 95% ethanol in a measuring cylinder.

Step 2: Adjust the final volume to 1000 ml with water. Mix it.

Note: You need to add 263.16 ml water. 

Solution can be stored at room temperature.

Follow the table to prepare 70% Ethanol of different volumes.
Ingredients / Volume500 ml1000 ml2500 ml10000 ml
95% Ethanol368.42 ml736.84 ml1842.11 ml7368.42 ml


131.58 ml

263.16 ml

657.89 ml

2631.58 ml

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