How to mix 95 alcohol with 75 alcohol

How do you make 75% alcohol from 95% alcohol? This may have been taught by the teacher in the classroom, but when it comes to practical application, it will always be confusing and overwhelmed. In order to facilitate the students of Guangzhou University and friends in need in work and life, today Qianxiazi will talk to you about how to match each other between 75% and 95%!

Universal formula: 95%*a=75%*b

Pure water required c=b-a

A and B are the total volume of 95% and 75% alcohol respectively, which is the key to the interformulation between the two.

At the same time, it is necessary to pay attention to the total volume, 95% and 75% of the alcohol volume and pure water volume c respectively after calculation, so as not to be confused.

Now use an example to illustrate the principle and application of formula derivation.

Example 1: How much ml 95% alcohol is required to make 100ml of 75% alcohol?

Solution 1: Substituting the universal formula, because b = 100ml, so 95% * a = 75% * 100, then a = 75% * 100 95% = total volume of alcohol), the required pure water is. That is, alcohol plus pure water is 75% alcohol.

Solution 2 (Decomposition Step):

1. Because c = n v, so 75 100 = 75%, that is, 75ml of alcohol is needed in the total volume of 100ml to constitute 75% alcohol, and the amount of the substance in the preparation is unchanged, that is, the amount of the substance of 75mol alcohol;

How many ml of alcohol 'substance' do I need to change to 95% alcohol? Because n=v*c, v=nc, so 75 95%=, that is, the amount of the same substance is 75mol, and the alcohol to be added to the purified water to the total volume is 100ml.

3. At this time, 1 and 2 have the same points, so 1 and 2 can be integrated as: 75 100 = 95% * v 100, and v = 75% * 100 95%.

Integrating this, solution 2 regresses to solution 1, which is our universal formula.

Example 2: How many ml of 100ml of 95% alcohol can be made into 75% alcohol?

Solution: 95%*a=75%*b, already know a=100ml, find.

This is the total volume of 75% alcohol, including water and 95% alcohol, so pure water is required for preparation, plus the original 100ml of 95% alcohol.

Hehehehe, seeing that today's experience sharing here has ended, let's sort out our thoughts again! Think positively, draw inferences, and operate carefully, and you will definitely be able to do a good job! Come on!

First of all, find the mass in 95% of the alcohol, which is to use the mass of this bottle of alcohol, multiply it by 95%, which is the mass of the alcohol in this bottle of alcohol solution. In order to prepare a concentration of 75 percent alcohol, it is necessary to calculate the mass of water that needs to be added to 95 percent of the alcohol, first use the mass of the alcohol that is called for above, divide it by 75 percent, and then find the mass of 75 percent of the alcohol, and subtract the mass of the previous 95 percent of the alcohol to find the mass of the water added. This makes 95 percent alcohol to make 75 percent alcohol.

With the addition of water, the mass ratio of the alcohol solution to water is 15 to 4

A 75% alcohol is made by adding a certain percentage of distilled water to 95% alcohol.

For example, if 100ml of 95% alcohol is added, distilled water needs to be added to prepare 75% alcohol.

95% alcohol means that the volume of alcohol accounts for 95% of the total volume of the solution. For example, 100ml of 95% alcohol is alcohol, 95ml of distilled water is added, alcohol:solution = 95:100.

Suppose adding aml of distilled water to 100 ml of 95% alcohol makes it 75% alcohol, then the total volume of the solution at this point is (100+a) ml.

Then the configuration of 75% alcohol needs to meet: 95 (a+100)=75 100 to find: a =