Ascientist has 40 liters of a 50% acidic solution. she adds a 20% acidic solution to create a mixture that has been diluted to
have 30% acidity. the graph models the percent of acidity in the final mixture.
20 40 60 80
how many liters of the 20% acidic solution should be added to create the needed 30% acidity in the final mixture?

a: 0.5
b: 30
c: 80
d: 37

C. 80 liters

Step-by-step explanation:

A scientist has 40 liters of a 50% acidic solution. So, there are

of acid in this solution.

She adds x liters of 20% acidic solution to create a new mixture. In x liters of 20% acidic solution there are

of acid.

The total volume of the mixture is (40 + x) liters. This mixture has 30% acidity, so there are

of acid.

The amount of acid is the same, thus,

C) 80 L

Step-by-step explanation:

According to the dilution law,

where,

= concentration of acid solution = 50 %

= volume of acid solution = 40 L

= concentration of another acid solution= 20%

= volume of another acid solution= x L

= concentration of resulting acid solution = 30 %

= volume of resulting acid solution = (40+x) L

Putting the values in the equation:

Thus 80 L of the 20% acidic solution should be added to create the needed 30% acidity in the final mixture.

step-by-step explanation: the declaration of the rights of man and of the citizen (french: déclaration des droits de l'homme et du citoyen de 1789), set by france's national constituent assembly in 1789, is a human civil rights document from the french revolution.[1]

the declaration was drafted by the abbé sieyès and the marquis de lafayette, in consultation with thomas jefferson.[2] influenced by the doctrine of "natural right", the rights of man are held to be universal: valid at all times and in every place, pertaining to human nature itself. it became the basis for a nation of free individuals protected equally by the law. it is included in the beginning of the constitutions of both the fourth french republic (1946) and fifth republic (1958) and is still current. inspired by the enlightenment philosophers, the declaration was a core statement of the values of the french revolution and had a major impact on the development of freedom and democracy in europe and worldwide.[3]

the 1789 declaration, together with the 1215 magna carta, the 1689 english bill of rights (1689), the 1776 united states declaration of independence, and the 1789 united states bill of rights, inspired in large part the 1948 united nations universal declaration of human rights