Answer:
2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.
Explanation:
Suppose x is the number of litres added to the 10% mixture than the quantity of new mixture is given as below
litres
litres
Also the quantity of alcohol is given as
Now the equation is as

So 2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.
Answer:
A chemical formula for a molecular compound represents the composition of <u><em>a molecule.</em></u>
Explanation:
Chemical formulas are alphanumeric expressions that are used to indicate the composition of chemical substances. They consist of chemical symbols that indicate the elements that form a compound; The number of atoms provided by each element is also indicated by the use of a subscript, that is, a small number that is placed below and to the right of each element that so requires. When an element does not have a subscript, it is understood that there is only one atom of it in the substance.
Each molecule corresponds to a chemical formula, as well as a name according to the rules of the chemical nomenclature.
Then, <u><em>a chemical formula for a molecular compound represents the composition of a molecule.</em></u>
Answer:
When you walk your dog, you are using energy from the sunlight to power the activity. Explain. The energy you use is transferred from glucose, which got it directly from sunlight.
Explanation:
Answer:
any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g., iron, manganese, chromium, and copper. Chemically they show variable valence and a strong tendency to form coordination compounds, and many of their compounds are colored.
Explanation: