Answer:
Alchemy is based on mystic view of reality whereas chemistry is based on experiments, observations and facts.
<u>Answer:</u> Mixture can be separated into its components but impure substance cannot be separated into components.
<u>Explanation:</u>
A mixture is defined as a combination of two or more different substances in which the component substances are individually distinct. The substances can be separated by physical processes. The separation dos not involve any chemical process because no new substance is being formed.
Impure substance is defined as a substance which can be mixture of elements, compounds or elements and compounds. The substances cannot be separated by physical means but can only be separated by chemical means.
Chemical change can be determined when a substance change it's state of composition and is irreversible. Five evidences that chemical change has occured are, color change, formation of a precipitate, formation of gas, odor change, temperature change. Examples of chemical change are, combustion reactions, rusting iron, precipitate of AgCl.
Answer:
29.9 moles
2C²H¹⁰ needs 13 moles of O²
4.6 C⁴H¹⁰ needs X moles of O²
X= 13× 4.6 ÷ 2 = 59.8 ÷ 2 = 29.9 moles
Answer:Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds. Elements cannot be divided into smaller units without large amounts of energy.