AC-HPAT – CHEMISTRY EXAM 2023/2024 WITH 100% CORRECT ANSWERS

double-displacement reaction - correct answer is a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds. Precipitate - correct answer is an insoluble solid that emerges from a liquid solution. The emergence of the insoluble solid from solution is called precipitation. Often the precipitate emerges as a suspension. (Precipitates can form when two soluble salts react in solution to form one or more insoluble products) Energy Levels - correct answer (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. As you go farther from the nucleus, electrons at higher energy levels have more energy. Electrons in the outermost energy level of an atom are called valence electrons Marquis Test - correct answer is commonly used for Ecstasy testing as MDMA turns the precipitate purple black. Cobalt thiocyanate is used to test for cocaine. The Cobalt is mixed with the questionable substance, then drowned in hydrochloric acid, doused in chloroform, and shaken. What is the relation between an atomic number and a mass number? - correct answer Atomic number is actually the number of protons in an atom while mass number is the number of nucleons i. e, number of protons plus the number of neutrons. Isotopes - correct answer are members of a family of an element that all have the same number of protons but different numbers of neutrons. Chemical Synthesis - correct answer the construction of complex chemical compounds from simpler ones. It is the process by which many substances important to daily life are obtained Decomposition - correct answer is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds. These reactions often involve an energy source such as heat, light, or electricity that breaks apart the bonds of compounds single-displacement reaction - correct answer is a type of chemical reaction where an element reacts with a compound and takes the place of another element in that compound Flame test - correct answer analytical procedure used in chemistry to detect the presence of certain elements, primarily metal ions, based on each element's characteristic emission spectrum. The color of flames in general also depends on temperature Precipitation reaction - correct answer In an aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution. The solid formed is called the precipitate organic compounds - correct answer is a substance that is added to a product, like food, to improve some qualities such as taste, smell, colour and texture. These substances can be both positive and negative f