HESI A2 SECRETS CHEMISTRY EXAM QUESTIONS

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HESI A2 SECRETS CHEMISTRY EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -67 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Absorption

Answer:

The process by which a substance is soaked up

Question 2: Cell

Answer:

A vessel containing two electrodes and an electrolyte that can act as an electrical conductor.

Question 3: Alkaline earth metal

Answer:

a member of group 2 of the periodic table. Ex calcium

Question 4: Atomic mass

Answer:

The mass of an atom measured in ____ mass units (amu). An _____ mass unit is equal to 1/12th of the atom of carbon-12. ______ mass is now more generally used instead of _____ weight. Ex the _____ mass of chlorine is about 35 amu

Question 5: Activated charcoal

Answer:

A form of carbon, made up of tiny crystals of graphite, which is made by heating organic matter in the absence of air. It is then processed further to increase its pore space and therefore its surface area. Its surface area is about 2000 m2/g. ________ ________ readily adsorbs many gases and it is therefore widely used as a filter ex. gas masks

Question 6: Change of state

Answer:

A change between two of the three states of matter, solid, liquid or gas. Ex. when water evaporates it changes from a liquid to a gaseous state

Question 7: Acid salt

Answer:

contains at least one hydrogen ion and can behave as an acid in a chemical reaction. ______ _______ are produced under conditions that do not allow complete neutralisation of the acid. Ex. sulphuric acid may react with a sodium compound to produce a normal sodium salt, sodium sulphate (Na2SO4), or it may retain some of the hydrogen, in which case it becomes the salt sodium hydrogen sulfate (NaHSO4)

Question 8: Charles Law

Answer:

The volume (V) of a given mass of gas at constant pressure is directly proportional to its absolute

temperature (T): V T

Question 9: Atomic structure

Answer:

The nucleus and the arrangement of electrons around the nucleus of an atom

Question 10: Catalyst

Answer:

A substance that speeds up a chemical reaction, but itself remains unaltered at the end of the reaction ex. copper in the reaction of hydrochloric acid with zinc

Question 11: Antacid

Answer:

A common name for any compound that reacts with stomach acid to neutralize it Ex sodium hydrogen carbonate, also known as sodium bicarbonate

Question 12: Atmospheric pressure

Answer:

The pressure exerted by the gases in the air. Units of measurement are kilopascals (kpa), atmospheres (atm), millimeters of mercury (mmHg) and Torr. Standard ______ pressure is 100 kpa, 1atm, 760 mmHg or 760 Torr

Question 13: Adsorption

Answer:

The process by which a surface adsorbs a substance. The substances involved are not chemically combined and can be separated. Ex. the ______ properties of activated charcoal

Question 14: Atomic weight

Answer:

A common term used to mean the average molar mass of an element. This is the mass per mole of atoms. Ex the atomic weight of chlorine is about 35g/mol.

Question 15: Antioxidant

Answer:

a substance that reacts rapidly with radicals therby preventing oxidation of some other substance

Question 16: Burette

Answer:

A long, graduated glass tube with a tap at one end. A burette is used vertically, with the tap lowermost.Its main use is as a reservoir for a chemical during titration

Question 17: Alkali metals

Answer:

A member of group 1 of the periodic table. Ex sodium

Question 18: Buffer (solution)

Answer:

a mixture of substances in solution that resists a change in the acidity or alkalinity of the solution when small amounts of an acid or alkali are added

Question 19: Chromatography

Answer:

A separation technique using the ability of surfaces to adsorb substances with different strengths. The substances with the least adherence to the surface move faster and leave behind those that adhere more strongly

Question 20: Celsius scale

Answer:

A temperature scale on which the freezing point of water is 0 degrees and the normal boiling point at standard atmospheric pressure is 100 degrees

Question 21: Ceramic

Answer:

A material based on clay minerals which has been heated so that it has chemically hardened

Question 22: Cation

Answer:

a positively charged ion. Ex calcium ion (Ca2+) ammonium ion (NH4+)

Question 23: Acid

Answer:

A substance that can give a proton to another substance. ____ are compounds containing hydrogen that can attack and dissolve many substances. ____ are described as weak or strong, dilute or concentrated, mineral or organic. An ___ in water can react with a base to form a salt and water (HCl)

Question 24: Amphoretic

Answer:

A metal that will react with both acids and alkalis. Ex aluminium metal

Question 25: Actinide series or actinide metals

Answer:

a series of 15 similar radioactive elements between actinium and lawrencium. They are transitional metals