HESI A2 CHEMISTRY LATEST UPDATE 2021 WITH CORRECT ANSWERS GRADED A+

1. What are all metric measurements composed of? A. Metric prefix and a basic unit of measure B. A significand and a metric prefix C. A metric prefix and a coefficient D. A coefficient and a significand 2. What is the most commonly used temperature scale in the scientific community? A. Fahrenheit B. Celsius or Centigrade C. Kelvin D. English temperature method 3. The nucleus of an atom contains or is made up of which of the following? A. Protons and electrons B. Protons only C. Protons and neutrons D. Neutrons and electrons 4. What is an atom that has a positive charge called? A. A cathode B. A cation C. An anode D. An anion 5. In the periodic table, what are the rows called? A. Groups B. Moles C. Columns D. Periods 6. What is the atomic number? A. Number of neutrons B. Number of protons C. Number of electrons D. Number of isotopes 7. Which of the following describes the atomic mass? A. Mass of protons and electrons B. Mass of neutrons and electrons C. Average mass of that element’s isotopes D. Number of moles in a solution 8. Chemical equations are written in which manner? A. Product → Reactants B. Reactants → Products C. Reactants + Reactants D. Products + Reactants 9. What is the charge on potassium in the compound KCl? A. −1 B. +1 C. −2 D. +2 10. A catalyst is a substance that accelerates a reaction by which of the following? A. Adding energy to the overall reaction B. Increasing the amount of energy needed for the reaction to occur C. Finding an alternate pathway for a reaction that requires less energy D. Speeding up the overall reaction process 11. Percent concentration of a solution is expressed as which of the following? A. 100 parts per 100 dL B. Parts per 100 parts C. Parts of moles D. Moles per 100 parts 12. What will one liter of a one molar solution of any element contain? A. The atomic mass in grams of that element B. The atomic number in grams of that element C. The atomic mass in liters of that element D. The atomic number in liters of that element 13. Chemical bonding is the bonding of which of the following? A. One atom to another atom B. One mole to another mole C. A proton to an electron D. One cation to another cation 14. Which of the following describes an ionic bond? A. It shares electrons. B. It does not share electrons. C. It is sometimes called a covalent bond. D. It is the strongest of all chemical bonds. 15. The reaction 2C2H6 + 7O2 → 4CO2 + 6H2O has a ratio of 2 parts ethane (C2H6) and 7 parts oxygen (O2). How many parts of ethane (C2H6) will be needed to react with 21 parts of oxygen (O2)? A. 3 parts of ethane C2H6 B. 6 parts of ethane C2H6 C. 9 parts of ethane C2H6 D. 14 parts of ethane C2H6 16. What is the concentration of 58.5 g of NaCl in 2 L of solution (atomic weights of each element are as follows: Na = 23 g/mol, Cl = 35.5 g/mol)? A. 0.5 mol NaCl B. 0.75 mol NaCl C. 1 mol NaCl D. 2 mol NaCl