Chemistry final exam review 2025

How many valence electrons are in an atom of chlorine? - correct answer-7 How many valence electrons does aluminum have? - correct answer-3 Define reaction rate - correct answer-the decrease in concentration of reactants or the increase in concentration of products with time. How does increasing temperature affect the rate of reaction? - correct answer increasing temperature causes the kinetic energy to increase. Thus, molecules are moving faster and colliding more frequently. This causes the rate of reaction to incrase. If i decrease the concentration of reactant, what happens to the rate of reaction? - correct answer-decreasing concentration leads to less reactants available for collision. Therefore, reaction rate decreases. How does surface area influence reaction rate? - correct answer-by increasing the surface area of reactant molecules, we are increasing the space or point of contact that these molecules have available to interact. This causes an increase in the rate of reaction. How does a catalyst speed up a chemical reaction? - correct answer-a catalyst speeds up a chemical reaction by finding an alternate pathway with a lower activation energy. Define activation energy. - correct answer-the energy required to start a chemical reaction. Define equilibrium. - correct answer-equilibrium is established when the rate of the forward reaction is equal to the rate of the reverse reaction. Is energy absorbed or released in an endothermic reaction? - correct answer-absorbed. What is the sign of delta h for an exothermic reaction? - correct answer-exothermic reactions release energy. The sign of delta h is negative. When you touch a flask and it feels hot, is this an endothermic or exothermic process? - correct answer-exothermic; heat is being given off. Define specific heat capacity. - correct answer-the amount of heat required to raise 1g of a substance to 1 degrees celsius. Q=mc(delta)t ; what does "q" stand for? - correct answer-heat (kj) CHEM Q=mc(delta)t ; what does "c" stand for? - correct answer-specific heat capacity (j / g degrees c) What is a hydrogen ion donor called? - correct answer-an acid. What is a hydrogen ion acceptor called? - correct answer-a base. Feels slippery; acid or base? - correct answer-base. Tastes sour; acid or base? - correct answer-acid. Tastes bitter; acid or base? - correct answer-base. Ph 7 ; acid, base, or neutral? - correct answer-acid Ph 7 ; acid, base, or neutral? - correct answer-base Define neutralization. - correct answer-when an acid reacts with a base to form water and a salt. Ph = 7. Soap; acid or base? - correct answer-base (tastes bitter) Ammonia, acid or base? - correct answer-base (drain cleaners are bases). Lemonade; acid or base? - correct answer-acid (tastes sour) Define solute. - correct answer-the part of the solution in less amount. Define solvent. - correct answer-the part of the solution in greater amount. (hint: solvent is a bigger word than solute) How many atoms are in 1 mole? - correct answer-1 mole = 6.02 x 10^23 atoms/molecules What is the volume occupied by 1 mole of a gas at stp? - correct answer-1 mole of gas at stp = 22.4 l Define stp. - correct answer-pressure = 1 atm or 101.3 kpa Temperature = 0 degrees celsius or 273 k What is the temperature at absolute zero? - correct answer-0 k (all molecular motion stops) CHEM CHEM CHEM What causes gas pressure? - correct answer-gas molecules are constant motion and collide with the walls of their containers and with the surfaces that they come into contact with. This collision causes pressure. Equal volumes of gases at stp have equal _____. - correct answer-moles. What is 25 degrees celsius in kelvins? - correct answer-(kelvin = celsius + 273) Answer: 298k What is 98k in degrees celsius? - correct answer-(celsius = kelvin - 273) Answer: -175 degrees celsius What is the symbol for an alpha particle? - correct answer-4 he 2 What is the symbol for a beta particle? - correct answer-0 b -1 Mg + 2 hno3 --- mg(no3)2 + h2 If i start this reaction with 40.0 grams of magnesium and an excess of nitric acid (hno3), how many grams of hydrogen gas will i produce? - correct answer-3.3 g h2 C2h4 + 3 o2 ---- 2 co2 + 2 h2o If you start with 45 grams of ethylene (c2h4), how many grams of carbon dioxide will be produced? - correct answer-141.4 g co2 Balance the equation: H2 + o2 ----- h20 - correct answer-2 h2 + o2 ---- 2 h20 Balance the equation: C3h8 + o2 --- co2 + h2o - correct answer-1 c3h8 + 3 o2 --- 5 co2 + 4 h2o Find the molar mass of al2(so4)3 - correct answer-342 g/mol Which of the following has the greatest freedom of movement: solids, liquids, gases? - correct answer-gases Identify the following as a metal, semimetal, transition metal, or nonmetal: H, c, k, fe, si - correct answer-h - nonmetal CHEM CHEM C - nonmetal K - metal Fe - transition metal Si - semimetal Are noble gases reactive? - correct answer-no! They have a full octet of electrons. They do not want to react with anything. Given the reaction at equilibrium: 1/2 n2 (g) +1/2 o2 (g) + 21.6 kcal --- no (g) What will happen if temperature is increased? - correct answer-increasing temperature means heat is being added more to the left side (think mud slide). The reaction will shift right to form more no. Is fusion an endothermic or exothermic process? - correct answer-endothermic (going from solid -- liquid). Think about phase change diagram. Is condensation an endothermic or exothermic process? - correct answer-going from gas --- liquid. This is exothermic. Is vaporization endothermic or exothermic? - correct answer-going from liquid --- gas. This is endothermic. Is solidification endothermic or exothermic? - correct answer-going from liquid --- solid. This is exothermic. Draw the lewis dot structure for an atom of neon in its ground state. - correct answer-.. : ne : .. Draw the lewis dot structure for carbon. - correct answer-. . C . . Draw the lewis dot structure for fluorine. - correct answer-. : f : .. You have an acid that dissociates partially in solution. Is this a strong or weak acid? - correct answer-weak acids dissociate partially. Strong acids and ba