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# CHEM121 001 Final

### Chem flashcards for UNM 121 Final Exam

Question | Answer |
---|---|

The statement, "In a chemical reaction, matter is neither created nor destroyed" is called? | the Law of Conservation of Mass. |

Choose the pure substance from the list below. air, sea water, milk, sugar, lemonade | sugar |

Which of the following are examples of a chemical change? copper building materials develop a green patina over time a match burns ethanol evaporates Both A and B are examples of chemical change. All of the above | Both A and B are examples of chemical change. |

True/False: Potential energy is the energy associated with its movement. | False |

All of the following are SI base units of measurement, EXCEPT: second, mole, kelvin, gram, meter | gram |

If a solution has a temperature of 355 K, what is its temperature in degrees celsius? | 82 degrees celsius |

Determine the mass of an object that has a volume of 88.6 mL and a density of 9.77 g/mL. | 866 grams |

A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.79 g/mL, 1.81 g/mL, 1.80 g/mL, 1.81 g/mL. If the actual value for the density of the sugar solution is 1.80 g/mL, describe her results. | Her results are both precise and accurate. |

What answer should be reported, with the correct number of significant figures, for the following calculation? (965.43 × 3.911) + 9413.4136 | 13189 |

The mass number is equal to? | the sum of the number of protons and neutrons. |

Determine the number of protons, neutrons and electrons in the following: A) p+ = 29 n° = 36 e- = 36 B) p+ = 29 n° = 29 e- = 36 C) p+ = 29 n° = 36 e- = 29 D) p+ = 36 n° = 36 e- = 29 E) p+ = 36 n° = 29 e- = 36 | p+ = 29 n° = 36 e- = 29 |

Predict the charge that an ion formed from sulfur would have. | 2- |

Which of the following elements is an alkaline earth metal? | Mg |

Silver has an atomic mass of 107.868 amu. The Ag-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope? | 106.905 amu |

Calculate the mass (in g) of 1.9 x 1024 atoms of Pb. | 6.5 × 102 grams |

Which of the following contains BOTH ionic and covalent bonds? | CaSO4 |

What is the empirical formula for C4H10O2? | C2H5O |

Give the structure for sodium chlorate. | NaClO3 |

Write the name for Ca3(PO4)2. | calcium phosphate |

Give the formula for sulfurous acid. | H2SO3 |

What is the mass of 9.44 × 1024 molecules of NO2? The molar mass of NO2 is 46.01 g/mol. | 721 grams |

Write a balanced equation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate. | Al(C2H3O2)3 (aq) + (NH4)3PO4 (aq) → AlPO4 (s) + 3 NH4C2H3O2 (aq) |

Identify an amine. | CH3CH2NH2 |

How many moles of nitrogen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g) | 0.290 mol N2 |

How many moles of LiI are contained in 258.6 mL of 0.0296 M LiI solution? | 7.65 × 10-3 mol |

Determine the concentration of a solution prepared by diluting 25.0 mL of a stock 0.188 M Ca(NO3)2 solution to 150.0 mL. | 0.0313 M |

Identify HCl. | strong electrolyte, strong acid |

Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Na2CO3 and HCl are mixed. | 2 H+(aq) + CO32-(aq) → H2O(l) + CO2(g) |

A gas occupies 3.33 L at 2.23 atm. What is the volume at 2.50 atm? | 2.97 L |

A syringe contains 0.65 moles of He gas that occupy 750.0 mL. What volume (in L) of gas will the syringe hold if 0.35 moles of Ne is added? | 1.2 L |

A gas is at 35.0°C and 4.50 L. What is the temperature at 9.00 L? | 343 C |

A sample of gas initially has a volume of 859 mL at 565 K and 2.20 atm. What pressure will the sample have if the volume changes to 268 mL while the temperature is increased to 815 K? | 10.2 atm |

Calculate the temperature, in K, of 2.20 moles of gas occupying 3.50 L at 3.30 atm. | 64.0 K |

Place the following gases in order of increasing density at STP. N2, NH3, N2O4, Ar | NH3 < N2 < Ar < N2O4 |

A mixture of N2, O2 and Ar have mole fractions of 0.25, 0.65, and 0.10, respectively. What is the pressure of N2 if the total pressure of the mixture is 3.9 atm? | 0.98 atm |

Rank the following in order of decreasing rate of effusion. F2, SF6, CO, Kr | CO > F2 > Kr > SF6 |

Calculate the change internal energy (ΔE) for a system that is giving off 45.0 kJ of heat and is performing 855 J of work on the surroundings. | -45.9 kJ |

Determine the specific heat capacity of an alloy that requires 59.3 kJ to raise the temperature of 150.0 g alloy from 298 K to 398 K. | 3.95 J/g°C |

Identify what a bomb calorimeter measures. | measures ΔE for combustion reactions |

Calculate the change in internal energy (ΔE) for a system that is absorbing 35.8 kJ of heat and is expanding from 8.00 to 24.0 L in volume at 1.00 atm. (Remember that 101.3 J = 1 L∙atm) | +34.2 kJ |

A 4.98 g sample of aniline (C6H5NH2, molar mass = 93.13 g/mol) was combusted in a bomb calorimeter with a heat capacity of 4.25 kJ/°C. If the temperature rose from 29.5°C to 69.8°C, determine the value of ΔH°comb for aniline. | -3.20 × 103 kJ/mol |

Which of the following processes is endothermic? | an atom absorbs a photon |

According to the following reaction, how much energy is required to decompose 55.0 kg of Fe3O4? The molar mass of Fe3O4 is 231.55 g/mol. Fe3O4(s) → 3 Fe(s) + 2 O2(g) ΔH°rxn = +1118 kJ | 2.66 × 105 kJ |

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 2 S(s) + 3 O2(g) → 2 SO3(g) ΔH°rxn = ? Given: SO2(g) → S(s) + O2(g) ΔH°rxn = +296.8 kJ 2 SO2(g) + O2(g) → 2 SO3(g) ΔH°rxn = -197.8 kJ | -791.4 kJ |

Choose the thermochemical equation that illustrates ΔH°f for Li2SO4. | 2 Li(s) + 1/8 S8(s, rhombic) + 2 O2(g) → Li2SO4(s) |

Place the following types of electromagnetic radiation in order of decreasing energy. ultraviolet light, radio waves, microwaves | ultraviolet light > microwaves > radio waves |

Which of the following occur as the wavelength of a photon increases? | the frequency decreases |

Determine the velocity of a marble (m = 8.66 g) with a wavelength of 3.46 × 10-33 m. | 22.1 m/s |

Choose the transition (in a hydrogen atom) below that represents the absorption of the shortest wavelength photon. | n = 1 to n = 2 |

What value of l is represented by a d orbital? | 2 |

Choose the one set of quantum numbers that does not contain an error. A) n = 4, l = 0, ml =-1 B) n = 3, l = 1, ml = -2 C) n = 5, l = 3, ml =-3 D) n = 4, l = 4, ml =0 E) n = 3, l = 2, ml =+3 | C |

Which of the following quantum numbers describes orbital shapes? | angular momentum quantum number |

Identify the correct values for a 3p sublevel. | n = 3, l = 1, ml = 0 |