General Questions and Answers

Consider the following reactions i. CH4(g) + 2O2(g) = CO2(g) + 2 H₂O(1) ii. MgCO3(s) = MgO(s) + CO2(g) iii. U(s) + 3 F2(g) = UF6(8) The signs of AS for each of these reactions are respectively a. None of the other answers are correct b. +,-,- C.-, +,- d.-, -, +

Thermal energy is... Potential energy stored within neutrons and protons Potential energy associated with an object's position The movement of atoms and molecules The movement of electrons

Based on the spectrochemical Series CI- <H₂O < NH3 < CN- < CO Which of the following octahedral complexes is most likely to absorb electromagnetic radiation of red light? a. [Cu(CO)4]²+ b. [Cu(Cl)4]²- c. [Cu(NH3)4]²+ d. [Cu(CN)41²- e. [Cu(H₂0)4]²+

If 140 g of NaNO3 will dissolve in 100 g of water at 80°C, how many grams will dissolve in 250 g water?

Ammonia gas reacts with oxygen gas to produce nitrogen dioxide gas and water vapor. Write a balanced chemical reaction. Calculate the enthalpy: Is this reaction endothermic or exothermic? exothermic kJ/mol

At 40°C, how much KNO3 can be dissolved in 300 g of water?

In an exothermic reaction, the energy stored in the chemical bonds of the reactants is equal to the energy stored in the bonds of the products. greater than the energy stored in the bonds of the products. less than the energy stored in the bonds of the products. less than the heat energy released as a result of the reaction.

Which of the following describe(s) the following reaction? Choose all that apply. bombardment reaction potential chain reaction beta decay reaction alpha decay reaction fission reaction

Use the References to access important values if needed for this question. Transuranium elements are artificial and may be prepared by a fusion process in which heavy nuclei are bombarded with light ones. Complete the equation for the following fusion reaction by filling in the nuclear symbol for the missing product 239 Pu + He 94

With a partner, use the target vocabulary to complete this article on the impact of global climate change. annual compatible contributed erosion polar bears will (8) impact process traced ultimately Today there are 20,000 to 25,000 polar bears worldwide. This represents a decline of 21% over the last 20 years that can be directly (1) to global climate change. As the average (2) ocean temperature in the Arctic rises, the bear population declines. The bears' way of life is not with a warm climate because they depend on sea ice of global climate change (3) for summer hunting. The (4) has caused an (5) of the polar bear environment. It has (6) to weight loss in the males, falling reproduction rates in the females, and lower survival rates among newborn cubs. If the overall warming of global climate change continues at its present rate, the disappear.

Which of the following statements is inaccurate? Select the best answer. Deception involves purposely misleading experiment participants in order to maintain the integrity of the experiment. Sometimes deception is necessary to prevent participants' knowledge of the exact research question from affecting the results of the study Researchers do not have to share information with participants about how the data collected will be used.

Which of the following is a correct balanced equation for the reaction described here? Sodium reacts with lithium oxide to produce sodium oxide and lithium. Na+ Li₂O → Na₂O + Li Na₂ + Li₂O → Na₂O + Li₂ 2Na+ Li₂O → Na₂O + 2Li Na+LIO → NaO + Li

Order the steps required to predict the volume (in mL) of 0.100 M sodium carbonate needed to produce 1.00 g of calcium carbonate. There is an excess of calcium chloride. Step 1 Convert the volume of sodium carbonate solution required from liters to milliliters Step 2 Compare moles of calcium carbonate to moles of sodium carbonate based on balanced equation to calculate moles of sodium carbonate requ Step 3 Convert mass of calcium carbonate to moles of calcium carbonate Step 4 Compute the volume of sodium carbonate solution required

2C₂H6(g) +7O₂(g) 4CO₂(g) + 6H₂O(g) Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 1.72 moles of C₂H6(g) react at standard conditions.

The process by which air flows from one location in the atmosphere to another is driven by which type of thermal energy transfer? convection equilibrium radiation chicken conduction

The equilibrium constant, Kp, for the following reaction is 55.6 at 698 K: H₂(g) + I₂(g) 2HI(g) Calculate the equilibrium partial pressures of all species when H₂ and I₂, each at an intitial partial pressure of 1.54 atm, are introduced into an evacuated vessel at 698 K.

Ca3P2(s) + H₂O(l)→ Ca(OH)2 (aq) + PH3(g) Express your answer as a chemical equation. Identify all of the phases in your answer.

If 0.063 mol of hydrochloric acid (HCI) is mixed with 0.063 mol of sodium hydroxide (NaOH) in a "coffee cup" calorimeter, the temperature of 4.8 g of the resulting solution increases from 25.0°C to 33.0°C. Given that the energy released is 1.8 × 10¹ cal when the specific heat of the resulting solution is 1.00 cal/g °C, use a conversion factor to convert the energy released to joules (J).

When boron hydrides burn in air, the reactions are very exothermic. B₁0H₁4 (8) burns in air giving B₂O3(s) and H₂O(g) in the reaction: B10H14 (s) + 11 O₂(g) → 5 B₂O3(s) + 7 H₂O(g) Calculate the enthalpy of combustion for B10H₁4 (8) (ΔfH' = -28.9 kJ/mol). The enthalpy of formation of B₂O3(s) and H₂O(g) are-1271.9 kJ/mol and -241.8 kJ/mol, respectively.

If the specific heat of an unknown substance is found to be 0.100 J. How much energy would it take to heat a 100g sample of the unknown substance by 2 degrees celsius? 20 J 1000 J 100 J 200 J

In the Reaction: CuCl2 + 2 NaNO3 → Cu(NO3)2 + 2 NaCl If 17.2 grams of copper (II) chloride, CuCl2, reacts with 22.6 grams of sodium nitrate, NaNO3, how many grams of sodium chloride, NaCl, will be produced? (4 points) Molar mass of CuCl2 = 134.45 g/mol Molar mass of NaNO3 = 85.00 g/mol Molar mass of NaCl = 58.44 g/mol Answers: 17.2 grams CuCl2 = 22.6 grams NaNO3 = g NaCl g NaCl What is the Limiting Reactant?

Consider the following situations: 1. A person touches a cold piece of metal II. A lamp shines on a table. III. A person stirs a hot mug of coffee tea with a spoon. IV. A bag of frozen peas sits inside your freezer. In which of these situations is heat transfer taking place? I, II, III and IV I, II, and III only II and IV only I, III, and IV only I and III only

Your feet feel warmer on a rug than on a tile floor because: both items are the ambient temperature in the room, but the rug is an insulator that totally blocks the transfer of heat from your skin into the floor the rug has a much lower density than the tile, so the molecules needed for conduction are spread out too far to function well the tile's higher density allows it to transfer thermal units of cold into your skin at a faster rate, increasing the feeling of heat loss both items are the ambient temperature in the room, but the tile is a better conductor of heat so the transfer of body heat into the floor is faster than the rug

In the Reaction: Pb(NO3)2 + 2 KI → Pbl2 + 2 KNO3 How many grams of lead (II) iodide, Pbl2, is produced from 82.7 grams of potassium iodide, KI? Answer: g Pbl2 (ONLY include number value, DO NOT include units or letters! Round to two decimal places.)

Think about the autohydrolysis of water: 2 H₂O(1) H₂O(g) + OH(aq) At 0°C, K = 1.26 x 10-15 At 25°C, K = 1.00 x 10-14 Is the autoionization of water endothermic or exothermic? Briefly explain, based on these data.

1. The wind system that brings winter storms to the west coast of North America is : a. The polar easterlies. b. The westerlies. c. The trade winds. d. The southeasterlies. a d b C

Consider the following reaction C3H8 +502 → 3CO2 + 4H2O a. When 154.54 grams of C3Hg reacts with 98.56 grams of O2, how many grams of CO2 are formed?

Show your work: a) Balance the equation: _Zn + HCI --> __ZnCl2 +H2 b) Based upon the equation above how many moles of ZnCl2 will be produced from 5.06 moles of Zn?

What is the correct IUPAC name for Al2(SO3)3?

The reaction for the decomposition of ammonía can be written as shown below. If a student starts with 21.7 g of ammonia how many grams of hydrogen gas will be produced by the reaction? 2NH3 N2 + 3H2 2.55 g 1.28 g 3.85 g 32.5 g

The speed of light is 2.99 x 108 m/s. Change this to feet-per-minute (ft/min). 1 foot = 0.3048 m, 60.000 sec (exact) = 1 min, Unrounded Answer = 5.88583 x 10¹0 ft/min Hint: To enter scientific notation on your calculator use your EXP or EE button. For example, type 2.99 (EE) 8 or 2.99 (EXP) 8. This is a great chance to ask for help if you don't know how to use this function on your calculator.

When butanol (C4H,OH) is burned in oxygen, CO₂ and H₂O are the products. What is the coefficient in front of the O₂ in the balanced equation (using only whole numbers and the lowest whole number ratio)?

Calcium carbide, CaC₂, reacts with water to form acetylene. CaC₂(s) + 2H₂O(1)-C₂H₂(g) + Ca(OH)₂(s) a. How many grams of water are needed to react with 45 g of calcium carbide? 5 points b. How many grams of CaC₂ could make 236 g C₂H₂? 5 points c. If 88.3 g Ca(OH)2 are formed, how many grams of water reacted? 5 points

Heat is the an object contains. amount of kinetic energy No answer text provided. amount of potential energy total amount of energy

Which scientist determined the charge of the electron? A) John Dalton B) J. J. Thomson C) Robert Millikan D) Ernest Rutherford E) James Chadwick

A white powder mixture is placed into water. Some of the powder sinks to the bottom of the container, some rises to the top. The separation of the powder mixture is an example of A) a chemical change B) a chemical reaction C) a physical change D) an extensive property

A sample of hellum gas has a volume of 0.180 L, a pressure of 0.800 atm, and a temperature of 29 °C. At what temperature (°C) will the helium have a volume of 90.0 mL and a pressure of 3.20 atm (n remains constant)?

All of the following statements concerning acid-base buffers are true EXCEPT A buffers are used as colored indicators in acid-base titrations. B buffers are resistant to pH changes upon addition of small quantities of strong acids or bases. C the pH of a buffer is close to the pKa of the weak acid from which it is made. D buffers contain appreciable quantities of a weak acid and its conjugate base.

Which of the following gases consist of molecules containing three different elements?

If 2.4 x 10 raised to the power 1 mol oxygen are used, then how many moles of water are produced? The quantity is the double because every oxygen molecule contains two oxygen atoms and there is only one oxygen atom in water The quantity is the same because the coefficients are the same in the balanced chemical reaction It is not possible to answer this question because not enough information is provided The quantity is the halved because every oxygen molecule contains two oxygen atoms and there is only one oxygen atom in water

Which of the following reactions represent the dissociation of a strongelectrolyte in water NH3(g) + H₂O() -> NH4OH(aq) CH3OH(l) CH₂OH(aq) K2SO4(s) → 2K+ (aq) + SO4²- (aq) C₂H5OH() → C₂H5OH (aq)

The atomic mass of germanium (Ge) on the periodic table is 72.630 amu. Which of the following best explains why the atomic mass is a fraction between 72 and 73? A) The presence of different isotopes B) The presence of different isomers. C) The formation of different ions. D) The presence of different allotropes. E) The presence of different amounts of protons.

Which of the following is a precipitation reaction? I. N2H4 + 2H2O2 → N2 + 4H₂O II. ZnCl₂ (aq) + H₂ SO4 (aq) → ZnSO4 (aq) + HCl (aq) III. Ca(OH)2(s) Cao (s) + H₂O(l) IV. Mg(NO3)2(aq) + K₂SO4 (aq) → MgSO4 (s) + 2KNO(aq)

Select the BEST answer from the choices below. Identify in which change is S₂O3 oxidized? S2O3 --> S2O S203 --> S2 S2O3 --> S2O4 S2O3 --> SO

How can you identify a pure compound? A pure compound has definite melting and boiling points. A pure compound has side effects. A pure compound has a range of melting and boiling points.

Select the BEST answer from the choices below. A chemical reaction in which the products can react to re-form the reactants is called a reaction. two-way reversible isothermic permeable

Which of the following pairs represent isotopes? A) 28Si and 28 Si4+ B) 28Si and 28AI C) 28Si and 2⁹ Si D) 28Si and 28 Si4- E) 28Si4+ and 28 Al³+

Select the BEST answer from the choices below. The amount of heat lost by hot chocolate is equal to the amount of heat gained by the surroundings. What is the process called? Thermal energy Thermal equilibrium Algor mortis Heat

What is the SI unit of energy? calorie degree Kelvin degree Celsius joule

If 1.8 x 10 raised to the power 2 moles of glucose are provided, how many moles of carbon dioxide will be produced? * 10.8 mol carbon dioxide 11 mol carbon dioxide 1.1 x 10 raised to the power 3 mol carbon dioxide 3.0 x 10 raised to the power 1 mol carbon dioxide