term/question | definition/answer |
The space shuttle's solid rocket boosters use ammonium perchlorate and aluminum to create an explosive reaction. NH4ClO4 (s) + Al (s) Al2O3 (g) + HCl (g) + N2 (g) + H2O (g)
Which of the following statements correctly describes this reaction? | Aluminum is the reducing agent. |
What is the oxidation number of each phosphorus atom(P) in the compound calcium phosphite, Ca3(PO3)2 ? | +3 |
In the equation: 3Br2 +2 Ga ---> 2GaBr3 what is not true? | gallium is gaining electrons |
What is not en example of an oxidation reduction reaction? | CuSO4+2NaOH ------> Cu(OH)2+Na2SO4 |
For the reaction: N2 (g) + 3 H2 (g) ---><--- 2 NH3 (g) ^H = -92 kJ/mol explain the T and P conditions that would produce higher yield for the forward reaction. Explain in terms of Le Chateliers principle. | Temperature: The reaction is exothermic so it will take place at low temperatures.
Pressure: If you increase the pressure, it will favor the side with the least amount of moles. So in this case it would favor the product side. |
In 2 SO3 (g) ---><---2 SO2 (g) + O2 (g) ^ H = +197 kJ/mol what would cause the equilibrium position to shift to the right? | increase the volume. |
What change would not result in a shift of the equilibrium position to the left. 2A+B---><---- 3C | cooling the system |
In a chemical reaction, it is determined that the equilibrium constant is 0.213. What is a correct statement regarding this reaction? | there are more reactants than products at equilibrium |
When a reaction is reversible, eventually the rates of the forward and reverse actions will be equal. Which of the following best explains what this means? | the concentration of the reactants have become constant. |
What is the pH of a solution with a concentration of 1.8*10^-4 molar H3O+ | I put -log(1.8*10^-4) into my graphing calculator and got 3.744. |
If 45.0 mL of 0.25 M HCl is required to completely neutralize 25.0 mL of NH3, what is the concentration of the NH3 solution? Show all of the work needed to solve this problem.
HCl + NH3 ---> NH4Cl | 45*1/1000*0.025/1=0.001125
there are 25mL of NH3, so that is 0.25 liters 0.001125/0.025=0.4512M |
In the following reaction, what substance is acting as the Brønsted-Lowry acid?
NH3 + H2O----> NH4+ + OH- | H2O |
What cannot define a acid? | a substance that increases the hydroxide ion concentration of a solution |
What is not true of a strong base? | it must have a concentration above 1.0 M |
What solution will not neutralize a weak base solution of pyridine(C5H5N)? | ammonia |
What is the salt produced when sulfuric acid (H2SO4) reacts with potassium Hydroxide(KOH)? | K2SO4 |
What is the pH of a solution with a concentration of 2.4 × 10-5 molar H3O+? Show, or explain, the work used to solve this problem. | the pH would be 4.6
Work :
pH= -log (2.4*10^-5)
pH: 4.6 |
Predict which of the following would shift the equilibrium to the right in the following reaction.
C2G2+H2O---><---- CH3CHO | adding H2O to the system |
In terms of particles, concentration, and reaction rate, what you expect to happen when methane gas (CH4) and hydrogen sulfide gas (H2S) are sealed in a flask and reach a state of equilibrium. CH4 (g) +2 H2S (g) CS2 (g) + 4 H2 (g) (4 points) | 1.&2 react ,the concentration of the two begins to reduce. so does the reaction rate. As CS2 and H2 are created, they begin to react with 1&2 and create the reverse of what happened first. until the forward and backwards rate are the same. |
What would decrease the pH level of an acidic solution? | increasing the number of hydrogen ions |
What represents the correct neutralization reaction of hydrobromic acid and calcium hydroxide? | 2 HBr + Ca(OH) 2 ---> CaBr2 + 2 H2O |
What solution can be used to neutralize nitric acid? | Ca(OH)2 |
What is not true of bases? | Arrhenius bases are any substance that decreases the concentration of hydroxide ions. |
If the forward reaction goes close to completion and has a high yield, what is the expected value of the equilibrium constant (K)? (2 points) | K>1 |
What substance is acting as the Brønsted-Lowry base in the forward reaction below?
H2O + NH3 ----> NH4+ + OH- | NH3 |
What is the oxidation number of Nitrogen in HNO2? | +3 |
What is true of a basic solution at room temperature? | it has a greater concentration of hydroxide compared to hydronium ions |
Rusting is a chemical process that changed the strength and integrity of objects made of iron or iron alloys. Which of the following statements correctly describes the rusting process below? | oxygen was reduced over the course of this reaction |
In terms of particles, concentration, and reaction rate, what you expect to happen when ethene gas (C2H4) and water vapor are sealed in a flask and reach a state of equilibrium. 3/4 | the container is filled with C2H4 and H2O(g). This means the con. of the (g) is the same as their mol, and the con. of C2H5OH is 0. when it starts, mol. will be - from C2H4 and H2O to make 1 mol of C2H5OH. Once the equi. is reached, the reacti slows down. |
If 27.0 mL of Ca(OH)2 with an unknown concentration is neutralized by 32.40 mL of 0.185 M HCl, what is the concentration of the Ca(OH)2 solution? | Ca(Oh)2+2HCl---> 2H2O +CaCl2
Ca(OH)2(aq) + 2HCI(aq) --> CaCI2(aq) + 2H2O(l)
n(Ca(OH)2 = 1/2* n(HCI) = 1/2* 0.03240 L * 0.185 M = 0.003 mol
Ca(OH)2 = 0.003 mil/ 0.0270 L = 0.111 M |
What is the pH of a solution with a concentration of 3.6 × 10-5 molar H3O+? Show, or explain, the work used to solve this problem. | pH: -log (3.6*10^-5)
ph: 4.4 |
For the reaction below, describe the temperature and pressure conditions that would produce the highest yield of the forward reaction. Explain your answer in terms of Le Châtelier's principle. | To get the highest py you would need to decrease the temp as well as the pres. the LCP, is a new stress is app, it wants to find a way to relieve the stress. This will - some of the product ,make the system restore its lost material, make new particles. |
Give a detailed explanation of how you can use the laboratory technique of titration to determine the concentration of an acetic acid solution. 2/4 | put the known volume of the acid in a flask that has an indicator that changes color when the end point is reached,put the conc. of a base into a burette and record the volume of the base. Start the titrating then stop when the solution changes color. |
Give a detailed explanation of how you can use the laboratory technique of titration to determine the concentration of an acetic acid solution. (2/4) | You use the titrate,mix it with the acetic acid solution. keep adding the titrate until the acetic acid gains the color of what it would be when it becomes neutral, use the amount of titrate you added to find out the concentration of the acetic acid. |
What is true of an acidic solution at room temperature? | it has a pH value below 7 |
A chemical system at equilibrium is referred to as dynamic because what? | rates of the forward and reverse |
What is a definition of an Arrhenius acid? | a substance that increases the concentration of hydronium ions when dissolved in water |
When ammonia dissolves in h2o, hydrogen ions are transferred from the h2o to nh3 to form ammonium ions and hydroxide ions. This reaction can be seen below:H2O (l) + NH3 (aq) yields OH- (aq) + NH4 + (aq) What explain why nh3 is a base? | Brønsted-Lowry definition |
What reactions shows the formation of a hydronium ion? | H+ +H2O---> H3O+ |
What substance is acting as the Brønsted-Lowry base in the following reaction? HNO3+H2O--->H3O+ +NO3- | H2O |
What is an acid-base neutralization reaction? | HNO3+KOH----> KNO3+H2O |
What is the salt produced when barium hydroxide, Ba(OH)2, reacts with sulfuric acid(H2SO4)? | BaSO4 |
What is the concentration of an NaOH solution that requires 15.0ml of a 0.750M H2SO4 solution to neutralize 17.5 ml of NaOH? | 1.29 M |
What is a possible definition of a base? | a compound that is a hydrogen ion acceptor in an acid-base reaction |
What is a common property or characteristic of a base? | slippery feel |
what is true of a strong base? | it ionizes close to 100% in H2O |
What substance is acting as the Bronsted-Lowry acid in the forward reaction below?H2O +NH3---> NH4+ +OH- | H2O |
Discuss the difference between acids and bases | Acid- a compound that produces hydrogen ions in solution
base- a compound that produces hydroxide ions ins solution |
what is true of strong acids? | it ionizes close to 100% in an (aq) solution |
What are some properties of acids | sour taste, corrosive, react with active metal to produce hydrogen gas, are electrolytes. react with bases to produce salt and water. |
Why do some acids have a sour taste? | because some fruits have a weak acid. Lemons grapefruit, and oranges have citric acid while apples have malic acid. Aspirin contains acetylsalicylic acid. |
What are active metals and what happens when acid reacts with these metals? | Active metals are groups 1 and 2 on the periodic table. When acids react with the active metals, they undergo single -replacement reactions when they come in contact with certain acids thus creating hydrogen gas. |
How are acids electrolytes? | Aqueous solutions that contain acids are able to conduct an electric current because of the presence of electrolytes (ions) |
What happens when acids and bases react together? | When acids and bases react together, they produce water and a salt (ionic compound) as the products. This type of double-replacement reaction is called a neutralization reaction. |
What are some examples of bases? | household ammonia, sodium hydroxide, milk of magnesia, and aluminum hydroxide |
What do bases often do? | they often increase the concentration of hydroxide ions(OH-) when dissolved in water, and the hydroxide ion is an excellent hydrogen acceptor. Many bases are ionic metal hydroxides that ionize when they dissolve. |
What are some properties of bases | they have a bitter base, diluted basic solutions feel slippery and bases react with acids to produce salt and water. |