N/A - Exam Exam Answers

Which indicates the energy that must be absorbed to initiate the reaction?

Which statement accurately describes this graph?

Consider the balanced equation. cap n sub 2 cap h sub 4 plus 2 cap h sub 2 cap o sub 2 ce bond right arrow cap n sub 2 plus 4 cap h sub 2 cap o What are the mole ratios of hydrazine open paren cap n sub 2 cap h sub 4 close paren to hydrogen peroxide open paren cap h sub 2 cap o sub 2 close paren and hydrazine to water?

Which line indicates a higher reaction rate?

What is the percentage concentration by mass of a solution that contains 0 point 0 9 8 kilograms of cap h sub 2 SO sub 4 in 500 point 0 g of cap h sub 2 cap o ? Use mass percent is equal to mass of solute over mass of solution times 100

Which statement accurately describes this graph?

A sample of water is taken and kept in a beaker in a freezer at a constant temperature of 0°C If the system is at dynamic equilibrium, which of these statements is true?

What is the equilibrium constant for the reaction at this temperature?

Consider the following reversible reaction. cap c times s plus cap o sub 2 times g long left right arrow CO sub 2 times g What is the equilibrium constant expression for the given system?

Which statement best describes the diagram?

A sample of propane open paren cap c sub 3 cap h sub 8 close paren has a mass of 0 point 4 7 g The sample is burned in a bomb calorimeter that has a mass of 1 point 3 5 0 kilograms and a specific heat of 5 point 8 2 the fraction with numerator cap j and denominator open paren g times degree cap c close paren How much energy is released by the reaction if the temperature of the calorimeter rises by 2 point 8 7 times degree C ? Use q is equal to m cap c sub p triangle cap t

The balanced equation shows the formation of ethane open paren cap c sub 2 cap h sub 6 close paren cap c sub 2 cap h sub 2 plus 2 cap h sub 2 rightarrow cap c sub 2 cap h sub 6 How many moles of hydrogen are needed to produce 13 point 7 8 mol of ethane?

A mixture of three noble gases has a total pressure of 1 point 2 5 atm. The individual pressures exerted by neon and argon are 0 point 6 8 atm and 0 point 3 5 atm, respectively. What is the partial pressure of the third gas, helium? Use cap p sub cap t is equal to cap p sub 1 plus cap p sub 2 plus cap p sub 3 plus dot dot dot cap p sub n

Which is the molar mass of cap h sub 2 cap o ?

The main component of smog is NO sub 2 times g Smog is a product that is formed through this series of intermediate chemical reactions. N_2⁡(g)+​O_2⁡(g)→2NO(g) 2NO(g)+​O_2⁡(g)→2⁢NO_2⁢(g) NO_2⁢(g)→light+​NO(g)O(g) O_2⁡(g)+​O(g)→O_3⁡(g) NO(g)+​O_3⁡(g)→NO_2⁢(g)+​O_2⁡(g) What is the overall chemical equation for smog after the above intermediate reactions are combined?

A chemical reaction between cap x and cap y forms cap c according to the given reaction. The data for three trials to measure the rate of this reaction are also given. cap x plus cap y rightarrow cap c Trial cap x times cap m cap y times cap m Initial Rate open paren cap m over s close paren 1 0 point 0 1 0 point 0 1 5 7 point 8 3 times 10 to the negative 5 power 2 0 point 0 1 0 point 0 3 0 3 point 1 3 times 10 to the negative 4 power 3 0 point 0 2 0 point 0 1 5 1 point 5 7 times 10 to the negative 4 power What is the rate law for this reaction?

A sample of an unknown substance has a mass of 0 point 1 5 8 kilograms If 2 comma 510 point 0 cap j of heat is required to heat the substance from 32 point 0 times degree C to 61 point 0 times degree C , what is the specific heat of the substance? Use q is equal to m cap c sub p triangle cap t

Reactant cap p contains 50 cap j of energy, and reactant cap q contains 35 point 3 cap j of energy. The reactants combine to form product PQ , which contains 104 cap j of energy. What is the energy transformation?

What is a common use of bases?

Which is a characteristic of a Lewis base?

The reaction of a Lewis acid with a Lewis base would most likely be accompanied by an increase in which item?

The chemical equation shows the combustion of methane open paren CH sub 4 close paren CH sub 4 plus 2 cap o sub 2 rightarrow CO sub 2 plus 2 cap h sub 2 cap o The molar mass of oxygen gas open paren cap o sub 2 close paren is 32 point 0 0 g over mol The molar mass of carbon dioxide open paren CO sub 2 close paren is 44 point 0 1 g over mol What mass of CO sub 2 , in grams, will form when 8 point 9 4 g cap o sub 2 completely react?

What does the symbol open paren negative triangle cap h sub fus close paren indicate in a phase change?

If the base-dissociation constant, cap k sub b , for a substance is 4 point 3 times 10 to the negative 10 power , what does this tell you about cap k sub A ? Use cap k sub A cap k sub b is equal to cap k sub w

Pure water at 25 times degree C

Look at the reaction. cap h sub 2 SO sub 4 A q plus Mg times s rightarrow MgSO sub 4 times A q plus cap h sub 2 of g Which substance is the acid in the reaction?

Which value is most likely to be the pH of a salt solution that is formed by the reaction of a weak acid and a strong base?

A beam of light passes though a liquid in a test tube without scattering. Which type of mixture is most likely in the test tube?

A stock solution is made by dissolving 66 point 0 5 g of open paren NH sub 4 close paren sub 2 SO sub 4 in enough water to make 250 milliliters of solution. cap A 10 point 0 mL sample of this solution is then diluted to 50 point 0 milliliters Given that the molar mass of open paren NH sub 4 close paren sub 2 SO sub 4 is 132 point 1 g/mol , what is the concentration of the new solution? Use cap m sub i cap v sub i is equal to cap m sub f cap v sub f and molarity is equal to moles of solute over liters of solution

Which is the first step in the dissolving process?

Ca OH sub 2 is added to a large beaker of water. How is the solution different from the original water?

A solar panel combines multiple photovoltaic cells. Which type of energy is used to power a solar panel?

Which best describes the function of a centrifuge?

Consider these intermediate chemical equations. cap p sub 4 times s plus 6 Cl sub 2 g rightarrow 4 PCl sub 3 g triangle cap h sub 1 is equal to negative 2 comma 439 kJ 4 PCl sub 5 g rightarrow cap p sub 4 times s plus 10 Cl sub 2 g triangle cap h sub 2 is equal to 3 comma 438 kJ What is the enthalpy of the overall chemical reaction PCl sub 5 times g rightarrow PCl sub 3 times g plus Cl sub 2 times g ?

The initial temperature of a bomb calorimeter is 28 point 5 0 times degree C When a chemist carries out a reaction in this calorimeter, its temperature decreases to 27 point 4 5 times degree C If the calorimeter has a mass of 1 point 4 0 0 kilograms and a specific heat of 3 point 5 2 the fraction with numerator cap j and denominator open paren g times degree cap c close paren , how much heat is absorbed by the reaction? Use q is equal to m cap c sub p triangle cap t

The enthalpy of formation of water is negative 285 point 8 kJ over mol What can be inferred from this statement?

Magnesium reacts with hydrochloric acid HCl according to this equation. Mg times s plus 2 HCl aq rightarrow MgCl sub 2 times aq plus cap h sub 2 of g How many milliliters of hydrogen gas are produced by the reaction 0 point 0 2 0 mol of magnesium with excess of hydrochloric acid at STP? Make sure to use the correct number of significant digits.

Two cups of coffee, one that is at 10°C and one that is at 20°C , are mixed. Which statement about the temperature of the mixture is correct?

A student requires 2 point 0 0 liters of 0 point 1 0 0 cap m NH sub 4 NO sub 3 from a 1 point 7 5 cap m NH sub 4 NO sub 3 stock solution. What is the correct way to get the solution? Use cap m sub i cap v sub i is equal to cap m sub f cap v sub f

The chemical equation shows the burning of magnesium Mg with oxygen open paren cap o sub 2 close paren to form magnesium oxide MgO 2 Mg plus cap o sub 2 rightarrow 2 MgO The molar mass of cap o sub 2 is 32 point 0 g over mol What mass, in grams, of cap o sub 2 is required to react completely with 4 point 0 0 mol of Mg ?

Butane cap c sub 4 cap h sub 10 g , Δ⁢H_f=−125.7 , combusts in the presence of oxygen to form CO sub 2 times g , Δ⁢H_f=−393.5kJ/mol , and cap h sub 2 cap o g , Δ⁢H_f=−241.82 in the reaction: 2 cap c sub 4 cap h sub 10 g plus 13 cap o sub 2 g rightarrow 8 CO sub 2 g plus 10 cap h sub 2 cap o g What is the enthalpy of combustion, per mole, of butane? Use Δ⁢H_rxn=∑(Δ⁢H_f_1p⁢r⁢o⁢d⁢u⁢c⁢t⁢s)−∑(Δ⁢H_f_1r⁢e⁢a⁢c⁢tan⁡t⁢s)

Consider the rate law below. cap r is equal to k cap A cap b squared What effect does doubling the concentration of each reactant have on the rate?

A solution of sulfuric acid has a concentration of 0 point 0 9 8 0 g over cap l If the density of the acid is 1 point 8 4 g over mL , what is the concentration in ppm ? Use ppm is equal to mass of solute over mass of solution times 10 to the 6th power

The expression was formed by combining different gas laws. cap v proportional to n cap t over cap p Which law was used to determine the relationship between the volume and the number of moles in this equation?

The pOH of a solution is 6 point 0 Which statement is correct? Use pOH is equal to negative log times open bracket OH raised to the negative power close bracket and pH plus pOH is equal to 14

Consider this reaction. 2 SO sub 2 g plus cap o sub 2 times g rightarrow 2 SO sub 3 g What volume of oxygen gas, in milliliters, is required to react with 0 point 6 4 0 g of SO sub 2 gas at STP?

During photosynthesis, sunlight shining on a plant is absorbed. Through several chemical reactions, the plant produces sugar, a high-energy compound, from simpler substances. What energy transformation occurs during this process?

Consider this total ionic equation. 2⁢H^++CrO42−+Ba^2++2⁢OH^−→Ba^2++CrO42−+2⁢H_2O What are the spectator ions in this equation?

How does heat differ from temperature?

A doctor orders a blood sample from a child to test for traces of lead in the blood. Which of these concentration units would best meet this need?

Which task most likely involves a calculation that uses moles?

Which would most likely be the pH of a highly-corrosive acid?

Consider the chemical reaction in equilibrium. cap h sub 2 plus cap i sub 2 plus heat if and only if 2 HI What will happen to the chemical equilibrium if the temperature of the system is increased?

Which best describes the definition of Lewis acids and bases?

According to the collision theory, which is required for a high number of effective collisions?

Consider this system at equilibrium. CaCO sub 3 times s if and only if Ca raised to the 2 plus power times A q plus CO sub 3 raised to the 2 minus power A q The addition of which compound will cause a shift in equilibrium because of a common ion effect?

Consider the rate law below. cap r is equal to k cap l squared XY What is the overall order of the reactants in this reaction?

Consider a balloon that has a volume cap v It contains n moles of gas, it has an internal pressure of cap p , and its temperature is cap t If the balloon is heated to a temperature of 15 point 5 cap t while it is placed under a high pressure of 15 point 5 cap p , how does the volume of the balloon change?

Which value is most likely to be the pH of a salt solution that is formed by the reaction of a strong acid and a weak base?

The balanced equation shows the formation of sulfur dioxide. cap s plus cap o sub 2 rightarrow SO sub 2 How many moles of sulfur are needed to produce 15 point 0 mol of sulfur dioxide?

What is taking place in a reaction as the curve on a reaction pathway graph goes up?

Which equation represents the total ionic equation for the reaction of HNO sub 3 and NaOH ?

Which statement explains why an increase in molality increases the boiling point of a solution?

The decomposition of hydrogen iodide and its rate law are shown. The concentration of HI is 0 point 0 4 5 cap m 2 HI g rightarrow cap h sub 2 of g plus cap i sub 2 times g cap r is equal to k times HI squared At a given temperature, the rate constant is 1 point 6 times 10 to the negative 3 power cap m inverse s inverse What is the rate at this temperature for the given concentrations?

NaCl has a triangle cap h sub fus is equal to 30 point 2 kJ over mol and a triangle cap h sub vap is equal to 171 kJ over mol What mass of NaCl releases 452 kJ of heat as it changes into a liquid? Use q is equal to n triangle cap h

What is the volume of 0 point 2 0 0 mol of an ideal gas at 200 point kPa and 400 point cap k ? Use cap p cap v is equal to n cap r cap t and cap r is equal to 8 point 3 1 4 the fraction with numerator cap l times kPa and denominator mol times cap k

Consider the reaction. 2 cap c sub 6 cap h sub 14 plus 19 cap o sub 2 rightarrow 12 CO sub 2 plus 14 cap h sub 2 cap o How many moles of hexane open paren cap c sub 6 cap h sub 14 close paren must burn to form 18 point 4 mol of carbon dioxide?

Which is the formula mass of open paren NH sub 4 close paren sub 2 SO sub 4 ?

A gas in a rigid container at 25 times degree C has a pressure of 0 point 9 6 atm. A change in temperature causes the pressure to increase to 1 point 2 5 atm. What is the new temperature of the gas? Use the fraction with numerator cap p sub 1 and denominator cap t sub 1 is equal to the fraction with numerator cap p sub 2 and denominator cap t sub 2

Which represents the ionization of a strong electrolyte?

Water is dissolved into n - butanol (a polar liquid). Which is the second step at the molecular level as water dissolves into n - butanol?

What happens to energy when Sally kicks a soccer ball?

Which of the these shows a Bronsted-Lowry acid reacting?

Nitrogen reacts with hydrogen to produce ammonia gas according to this equation. cap n sub 2 times g plus 3 cap h sub 2 g rightarrow 2 NH sub 3 g How many moles of nitrogen would react with excess hydrogen to produce 520 milliliters of ammonia?

What is the mass of ammonium nitrate in 250 milliliters of a 75 percent by mass solution open paren density is equal to 1 point 7 2 5 g over mL close paren ? Use mass percent is equal to mass of solute over mass of solution times 100

From first to last, which lists the order in which these samples will reach 90 point 0 times degree C ?

The volume of a fixed amount of gas is doubled, and the absolute temperature is doubled. According to the ideal gas law, how has the pressure of the gas changed?

Which explanation correctly describes the phase change in the graph?

Which is an example of ionization?

What is the equilibrium constant for the given reaction?

The molar mass of NaOH is 40 point 0 0 g/mol If 5 point 2 0 g NaOH are dissolved in 0 point 5 0 0 liters of solution, what is the molarity of the solution? Use molarity is equal to moles of solute over liters of solution

What is the solubility of Na sub 2 HAsO sub 4 at 60 times degree C ?

Which is the formula mass of Na sub 2 SO sub 4 ?

Which law is based on the graph that is shown below?

An experimental procedure requires 10 ml of acid to be dissolved into a beaker of water. An additional 5 ml of acid is added to the solution. Which statement best describes the new solution?

How many grams of NaCl will be needed to form 600 milliliters of a saturated solution at 100 times degree C ?

Which statement best describes what makes a base weak?

Which statement best explains the event?

The chemical equation for the combustion of acetylene open paren cap c sub 2 cap h sub 2 close paren is given. 2 cap c sub 2 cap h sub 2 g plus 5 cap o sub 2 g rightarrow 4 CO sub 2 g plus 2 cap h sub 2 cap o g What volume of oxygen at STP is required for the complete combustion of 100 point 5 0 milliliters of cap c sub 2 cap h sub 2 ?

What does this piece of evidence best support?

Consider the combustion reaction, 2 cap c sub 4 cap h sub 2 g plus 5 cap o sub 2 g rightarrow 4 CO sub 2 g plus 2 cap h sub 2 cap o g where cap c sub 2 cap h sub 2 , Δ⁢H_f=227.4kJ/mol , CO sub 2 , Δ⁢H_f=−393.5kJ/mol , and cap h sub 2 cap o , Δ⁢H_f=−241.82kJ/mol What is the enthalpy of the reaction? Use Δ⁢H_rxn=∑(Δ⁢H_f_1p⁢r⁢o⁢d⁢u⁢c⁢t⁢s)−∑(Δ⁢H_f_1r⁢e⁢a⁢c⁢tan⁡t⁢s)

Which of these is the strongest acid?

In an experiment, a student wants to increase the rate of a reaction that involves gases. Which change to the reactants would accomplish this?

According to the enthalpy diagram, which of these statements is true?

Catalysts are used in the oil industry to increase octane ratings in gasoline. Octane ratings tell how much fuel has to be compressed to promote better fuel ignition in some cars. Which of these catalytic effects would be most beneficial for the oil industry?

Molecules that have longer arrows are moving faster. Which statement describes what is happening in this system?

Which statement best describes the diagram?

Which of these statements is true?