Chemistry Exam IV
A balanced chemical equation allows one to determine the... A mole ratio of any two substance ps in the reactant B energy relaesed in the reaction C electron configuration of all elements reaction D mechanism involved in the reaction
A
How is Celsius temperature converted to kelvins? A by adding 273.15 B by subtracting 273.15 C by dividing by 273.15 D by multiplying by 273.15
A
Hydroxides of group 1 metals... A are all strong bases B are all weak bases C are all acids D might be either strong or weak bases
A
If one knows he mass and molar mass of reactant A and the molar mass of product D in a chemical reaction, one can determine the massif product D produced by using the.... A mole ratio of D to A from the chemical equation B group numbers of the elements of A and D in the periodic table C estimating bond energies involved in the reaction D electron configurations of the atoms in A and D
A
In the chemical equation wA+xB→yC+zD, if one knows the mass of A and the load masses of A,B,C, and D one can determine... A the mass of any of the reactants or products B the mass of B only C the total mass of C and D only D the total mass of A and B only
A
In the reaction 2H₂+O₂→2H₂O, what is the mole ratio of oxygen to water? A 1:2 B 2:1 C 8:1 D 1:4
A
Standard temperature and pressure for a gas is... A 0 C and 1 atm B 0 K and 1 atm C 0 C and 1 Pa D 0 K and 1 Pa
A
Strong acids are.... A strong electrolytes B weak electrolytes C noneletrolyzed D nonionized
A
Strong bases are... A strong electrolytes B weak electrolytes C nonelectrolytes D also strong acids
A
The enthaply of formation of a compound is -612 kJ/mol, and the products of its combustion have a total enthaply of formation of -671 kJ. What is the enthaply of combustion of this compound? A -59 kJ/mol B -40 kJ/mol C +40 kJ/mol D +59 kJ/mol
A
The greater the kinetic energy of the particles in a sample of matter,.... A the higher the temperature is. B the lower the temperature is. C the more heat the sample will absorb. D the leas heat flows away from the sample.
A
The study of all energy changes is called... A thermodynamics B enthaply C entropy D temperature
A
What is the standard thermodynamics temperature? A 25 C B 25 K C -24.2 J/mol D -484 J/K•mol
A
Which of the following is a measure of the disorder in a system? A entropy B enthalpy C kinetic energy D temperature
A
Which substance has the lowest density? A H₂O(g) B H₂O(l) C H₂,O(s) D H₂O(aq)
A
Whose definition of acids and bases emphasizes the role of protons? A Brønsted and Lowry B Lewis C Arrhenius D Faraday
A
A water solution whose pH is 10.... A Is always neutral B is always basic C is always acidic D might be neutral, basic or acidic
B
Acids taste... A sweet B sour C bitter D salty
B
Entropy decreases as a result of.... A a decrease in pressure B a decrease in temperature C agitation D an increase in temperature
B
I'm the expression q=ncΔT, what do q and n represent? A heat and number of particles B heat and moles of particles C heat capacity and moles of particles D enthaply and moles of particles
B
In the chemical equation wA+xB→yC+zD, how many correct mole ratios can be obtained that relate only the products? A 1 B 2 C 4 D 6
B
In the reaction H₃PO₄+H₂O=H₃O+H₂PO₄, the ion H₂PO₄ acts as a(n)... A acid B base C spectator species D salt
B
In the reaction N₂+3H₂→2NH₃, what is the mole ratio of nitrogen to ammonia? A 1:1 B 1:2 C 1:3 D 2:3
B
Spontaneous reactions are driven by.... A decreasing enthalpy and decreasing entropy B decreasing enthalpy and increasing entropy C increasing enthalpy and decreasing entropy D increasing enthalpy and increasing entropy
B
The Coefficients in a chemical equation represent the... A masses, in grams, of all reactants and products B relative numbers of moles of reactants and products C number of atoms in each compound in a reaction D number of valence electrons involved in the reaction
B
The enthaply of a reaction for a chemical ha he can be determined by... A multiplying the total enthaplies of the product and reactants B subtracting the total enthalpy of the reactants from that of the products C subtracting the total enthalpy of the products from that of the reactants D adding the total enthalpies of the products and reactants
B
The total enthaply of the products in a reaction is 0 kJ, and the total enthaply of the reactants is 100 kJ. What is ΔH for the reaction? A -1116 kJ B -100 kJ C 0 kJ D +100 kJ
B
What happened to the volume of a gas during compression? A the volume increases B the volume decreases C the volume remains constant D it is impossible to tell because all gases are different
B
What is the SI I it of pressure? A torr B pascal C pound D Newton
B
Which of the following best describes temperature? A heat absorbed or released in a chemical or physical change B a measure of the average kinetic energy of the particles in a sample of matter C heat energy D energy of change
B
n the chemical equation wA+xB→yC+zD, a comparison of the number of moles of A to the number of moles of C would be a.... A mass ratio B mole ratio C electron ratio D energy proportion
B
A water solution whose pH is 4... A Is always neutral B is always basic C is always acidic D might be neutral, basic or acidic
C
According to the kinetic-molecular theory, particles of a gas.... A attract each other but do not collide B repel each other and collide C neither attract not repel each other but collide D neither attract not repel each other but do not collide D
C
Enthalpy is the.... A heat of formation at constant pressure B heat of combustion at constant pressure C energy of a system at constant pressure D change in energy of a system at constant pressure
C
For an exothermic reaction, the products.... A are at the same energy level than the reactants B have no energy C are at a lower energy level than the reactants D are at a higher energy level than the reactants
C
In a calorimeter, the energy content of a substance in calculated from measurement of the temperature change in a known mass of... A iron B air C water D steel
C
The kinetic-molecular theory states that gas particles are very far apart. This idea explains of a gas. A the fluidity B the compressibility C the fluidity and compressibility D neither the fluidity nor the compressibility
C
What is needed to calculate the mass of ammonia has produced from 2.0 L of nitrogen gas in excess hydrogen gas in the reaction below? N₂(g)+3H₂(g)→2NH₃(g) A one molar mass and one mole ratio B one molar masses and two mole ratios C two molar masses, one density, and one mole ratio D two densities, two molar masses, and two mole ratios
C
What is the mole ratio of oxygen oh phosphorus(V) oxide in the reaction P₄(S)+5O₂(g)→P₄O₁₀(s)? A 1:1 B 1:5 C 5:1 D 4:10
C
What is the pH of a neutral solution at 25 C? A 0 B 1 C 7 D 14
C
Which of the following is not a property of gases? A gases are fluids B gases have a low density C gases have a definite volume that does not vary from container to container D gases are compressible
C
A conjugate base in the species that... A remains after a base has given up a proton B is formed by the addition of a proton C is formed by the addition of a proton to a base D remains after an acid acid given up a proton
D
Compounds whose enthalpies of formation are highly negative.. A do not exist B are very unstable C are somewhat stable D are very stable
D
How does a gas expand? A its particles become larger B collisions between particles become elastic C it's temperature rises D it's particles moves father apart
D
How many mole ratios can be correctly obtained from the chemical equation 2NO→N₂+O₂? A 1 B 3 C 4 D 6
D
In the reaction Ca+Cl₂→CaCl₂, what is the mole ratio of chlorine to calcium chloride? A 2:3 B 2:1 C 1:2 D 1:1
D
The Greek letter Δ stands for... A "heat stored in." B "mass of." C "rate of." D "change in."
D
The topics covered by the study of thermodynamics include... A energy changes during heating B energy changes during chemical reactions C color changes during chemical reactions D both A and B
D
Which of the following is a measure of the average kinetic energy of the particles in a smalls of matter? A chemical kinetics B thermochemistry C reaction rate D temperate
D