Chemistry Test - Chapter 9
To balance a chemical equation, it may be necessary to adjust the a. coefficients b. subscripts c. formulas of products d. number of products
a. coefficients
If one knows the mass and molar mass of reactant A and the molar mass of product D in a chemical reaction, one can determine the mass of product S 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. estimated bond of energies involved in the reaction d. electron configurations of the atoms in A and D
a. mole ratio of D to A from the chemical equation
A balanced chemical equation allows one to determine the a. mole ratio of any two substances in the reaction b. energy released in the reaction c. electron configuration of all elements in the reaction d. mechanism involved in the reaction
a. mole ratio of any two substances in the reaction
In most chemical reactions the amount of product obtained is a. equal to the theoretical yield b. less than the theoretical yield c. more than the theoretical yield d. more than the percentage yield
b. less than the theoretical yield
A chemical reaction involving substances A and B stops when B is completely used. B is the a. excess reactant b. limiting reactant c. primary reactant d. primary product
b. limiting reactant
In the chemical reaction represented by the equation wA + xB → yC + zD, a comparison of the number of moles of A to the number moles of C would be a(n) a. mass ratio b. mole ratio c. electron ratio d. energy proportion
b. mole ratio
What is the mole ratio of the actual yield to the theoretical yield, multiplied by 100% a. mole ratio b. percentage yield c. Avogadro yield d. excess yield
b. percentage yield
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. relative numbers of moles of reactants and products
A chemical equation is balanced when the a. coefficients of the reactants equal the coefficients of the products b. same number of each kind of atom appears in the reactants and in the products c. products and reactants are the same chemicals d. subscripts of the reactants equal the subscripts of the products
b. same number of each kind of atom appears in the reactants and in the products
If one knows the mole ratio of a reactant and product in a chemical reaction, one can a. estimate the energy released in the reaction b. calculate the speed of the reaction c. calculate the mass of the product produced from a known mass of reactant d. decide whether the reaction is reversible
c. calculate the mass of the product produced from a known mass of reactant
In the reaction represented by this equation 2Al₂O₃ → 4Al + 3O₂, what is the mole ratio of aluminum to oxygen? a. 10:6 b. 3:4 c. 2:3 d. 4:3
d. 4:3
What is the maximum possible amount of product obtained in a chemical reaction? a. theoretical yield b. percentage yield c. mole ratio d. actual yield
d. actual yield
What is the measured amount of a product obtained from a chemical reaction? a. mole ratio b. percentage yield c. theoretical yield d. actual yield
d. actual yield
Which reactant controls the amount of product formed in a chemical reaction? a. excess reactant b. mole ratio c. composition reactant d. limiting reactant
d. limiting reactant
Which branch of chemistry deals with the mass relationships of elements in compounds and the mass relationships among reactants and products in chemical reactions? a. qualitative analysis b. entropy c. chemical kinetics d. stoichiometry
d. stoichiometry
