Which terms identify types of chemical reactions? (1) decomposition and :sublimation (2) decomposition and synthesis (3) deposition and sublimation (4) deposition and synthesis
Which reaction is single replacement? (1) 2H2O2 --> 2H2O + O2 (2) 2H2 + O2 --> 2H2O (3) H2SO4 + Mg --> H2 + MgSO4 (4) HCl + KOH --> KCl + H2O
Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) ==> Al2O3(s) As the aluminum loses 12 moles of electrons, the oxygen (1) gains 4 moles of electrons (2) gains 12 moles of electrons (3) loses 4 moles of electrons (4) loses .12 moles of electrons
Which element has atoms with the strongest attraction for electrons in a chemical bond? (1) chlorine (3) fluorine (2) nitrogen (4) oxygen
When lithium reacts with bromine to form the compound LiBr each lithium atom (1) gains one electron and becomes a negatively charged ion (2) gains three electrons and becomes a negatively charged ion (3) loses one electron and becomes a positively charged ion (4) loses three electrons and becomes a positively charged ion
Given the balanced equation representing a reaction: Al2(SO4)3 +6NaOH ==> 2Al(OH)3 + 3Na2SO4 The mole ratio of NaOH to Al(OH)3 is (1) 1:1 (2) 3:1 (3) 1:3 (4) 3:7
Given the balanced equation representing a reaction: O2 --> O + O What occurs during this reaction? (1) Energy is absorbed as bonds are broken. (2) Energy is absorbed as bonds are formed. (3) Energy is released as bonds are broken. (4) Energy is released as bonds arc formed.
When an excited electron in an atom moves to the ground state, the electron (1) absorbs energy as it moves to a higher energy state (2) absorbs energy as it moves to a lower energy state (3) emits energy as it moves to a higher energy :state (4) emits energy as it moves to a lower energy state
What type of formula represents the simplest whole number ratio of atoms of the elements in a compound? (1) molecular formula (2) condensed formula (3) empirical formula (4) structural formula
Which change results in the formation of different substances? (1) burning of propane (2) melting of NaCl (s) (3) deposition of CO2(g) (4) solidification of water
Which statement describes a reversible reaction at equilibrium? (1) The activation energy of the forward reaction must equal the activation energy of the reverse reaction. (2) The rate of the forward reaction must equal the rate of the reverse reaction. (3) The concentration of the reactants must equal the concentration of the products. (4) The potential energy of the reactants must equal the potential energy of the products.
A sample of a substance has these characteristics: • melting point or 9811 K • hard. brittle solid at room temperature • poor conductor of heat and electricity as a solid • good conductor of electricity as a liquid or in an aqueous solution This sample is classified as (1) a metallic element (2) a radioactive element (3) a molecular compound (4) an ionic compound
Compared to the physical and chemical properties of the compound NO2 the compound N2O has (1) different physical properties and different chemical properties (2) different physical properties and the same chemical properties (3) the same physical properties and different chemical properties (4) the same physical properties and the same chemical properties
The coefficients in a balanced chemical equation represent (l ) the mass ratios of the substances in the reaction (2) the mole ratios of the substances in the reaction (3) the total number of electrons in the reaction (4) the total number of elements in the reaction
