3Covalent bonds mainly occur between — A two nonmetallic elements B two metallic elements C one metallic element and one nonmetallic element D one metalloid and one metallic element
A two nonmetallic elements
4 A compound has a mass of 2.66632 x 10^2 g/mol. The number of significant figures in this mass is — F 2 G 4 H 5 J 6
H 5
26 A student hypothesizes that bromine (Br) has different chemical properties from krypton (Kr). The periodic table supports this hypothesis by indicating that — F bromine is a metal while krypton is a nonmetal G one mole of bromine is heavier than one mole of krypton H bromine and krypton are members of the same family J bromine and krypton have different numbers of valence electrons
J bromine and krypton have different numbers of valence electrons
6 The correct formula for dinitrogen pentoxide is — F N2O5 G N5O H NO5 J N2O
F N2O5
If the pH of a solution is 4, what is the pOH? F 0 G 6 H 7 J 10
J 10
If pressure is increased in an equilibrium reaction, which direction would the equilibrium shift towards?
Towards the side with less moles of gas
14 If a sample has a mass of 1.25 x 10^2 g and a volume of 51 mL, what is its density? F 0.00025 g/mL G 0.0125 g/mL H 2.5 g/mL J 250 g/mL
H 2.5 g/mL
7 When ionic compounds are named, the name of a monatomic anion will end in which of the following suffixes? A -ic B -ite C -ate D -ide
D -ide
24 What is the volume occupied by 51.0 g of ammonia (NH3) gas at STP? F 0.439 L G 22.8 L H 67.2 L J 91.9 L
H 67.2 L
34 Which is the best use for a fume hood? F Storing glassware G Removing toxic vapors H Covering volatile compounds J Mixing chemicals that release O2
G Removing toxic vapors
17 A chemist is examining an unidentified element sample with oxidation states of +2, +3, and +6. The element has a shielding effect similar to that of potassium (K). Which statement about the unidentified element is most likely true? A It has the same number of neutrons as potassium. B It is a transition metal from the same period as potassium. C It is one of the heaviest elements in potassium’s group. D It is a mix of three unstable isotopes of potassium.
B It is a transition metal from the same period as potassium.
9 What is the name of the compound with the formula PCl5? A Phosphorus(I) chloride B Phosphorus(V) chlorine C Phosphorus pentachlorate D Phosphorus pentachloride
D Phosphorus pentachloride
39 CH4 + 2O2 --> CO2 + 2H2O If 1.0 mole of methane reacts with oxygen to produce carbon dioxide and water, what mass of water is produced? A 16 grams B 18 grams C 36 grams D 44 grams
C 36 grams
Cl2 + 2KBr --> Br2 + 2KCl
In this equation, if more Cl2 is added, which way would this equilibrium shift?
To the right
10 How many electrons does the iron ion have when it forms the ionic compound FeCl3? F 20 G 23 H 26 J 29
G 23
Fe2O3 + CO --> Fe + CO2 What are the coefficients of the correctly balanced equation? A 1, 3, 2, 3 B 0, 2, 2, 3 C 1, 2, 2, 2 D 2, 6, 4, 3
A 1,3,2,3
2NH3 (g) --> N2 (g) + 3H2 (g) The reaction for the decomposition of ammonia (NH3) can be written as shown. If a student starts with 21.7 g NH3 of how many grams of hydrogen (H2) gas will be produced by the reaction? F 1.28 g G 2.55 g H 3.85 g J 32.5 g
H 3.85 g