Scientific Investigation
Which of these would be best to measure 12.6 mL of liquid ethanol?
A 25 mL beaker B 25 mL volumetric flask
C 25 mL Erlenmeyer flask D 25 mL graduated cylinder
D 25 mL graduated cylinder
An example of a chemical property is —
F mass of a substance per unit volume
G ability to dissolve in solution
H point where solid becomes liquid
J tendency to undergo oxidation
J tendency to undergo oxidation
Covalent 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
When 1 g of sodium chloride (NaCl) is placed in 100 g of water, a solution results. Once the solution is prepared, water is now considered what part of the solution?
F Solid G Liquid H Solute J Solvent
J Solvent
A saturated solution is one which-
A. contains more solute than the standard amount
B. contains less solute than the standard amount
C. contains the standard amount of solute
C. Contains the standard amount of solute
Which of these are not required to ensure that stock solutions are free of contamination?
A. Store all solutions in a brown bottle
B. Never return excess chemicals to stock bottles
C. Replace tops on reagent bottles after use.
A. Store all solutions in a brown bottle.
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
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
Which of the following is a chemical change?
F Salt is dissolved in water. G Water is boiled on a stove.
H Gasoline combusts in an engine. J Copper metal is stretched into a long wire.
H Gasoline combusts in an engine.
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
If substance X is a liquid, substance Y is a gas, and substance Z is a solid, and all are at the same temperature and pressure, then the order of increasing strength of their intermolecular forces would be — A X < Y < Z B Y < X < Z C Z < Y < X D Y < Z < X
B Y< X <Z
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
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.
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
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
Which of these best describes the basis on which new scientific ideas are accepted or rejected?
A Popular support B Historical support C Compelling evidence D Moral and ethical beliefs
C Compelling evidence
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
The specific heat of aluminum is 0.900 J/g*C. How much heat is required to raise the temperature of a 30.0 g block of aluminum from 25.0 C to 75.0 C? F 0.540 J G 1.50 J H 1350 J J 1670 J
H 1350 J