The volume of a regular cylinder is V =πr²h. Using the value 3.1416 for the constant π, the volume (cm³) of a cylinder of radius 2.34 cm and height 19.91 cm expressed to the correct number of significant figures is __________.
342
Iron has a density of 7.9 g/cm³. What is the mass of a cube of iron with the length of one side equal to 55.0 mm?
1.3 x 10³ g
How many significant figures should be retained in the result of the following calculation?
12.00000 x 0.9893 + 13.00335 x 0.0107
4
Which one of the following is often easily separated into its components by simple techniques such as filtering or decanting?
heterogeneous mixture
Which calculation clearly shows a conversion between temperatures in degrees Celsius, t(°C), and temperature in Kelvins, T(K)?
T(K) = t(°C) + 273.15
An object will sink in a liquid if the density of the object is greater than that of the liquid. The mass of a sphere is 9.83 g. If the volume of this sphere is less than __________ cm³, then the sphere will sink in liquid mercury (density = 13.6 g/cm³).
0.723
The density of lead is 11.4 g/cm³. The mass of a lead ball with a radius of 0.50 mm is __________ g. (π = 3.1416; Vsphere = 4πr³/3)
6.0 x 10⁻³
The estimated costs for remodelling the interior of an apartment are: three 1-gallon cans of paint at $13.22 each , two paint brushes at $9.53 each , and $135 for a helper. The total estimated cost with the appropriate significant figures is $__________.
194
There should be __________ significant figures in the answer to the following computation.
(10.07 + 7.395) / 2.5
2
One edge of a cube is measured and found to be 13 cm. The volume of the cube in m³ is __________.
2.2 x 10⁻³
If matter is uniform throughout and cannot be separated into other substances by physical processes, but can be decomposed into other substances by chemical processes, it is called a (an)
__________.
compound
Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?
Ca, Sr
Aluminum reacts with a certain nonmetallic element to form a compound with the general formula AlX. Element X is a diatomic gas at room temperature. Element X must be __________.
nitrogen
Aluminum reacts with a certain nonmetallic element to form a compound with the general formula Al₂X₃. Element X must be from Group __________ of the Periodic Table of Elements.
6A
There are __________ electrons, __________ protons, and __________ neutrons in an atom of ¹³²Xe₅₄
54, 54, 78
The average atomic weight of copper, which has two naturally occurring isotopes, is 63.5. One of the isotopes has an atomic weight of 62.9 amu and constitutes 69.1% of the copper isotopes. The other isotope has an abundance of 30.9%. The atomic weight (amu) of the second isotope is __________ amu.
64.8
Of the three types of radioactivity characterized by Rutherford, which is/are electrically charged?
A-rays and B-rays
Pentacarbonyliron (Fe(CO)₅) reacts with phosphorous trifluoride (PF₃) and hydrogen, releasing carbon monoxide:
Fe(CO)₅ + PF₃ + H₂ → Fe(CO)₂(PF₃)₂(H)₂ + CO (not balanced)
The reaction of 5.0 mol of Fe(CO)₅, 8.0 mol of PF₃ and 6.0 mol of H₂ will release __________ mol of CO.
12
When the following equation is balanced, the coefficient of H₂ is __________.
CO (g) + H₂ (g) → H₂O (g) + CH₄ (g)
3
Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO₃ are produced by the reaction of 5.0 grams of O₂ with 6.0 grams of S. What is the % yield of SO₃
in this experiment?
S (s) + O₂ (g) → SO3 (g) (not balanced)
95
What is the maximum amount in grams of SO₃ that can be produced by the reaction of 1.0 g of S with 1.0 g of O₂ via the equation below?
S (s) + O₂ (g) → SO₃ (g) (not balanced)
1.7
When the following equation is balanced, the coefficient of nitric acid is __________.
N₂O₅ (g) + H₂O (l) → HNO₃ (aq)
2
When the following equation is balanced, the coefficient of HCl is __________.
CaCO₃ (s) + HCl (aq) → CaCl₂ (aq) + CO₂ (g) + H₂O (l)
2
When the following equation is balanced, the coefficient of C₃H₈O₃ is __________.
C₃H₈O₃ (g) + O₂ (g) → CO₂ (g) + H₂O (g)
2
Lithium and nitrogen react in a combination reaction to produce lithium nitride:
6Li (s) + N₂ (g) → 2Li₃N (s)
In a particular experiment, 3.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.
5.85
Which one of the following substances is the product of this combination reaction?
Al (s) + I₂ (s) → __________
AlI3
Lithium and nitrogen react in a combination reaction to produce lithium nitride:
6Li (s) + N₂ (g) → 2Li₃N (s)
How many moles of lithium are needed to produce 0.60 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?
1.8
Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:
PbCO₃ (s) → PbO (s) + CO₂ (g)
How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?
2.09
When the following equation is balanced, the coefficient of sulfur dioxide is __________.
PbS (s) + O₂ (g) → PbO (s) + SO₂ (g)
2