Problem 20a1
The radius of an atom of copper (Cu) is about 140 pm. (a) Express this distance in angstroms 1A 2.
Problem 13a1
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 17.60 g O
Problem 13a4
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 88.00 g O
Problem 14a3
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (a) Calculate the mass of fluorine per gram of iodine in Compound 3.
Problem 98a1
There are two different isotopes of bromine atoms. Under normal conditions, elemental bromine consists of Br2 molecules, and the mass of a Br2 molecule is the sum of the masses of the two atoms in the molecule. The mass spectrum of Br2 consists of three peaks: Mass (u) Relative Size 157.836 0.2569 159.834 0.4999 161.832 0.2431 (a) What is the origin of second (mass of 159.834 amu) peak (of what isotopes does each consist)?
Problem 90c1
"The diameter of a rubidium atom is 495 pm We will consider two different ways of placing the atoms on a surface. In arrangement A, all the atoms are lined up with one another to form a square grid. Arrangement B is called a close-packed arrangement because the atoms sit in the 'depressions' formed by the previous row of atoms:
(c) By what factor has the number of atoms on the surface increased in going to arrangement B from arrangement A?
Problem 90c2
"The diameter of a rubidium atom is 495 pm We will consider two different ways of placing the atoms on a surface. In arrangement A, all the atoms are lined up with one another to form a square grid. Arrangement B is called a close-packed arrangement because the atoms sit in the 'depressions' formed by the previous row of atoms:
(c) If extended to three dimensions, which arrangement would lead to a greater density for Rb metal?"
Problem 81b3
(b) Pentane is the alkane with a chain of five carbon atoms. Determine its empirical formula.
Problem 108a2
Cyclopropane is an interesting hydrocarbon. Instead of having three carbons in a row, the three carbons form a ring, as shown in this perspective drawing (see Figure 2.18 for a prior example of this kind of drawing):
Cyclopropane was at one time used as an anesthetic, but its use was discontinued, in part because it is highly flammable. (a) How does it differ from that of propane?
Problem 81b2
(b) Pentane is the alkane with a chain of five carbon atoms. Determine its molecular formula.
Problem 36
Rubidium has two naturally occurring isotopes, rubidium-85 (atomic mass = 84.9118 amu; abundance = 72.15%) and rubidium-87 (atomic mass = 86.9092 amu; abundance = 27.85%). Calculate the atomic weight of rubidium
Problem 13a2
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 35.20 g O
Problem 13a3
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 70.40 g O
Problem 14a2
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (a) Calculate the mass of fluorine per gram of iodine in Compound 2.
Problem 1a
A charged particle moves between two electrically charged plates, as shown here.
(a) What is the sign of the electrical charge on the particle?
Problem 2a
The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the blue spheres are 295Nv. (a) Assuming that this sample is a statistically representative sample of the element, calculate the percent abundance of each element.
Problem 2b
The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the blue spheres are 295Nv. (b) If the mass of 293Nv is 293.15 u and that of 295Nv is 295.15 u, what is the atomic weight of Nv?
Problem 3a
Four of the boxes in the following periodic table are colored. Which of these are metals and which are nonmetals?
Problem 4a
Does the following drawing represent a neutral atom or an ion?
Problem 5
Which of the following diagrams most likely represents an ionic compound, and which represents a molecular one? Explain your choice.
Problem 7
Five of the boxes in the following periodic table are colored. Predict the charge on the ion associated with each of these elements.
Problem 8
The following diagram represents an ionic compound in which the red spheres represent cations and the blue spheres represent anions. Which of the following formulas is consistent with the drawing? KBr, K2SO4, Ca1NO322, Fe21SO423.
Problem 10a
In the Millikan oil-drop experiment (see Figure 2.5), the tiny oil drops are observed through the viewing lens as rising, stationary, or falling, as shown here. (a) What causes their rate of fall to vary from their rate in the absence of an electric field?
Problem 11a
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. (a) What is the ratio of the mass of O to C?
Problem 11b
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. (b) If a sample of a different compound decomposes into 0.429 g of carbon and 0.571 g of oxygen, what is its ratio of the mass of O to C?
Problem 11c
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. If a sample of a different compound decomposes into 0.429 g of carbon and 0.571 g of oxygen, what is its ratio of the mass of O to C? (c) According to Dalton's atomic theory, what is the empirical formula of the second compound?
Problem 12b
Sodium reacts with oxygen in air to form two compounds: sodium oxide and sodium peroxide. In forming sodium oxide, 23.0 g of sodium combines with 8.0 g of hydrogen. In forming sodium peroxide, 23.0 g of sodium combines with 16.0 g of oxygen. (b) What fundamental law does this experiment demonstrate?
Problem 13b
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (b) How do the numbers in part (a) support Dalton's atomic theory?
Problem 14b
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (b) How do the numbers in part (a) support the atomic theory?
Problem 15
Discovering which of the three subatomic particles proved to be the most difficult—the proton, neutron, or electron? Why?
Ch.2 - Atoms, Molecules, and Ions
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