General Chemistry
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Persimmon wood is extremely hard, dense, and wear-resistant. It is used for making musical instruments, tool handles, flooring, and furniture. A sphere of persimmon wood has a diameter of 8.32 cm and a mass of 234 g.
(a) Calculate the density of the persimmon sphere.
(b) Determine whether the sphere would float in water.
(c) Determine whether the sphere will float in petroleum ether (density = 0.653 g/mL).
Invar is an iron-nickel alloy. The composition of invar is 64.0% iron (d = 7.86 g/cm3) and 36.0% nickel (d = 8.90 g/cm3) by mass. Calculate the mass of an invar cylinder in grams that is 1.95 in. in length and 0.675 in. in diameter. Assume that its density changes linearly with composition.
Calculate the density (in g/cm3) of a rectangular tungsten bar weighing 415.5 g with the following measurements: height = 0.800 cm, width = 2.30 cm, and length = 11.7 cm.
What is the volume (in L) of a rectangular block if the block measures 8.50 × 10.0 × 13.5 centimeters?
A sheet of styrofoam (d = 0.12 g/cm3) measuring 2.50 cm × 6.00 cm × 2.00 cm is placed on top of a large basin filled with water. On the center of the styrofoam sheet, a cube of copper (d = 8.96 g/cm3) with an edge of 1.00 cm is also placed. Does the styrofoam-copper combination float or sink? Assume the density of water is 1.00 g/cm3.
A zinc slab weighing 23.50 g was shaped into a square sheet with an edge length of 21.5 cm. If the density of zinc is 7.13 g/cm3, determine the thickness of the sheet (in cm).
Three identical spheres are made up of iron, palladium, and titanium with the following densities 7.87 g/cm3, 11.9 g/cm3, and 4.51 g/cm3, respectively. Arrange the spheres in order of increasing mass.
The atom oxygen-16 has 8 protons and 8 neutrons. Its nucleus has a radius of around 3.02 fm while its atomic radius is around 48 pm. What is the volume of the nucleus? What is the volume of the atom?
The atom iron-56 has 26 protons and 30 neutrons. Its nucleus has a radius of around 4.6 fm while its atomic radius is around 156 pm. Calculate the percentage of the volume of the iron atom that is occupied by the nucleus.
Calculate the radius of a molybdenum atom in angstroms using its volume (9.4 x 10-23 cm3) and the formula for the volume of a sphere
A piece of a silver cube has an edge length of 6.50 cm. Calculate the mass of the cube if the density of silver is 10.49 g/cm3.
A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed structure, with fused rings of five to seven atoms.
Buckminsterfullerene is a type of fullerene that has a density of 1.65 g/cm³. The diameter of one molecule 1.1 nm. Calculate the mass of one molecule of buckminsterfullerene.
A concentration of 100 mg H2S per kilogram of air can already cause various respiratory symptoms. What is the mass of H2S present in a 4.0 × 5.5 × 3.5 m room that is contaminated with that concentration of H2S? Assume that the density of air is 0.001225 g/cm3.
The American Silver Eagle is the official silver bullion coin of the United States. It has a diameter of 40.6 mm and a thickness of 2.98 mm. Silver has a density is 10.49 g/cm3 and is valued at $ 365.90/lb.
Assuming that the coin has a uniform thickness and is made of pure silver, calculate the value of the coin.
Gold wire is used in computer chips to bond as it enables a smooth and uninterrupted flow of electricity. Consider producing gold wire with a 0.01 mm diameter from a gold bar that weighs 12.4 kg. Calculate the length in meters of the wire that would be produced given that the density of gold is 19.3 g/cm3. Assume that the wire is in the shape of a cylinder (V = πr2h, where r = radius, h = height).
Determine the density of a neutron in g/cm3 if it has a radius of approximately 0.8 fm and a mass of 1.67 × 10–27 kg.
Find the radius of a nickel sphere (in mm) with a mass of 110 g.
Calculate the density of brass (in g/cm3) if a brass cylinder has a length of 2.32 cm, a radius of 1.02 cm, and a mass of 65.49 g.
Ethanol is an alternative used in thermometers. Given an ethanol thermometer with 2.540 g of ethanol and a capillary with a diameter of 0.170 mm. Determine the height ethanol rises in the capillary when the temperature rises from 10.0 °C to 20.0 °C? At 10.0 °C density of ethanol is 0.7978 g/cm3 and at 20.0 °C density is 0.7892 g/cm3.
Determine the number of 1-cm squares required to construct a square that is 1.5 m on each side.
A copper (d = 8.96 g/cm3) cube contains 1.58 × 1024 copper atoms. Calculate the edge length (in cm) of the cube.
Engineers are creating rolls of silver foil with a width of 430 mm and thickness of 0.012 mm. Using 1.00 kg of silver, determine the maximum length (in m) of silver foil that can be molded.
Calculate the radius of a tin metal sphere (d=7.31 g/cm3) that contains 9.31x1022 tin atoms. Recall the formula for the volume of a sphere is 4/3 π r3
A non-reactive and non-dissolvable material only floats on the surface of water if it has a density of less than that of water (1.0 g/mL). Determine if a spherical ball with a 0.65 cm radius and 3.7 g weight will float or sink in water. (Note: Volume of a sphere = 4/3πr3.)
Thin cylinders are cut from a large cylinder. The density of the large cylinder is 0.98 g/cm3. It is 350 mm in diameter and 1 m in length. How many thin cylinders can be cut from a large cylinder if each thin cylinder is 0.65 mm thick and 350 mm in diameter? What is the mass of each thin cylinder?
Calculate the grams of gold (d = 19.3 g/cm3) needed to plate a 4.5 in x 3.8 in. surface by 0.0030 in. thick gold.
In scientific notation, a number is expressed as a product of a coefficient and a power of 10. A stone shaped like a sphere has a radius of 2.01×102 cm. Calculate the volume of the stone in cm3. If it has a mass of 1.5×107 g, what is the density (g/cm3) of the stone?
The diameter of a spherical ball of copper is 3.95 cm. If the density of copper is 8.96 g/cm3, determine the mass of the sphere. Use V = (4/3)πr3 to calculate the volume of a sphere, where r is the radius.
A neutron has a mass of 1.0087 amu. If the diameter of a neutron is 1.7000×10−15 m, determine its density in g/cm3.
Copper can be acquired from chalcopyrite, which is 34.63% copper by mass. An ore deposit contains 45.61% chalcopyrite by mass. What mass of ore is needed to create a copper sphere with a radius of 3.0 cm. Assume the extraction process is 96.21% efficient in extracting copper.
Imagine a hypothetical star called a proton star, composed of protons. Assuming that a proton star has the same density as a proton, calculate the mass of a proton star piece with a radius of 1.0 μm. The mass and radius of a proton is 1.67 × 10–27 kg and 0.877 fm, respectively.
During a heist, thieves plan to replace a cylinder of titanium placed in a weight-sensitive pedestal with a cylinder of iron. The cylinder of titanium has a height of 20 cm and a radius of 5 cm. What is the required volume of the iron cylinder to prevent setting off the alarm? The density of titanium is 4.51 g/cm3 and the density of iron is 7.87 g/cm3.