Chapter 1, Problem 1.27E

Some scientists think there are living things smaller than bacteria (New York Times, January 18, 2000, p. D1). Called nanobes, they are roughly cylindrical and range from 20 to 150 nm long and about 10 nm in diameter. One approach to determining whether nanobes are living is to estimate how many atoms and molecules could make up a nanobe. If the number is too small, then there would not be enough DNA, protein, and other biological molecules to carry out life processes. To test this method, estimate an upper limit for the number of atoms that could be in a nanobe. (Use a small atom, such as hydrogen.) Also estimate how many protein molecules could fit inside a nanobe. Do your estimates rule out the possibility that a nanobe could be living? Explain why or why not.

A 2.0-mer volume of hydrogen gas combined with 1.0 liter of oxygen gas to produce 2.0 liters of water vapor. Does oxygen undergo a chemical or physical change?

On October 21, 1982, the Bureau of the Mint changed the composition of pennies (see Exercise 120). Instead of an alloy of 95% Cu and 5% Zn by mass, a core of 99.2% Zn and 0.8% Cu with a thin shell of copper was adopted. The overall composition of the new penny was 97.6% Zn and 2.4% Cu by mass. Does this account for the difference in mass among die pennies in Exercise 120? Assume the volume of the individual metals that make up each penny can be added together to give the overall volume of the penny, and assume each penny is the same size. (Density of Cu = 8.96 g/cm3; density of Zn = 7.14 g/cm3).

What instrument would you use to (a) measure the length of your bed? (b) measure the amount of acid delivered by a beaker? (c) determine whether you have a fever?

The mass of one atom or molecule of a substance is given in atomic mass units, also called Daltons (abbreviated D or Da). Thus one molecule of water has a mass of 18.015 atomic mass units, or 18.015 Daltons. The atomic mass unit is defined such that one mole of water weighs 18.015 g. Suppose a protein has a mass of 64 192 Daltons (or 64.192 kDa). What would be the mass of one mole of this protein? O A. A protein of 64 192 Da has a molar mass of 3.866 x 1028 g/mol. B. A protein of 64 192 Da has a molar mass of 1.0 g/mol. C. A protein of 64 192 Da has a molar mass of 18.015 g/mol. D. A protein of 64 192 Da has a molar mass of 64.192 g/mol. E. This question can't be answered without knowing the number of atoms in the protein. F. A protein of 64 192 Da has a molar mass of 6.4192 x 10-2 g/mol. G. A protein of 64 192 Da has a molar mass of 3.866 x 1025 g/mol. H. A protein of 64 192 Da has a molar mass of 64 192 g/mol.

II. BOILING POINT ELEVATION: The temperature of a boiling 50 mL of distilled water in an Erlenmeyer flask with a small flame was taken to be 98°C. The bulb of the thermometer must not touch the bottom or sides of the Erlenmeyer flask. In another Erlenmeyer flask, 2.83 grams of urea is dissolved in 10 grams of distilled water. The solution was let to boil gently and its boiling point was recorded to be 101°C. DATA AND RESULTS: (Show all pertinent computations on the space provided if applicable. Answers with no computation will not be considered.) Mass of urea in grams Mass of water in grams Boiling point of distilled water in degrees Celsius Boiling point of urea solution in degrees Celsius Molecular weight of urea in g/mol (experimental) Molecular weight of urea in g/mol (calculated) Percent Error of Molecular weights of urea Change in boiling point SOLUTION/S:

The speed limit on road in Mexico is 90 km/hr. What is this speed equivalent to on moles per hour, if 1.00 = 0.621 mile?

Mr. Auric Goldfinger, criminal mastermind, intends to smuggle several tons of gold across international borders by disguising it as lumps of iron ore. He commands his engineer minions to form the gold into little spheres with a diameter of exactly 8 cm and paint them black. However, his chief engineer points out that customs officials will surely notice the unusual weight of the "iron ore" if the balls are made of solid gold (density 19.3 g/cm"). He suggests forming the gold into hollow balls One of the balls of fake instead (see sketch at right), so that the fake "iron ore" has the same density as real iron ore (5.15 g/cm'). "iron ore," sliced in half. Calculate the required thickness of the walls of each hollow lump of "iron ore." Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

Whilst working in the pharmacy aseptic unit you are asked to prepare 5 litres of a solution containing potassium ions 1 mmol/mL. What weight of potassium chloride is required? (atomic weight of potassium = 39: atomic weight of chlorine = 35.5) Units - g