Chemistry for Engineering Students 2nd. Edition by Larry Brown, Tom Holme | 9781439047910 | 143904791X

General Chemistry

Chemistry for Engineering Students

1 SOLVED PROBLEMS

130 SOLVED PROBLEMS

Question: 7.FP.1

An unidentified solid is dissolved in water to produce a clear, colorless solution, and this solution conducts electricity. A second solution is added, and a precipitate forms. Once the precipitate has settled, the liquid above it does not conduct electricity perceptibly. What does this experiment ...

Verified Answer:

For any substance to conduct electricity, it must ...

Question: 9.8

Use tabulated data to find the heat of combustion of one mole of propane, C3H8, to form gaseous carbon dioxide and liquid water. Strategy We will need values for the heats of formation of the reactants and products to determine the desired heat of combustion. First, we must write a balanced ...

Verified Answer:

{\mathrm C}_{3}{\mathrm H}_{8}({\mathrm g})...

Question: 6.7

Rewrite the electron configuration for sulfur (Example Problem 6.6) using the short-hand notation introduced above. ...

Verified Answer:

Strategy We found the electron configuration in Ex...

Question: 14.F.1

Suppose that you are working for a company that prepares radioisotopes for medical imaging. You receive an order from a researcher requesting 15 mg of ^45Ti for an experiment. The customer’s laboratory is located roughly 1.5 hours from your production source. How would you determine what mass of ...

Verified Answer:

Once we know the half-life, we can determine the r...

Question: 14.6

Calculate the energy released by a nucleus of uranium-235 if it splits into a barium-141 nucleus and a krypton-92 nucleus according to the equation above. Strategy Einstein’s equation (E = mc²) relates the energy released to the difference in mass between the fissile uranium nuclide and the ...

Verified Answer:

The masses of the various particles involved are s...

Question: 14.5

A piece of cloth is discovered in a burial pit in the southwestern United States. A tiny sample of the cloth is burned to CO2, and the ^14C/^12C ratio is 0.250 times the ratio in today’s atmosphere. How old is the cloth? Strategy We have the decay constant, k, for the relevant process from Example ...

Verified Answer:

Recall from Example Problem 14.4

\begin{gat...

Question: 14.4

The half-life of carbon-14, used in radiocarbon dating, is 5730 years. What is the decay constant for carbon-14? Strategy The half-life and the decay constant are alternative ways of characterizing the rate of decay, so knowing one allows us to find the other. The needed relationship is given in ...

Verified Answer:

\begin{gathered}t_{1 / 2}=\frac{0.693}{k} \...

Question: 14.3

Complete the following equations with the correct particles and identify the mode of decay. (a) ^15 8O → ^15 7N + ? (b) ^40 19K → ? + ^0 -1β + ν (c) ^40 19K + ? → ^40 18Ar + ν Strategy As before, we rely on both mass numbers and charges to identify the missing species in the equations. Once each ...

Verified Answer:

Consider each equation in turn. (a)

{ }_8^{...

Question: 14.2

We have seen the nuclear equation for the beta decay involved in radiocarbon dating. Now complete the equations for each of the following β^- decay reactions, using 0^-1β to represent the beta particle. ^234 90Th → ^234 91Pa + ? ^234 91Pa → ? + ^-1 0β + ν Strategy We can use both the mass numbers ...

Verified Answer:

Consider each equation separately, starting with t...

Question: 14.1

Complete the equations for each of the following nuclear decay processes. ^210 84Po → ^206 82Pb + ? ^230 90Th → ? + ^4 2He Strategy Nuclear equations must be balanced with respect to both total mass and charge. As long as only one particle is missing from each equation, we can use these two ...

Verified Answer:

Consider the first reaction. Looking at the two is...

Question: 13.F.1

You are working on the design of a battery and need to have a small button plated with silver (because it has useful conductive properties and is corrosion resistant). You determine that a coating of 1 mm will suffice for the design. What would you have to look up to devise an initial cost estimate ...

Verified Answer:

The first, and probably most important, estimate w...