One industrial process has an energy consumption of $18.5 \mathrm{kWh} / \mathrm{kg}$ of $\mathrm{Mg}$. How many joules are required per mole $(1 \mathrm{kWh}=1$ kilowatt-hour $=$ $\left.3.6 \times 10^6 \mathrm{~J}\right)$? How does this energy compare with the energy of the following process?

$$\begin{align*} \mathrm{MgCl}_2(\mathrm{~s}) \rightarrow \mathrm{Mg}(\mathrm{s})+\mathrm{Cl}_2(\mathrm{~g}) \end{align*}$$

At what value of x does the quadratic function $f(x)=a x^{2}+b x+c, a \neq 0,$ have a stationary point? Under what conditions is the stationary point a local maximum or a local minimum?

Consider a $15-\mathrm{cm} \times 20-\mathrm{cm}$ printed circuit board $\mathrm{(PCB)}$ that has electronic components on one side. The board is placed in a room at $20^{\circ} \mathrm{C}$. The heat loss from the back surface of the board is negligible. If the circuit board is dissipating $8 \mathrm{~W}$ of power in steady operation, Find the average temperature of the hot surface of the board, assuming the board is $(a)$ vertical; $(b)$ horizontal with hot surface facing up; and $(c)$ horizontal with hot surface facing down. Take the emissivity of the surface of the board to be $0.8$ and assume the surrounding surfaces to be at the same temperature as the air in the room.

The wattage of an appliance indicates the average power consumption in watts $(W)$, where $1 \mathrm{~W}=1 \mathrm{~J} / \mathrm{s}$. What is the difference in the number of $\mathrm{kJ}$ of energy consumed per month between a refrigeration unit that consumes $625 \mathrm{~W}$ and one that consumes $855 \mathrm{~W}$ ? If electricity costs $\$ 0.15$ per $\mathrm{kWh}$, what is the monthly cost difference to operate the two refrigerators? (Assume $30.0$ days in one month and $24.0$ hours per day.)

Find the molar solubility of SrCO3 (Ksp = 5.4 $\times$ 10 - 10) in pure water

Infection that weakens the heart muscle is called _______.

Evaluate each expression. a. 2^4 b. 5^3 c. 8.3^2 d. 1^9 e. 13^1 f. 56.8^0 g. 10^5 h. 100^2 i. 0^12 j. eleven squared k. one and three-tenths cubed l. seven squared times two cubed m. three to the fifth power n. four squared cubed

Water permeability of concrete can be measured by letting water flow across the surface and determining the amount lost (in inches per hour). Suppose that the permeability index x for a randomly selected concrete specimen of a particular type is normally distributed with mean value 1000 and standard deviation 150. a. How likely is it that a single randomly selected specimen will have a permeability index between 850 and 1300? b. If the permeability index is to be determined for each specimen in a random sample of size 10, how likely is it that the sample mean permeability index will be between 950 and 1100? between 850 and 1300?

Complete the square for this expression. Write the resulting expression as a binomial squared.

$$x^2-x+ \square$$

A sample of 250 observations is selected from a normal population for which the population standard deviation is known to be 25. The sample mean is 20. a. Determine the standard error of the mean. b. Explain why we can use formula to determine the 95 percent confidence interval. c. Determine the 95 percent confidence interval for the population mean

Identify each number as real, complex, pure imaginary, or nonreal complex. (More than one of these descriptions will apply.) -4

Write the rational number as a decimal. Then tell whether the decimal is a terminating or a repeating decimal.

$$\frac{4}{12}=$$

Major home appliances purchased in the United States are labeled with bright yellow "Energy Guide" ${ }^{\mathrm{N}}$ tags showing anticipated energy consumption. The tag on a recently purchased washing machine indicated the anticipated energy use would be $940 \mathrm{~kW}$-h per yeas. Calculate the anticipated annual energy use in kilojoules. (See Question 20 for a definition of kilowatt-hour.) At 8 cents/kW-h, how much would it cost per month to operate this machine?

Identify and describe two muscle tissues.