Seawater containing 3.50 wt% salt passes through a series of 10 evaporators. Roughly equal quantities of water are vaporized in each of the 10 units and then condensed and combined to obtain a product stream of fresh water. The brine leaving each evaporator but the tenth is fed to the next evaporator. The brine leaving the tenth evaporator contains 5.00 wt% salt. a) Draw a flowchart of the process showing the first, fourth, and tenth evaporators. Label all the streams entering and leaving these three evaporators. b) Write in order the set of equations you would solve to determine the fractional yield of fresh water from the process (kg $\mathrm{H}_{2} \mathrm{O}$ recovered/kg $\mathrm{H}_{2} \mathrm{O}$ in process feed) and the weight percent of salt in the solution leaving the fourth evaporator. Each equation you write should contain no more than one previously undetermined variable. In each equation, circle the variable for which you would solve. Do not do the calculations. c) Solve the equations derived in Part (b) for the two specified quantities. d) The problem statement made no mention of the disposition of the 5 wt% effluent from the tenth evaporator. Suggest two possibilities for its disposition and describe any environmental concerns that might need to be considered.

Students collected 600 cans for the canned food drive. That was 80% of their goal. How many more cans do they need to collect to reach their goal?

Solve each equation. $7(b+3)-18(1-b)=103$

Tu profesor(a) te va a dar una lista de diligencias (errands). Algunas las hiciste tú y algunas las hizo tu compañero/a. Las diligencias que ya hicieron tienen esta marca ✔. Pero quedan cuatro diligencias por hacer. Dale mandatos a tu compañero/a, y él/ella responde para confirmar si hay que hacerla o si ya la hizo.

Find the exact values of the six trigonometric functions of the angle $\theta$. $\sin \theta=\frac{7}{10}$

Use the order of operations to simplify each expression. $40+24 \div\left(8-2^{2}\right)-1$

The volume of a microbial culture is observed to increase according to the formula $V\left(\mathrm{cm}^{3}\right)=a e^{b t}$ where t is time in seconds. a) Calculate the expression for $V\left(\mathrm{in}^{3}\right)$ in terms of t(h). b) Since both the exponential function and its argument must be dimensionless, what must be the units of a and b?

One thousand kilograms per hour of a mixture containing equal parts by mass of methanol and water is distilled. Product streams leave the top and the bottom of the distillation column. The flow rate of the bottom stream is measured and found to be 673 kg/h, and the overhead stream is analyzed and found contain 96.0 wt% methanol. a) Draw and label a flowchart of the process and do the degree-of-freedom analysis. b) Calculate the mass and mole fractions of methanol and the molar flow rates of methanol and water in the bottom product stream. c) Suppose the bottom product stream is analyzed and the mole fraction of methanol is found to be significantly higher than the value calculated in Part (b). List as many possible reasons for the discrepancy as you can think of. Include in your list possible violations of assumptions made in Part (b).

Two mercury manometers, one open-end and the other sealed-end, are attached to an air duct. The reading on the open-end manometer is 25 mm and that on the sealed-end manometer is 800 mm. Determine the absolute pressure in the duct, the gauge pressure in the duct, and the atmospheric pressure, all in mm Hg.

The density of a fluid is given by the empirical equation $\rho=70.5 \exp \left(8.27 \times 10^{-7} P\right)$ where $\rho$ is density $\left(\mathrm{lb}_{\mathrm{m}} / \mathrm{ft}^{3}\right)$ and P is pressure $\left(\mathrm{lb}_{\mathrm{f}} / \mathrm{in}^{2}\right)$. a) What are the units of 70:5 and $8.27 \times 10^{-7}$? b) Calculate the density in $\mathrm{g} / \mathrm{cm}^{3}$ for pressure of $9.00 \times 10^{6} \mathrm{N} / \mathrm{m}^{2}$. c) Derive a formula for $\rho\left(\mathrm{g} / \mathrm{cm}^{3}\right)$ as a function of $P\left(\mathrm{N} / \mathrm{m}^{2}\right)$. Check your result using the solution of Part (b).

The Hamiltonian for a certain three-level system is represented by the matrix

$$H=\left(\begin{array}{lll}{a} & {0} & {b} \\ {0} & {c} & {0} \\ {b} & {0} & {a}\end{array}\right)$$

, where a, b, and c are real numbers. (a) If the system starts out in the state

$$|\mathcal{S}(0)\rangle=\left(\begin{array}{l}{0} \\ {1} \\ {0}\end{array}\right)$$

, what is $|\mathcal{S}(t)\rangle ?$ (b) If the system starts out in the state

$$|\mathcal{S}(0)\rangle=\left(\begin{array}{l}{1} \\ {0} \\ {0}\end{array}\right)$$

, what is $|\mathcal{S}(t)\rangle ?$

Complete the sentence in a way that shows you understand the meaning of the italicized vocabulary word. The fetid smell was coming from...

The indicator-dilution method is a technique used to determine flow rates of fluids in channels for which devices like rotameters and orifice meters cannot be used (e.g., rivers, blood vessels, and large-diameter pipelines). A stream of an easily measured substance (the tracer) is injected into the channel at a known rate, and the tracer concentration is measured at a point far enough downstream of the injection point for the tracer to be completely mixed with the flowing fluid. The larger the flow rate of the fluid, the lower the tracer concentration at the measurement point. A gas stream that contains 1.50 mole% $\mathrm{CO}_{2}$ flows through a pipeline. Twenty (20.0) kilograms of $\mathrm{CO}_{2}$ per minute is injected into the line. A sample of the gas is drawn from a point in the line 150 meters downstream of the injection point and found to contain 2.3 mole% $\mathrm{CO}_{2}$. a) Estimate the gas flow rate (kmol/min) upstream of the injection point. b) Eighteen seconds elapse from the instant the additional $\mathrm{CO}_{2}$ is first injected to the time the $\mathrm{CO}_{2}$ concentration at the measurement point begins to rise. Assuming that the tracer travels at the average velocity of the gas in the pipeline (i.e., neglecting diffusion of $\mathrm{CO}_{2}$), estimate the average velocity (m/s). If the molar gas density is $0.123 \mathrm{kmol} / \mathrm{m}^{3}$, what is the pipe diameter/

Two streams flow into a 500-gallon tank. The first stream is 10.0 wt% ethanol and 90.0% hexane (the mixture density, $\rho_{1}$, is $0.68 \mathrm{g} / \mathrm{cm}^{3}$ and the second is 90.0 wt% ethanol, 10.0% hexane $\left(\rho_{2}=0.78 \mathrm{g} / \mathrm{cm}^{3}\right)$. After the tank has been filled, which takes 22 min, an analysis of its contents determines that the mixture is 60.0 wt% ethanol, 40.0% hexane. You wish to estimate the density of the final mixture and the mass and volumetric flow rates of the two feed streams. a) Draw and label a flowchart of the mixing process and do the degree-of-freedom analysis. b)