Trace amounts of sulfur (S) in coal are burned in the presence of diatomic oxygen $\left(O_{2}\right)$ to form sulfur dioxide $\left(S O_{2}\right).$ Determine the minimum mass of oxygen required in the reactants and the mass of sulfur dioxide in the products when 1 kg of sulfur is burned.

Cardiologists at Athens Medical School in Greece wanted to test whether chocolate affected blood flow in the blood vessels. The researchers recruited 17 healthy young volunteers, who were each given a 3.5-ounce bar of dark chocolate, either bittersweet or fake chocolate. On another day, the volunteers received the other treatment. The order in which subjects received the bittersweet and fake chocolate was determined at random. The subjects had no chocolate outside the study, and investigators didn't know whether a subject had eaten the real or the fake chocolate. An ultrasound was taken of each volunteer's upper arm to see the functioning of the cells in the walls of the main artery. The researchers found that blood vessel function was improved when the subjects ate bittersweet chocolate, and that there were no such changes when they ate the placebo (fake chocolate). Why is it important to randomly assign the order of the treatments for the subjects?

Find an equation for the conic section with the given properties. The parabola with vertex V(5, 5) and directrix the y-axis

Find parametric equations for the given curve. y = cos x, translated so that a maximum occurs at (3, 5)

What does the dew-point temperature of the product gases represent? How is it determined?

Is the air-fuel ratio expressed on a mole basis identical to the air-fuel ratio expressed on a mass basis?

What is the air-fuel ratio? How is it related to the fuel-air ratio?

Is the number of atoms of each element conserved during a chemical reaction? How about the total number of moles?

How does the presence of moisture in air affect the outcome of a combustion process?

How does the presence of $\mathrm{N}_{2}$ in air affect the outcome of a combustion process?

Graph each direct variation equation. y = 2x

Find the exact value of the logarithm without using a calculator. If this is not possible, state the reason. $\log _{4} 16^{3.4}$

What are the approximate chemical compositions of gasoline, diesel fuel, and natural gas?

Solve the equation in the interval

$$[ 0,2 \pi )$$

. cos x sin x - sin x = 0