Classify substance Cytosine, a component of DNA, consists of H, C, N, and O atoms bonded in a specific arrangement, as an element, compound, or mixture, and explain your answer.

Forty gallons of a $60 \%$ acid solution is obtained by mixing a $75 \%$ solution with a $50 \%$ solution. How many gallons of each solution must be used to obtain the desired mixture?

A mixture of nuts contains 1 cup of walnuts for every 3 cups of peanuts.

Write a linear equation that represents the relationship between peanuts, x, and walnuts, y.

Classify substance Calcium chloride, used to melt ice on roads, consists of two elements, calcium and chlorine, in a fixed mass ratio as an element, compound, or mixture, and explain your answer.

(a) Find all equilibrium solutions for the equation

$$\frac{d y}{d x}=0.5 y(y-4)(2+y)$$

(b) With a calculator or computer, draw a slope field for this differential equation. Use it to determine whether each equilibrium solution is stable or unstable.

Use these words that end in the suffix -ure to answer the following questions.

mixture pleasure signature fracture

Which word can mean the result of mixing? ________________________

A gas mixture contains $1.5 \times 10^{-5}$ mole $\mathrm{CO}$ and has a total of 1 mole. What is the $\mathrm{CO}$ concentration in ppm$_{\mathrm{v}}$?

Consider the ketones menthone and isomenthone. Propose an explanation for the observation that menthone is converted to a mixture of menthone and isomenthone on treatment with 90% sulfuric acid.

A frame in the shape of the simple scissors truss shown at the right below can be used to support a peaked roof. The weight of the roof compresses some parts of the frame (green), while other parts are in tension (blue). A frame made with $s$ segments joined at $j$ points is stable if $s \geq 2 j-3$. In the truss shown, 9 segments connect 6 points. Verify that the truss is stable. Then find the values of $x$ and $y$.

Determine equilibrium values for the given dynamical systems and state whether these equilibrium values are stable. a) $A_{n+1}=3 A_n-1$ b) $B_{n+1}=0.5 B_n-3$

For each molecule in the indicated problem, estimate the energy difference between the most stable and next best conformation. Calculate the approximate ratio of the two at $300 \mathrm{~K}$.

Which of the following mixture types can be filtered to remove solute?

A) suspensions

B) only colloids

C) only suspensions

D) colloids suspensions and solutions

A mixture containing only Al$_2$O$_3$ (FM 101.96) and Fe$_2$O$_3$ (FM 159.69) weighs 2.019 g. When heated under a stream of H2, Al2O3 is unchanged, but Fe$_2$O$_3$ is converted into metallic Fe plus H$_2$O(g). If the residue weighs 1.774 g, what is the weight percent of Fe$_2$O$_3$ in the original mixture?

If you dilute a can of orange juice that is $75 \mathrm{~mL}$ with enough water to make a total volume of $300 \mathrm{~mL}$, what is the percentage of juice in the mixture?