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 chromatographic procedure separates 4.0 mg of unknown mixture on a column with a length of 40 cm and a diameter of 0.85 cm.

(a) What size column would you use to separate 100 mg of the same mixture?

(b) If the flow is 0.22 mL/min on the small column, what volume flow rate should be used on the large column?

(c) The mobile phase occupies 35% of the column volume. Calculate the linear velocity for the small column and the large column

The cycle in the given figure represents the operation of a gasoline internal combustion engine. Assume the gasoline air intake mixture is an ideal gas with y=1.30. What are the ratios of What is the engine efficiency?

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.

When air is inhaled, it enters the alveoli of the lungs, and varying amounts of the component gases exchange with dissolved gases in the blood. The resulting alveolar gas mixture is quite different from the atmospheric mixture. The following table presents selected data on the composition and partial pressure of four gases in the atmosphere and in the alveoli:

$$\begin{array}{|c|c|c|c|c|} \hline \text { Gas } & \text { Mole \% } & \begin{array}{l} \text { Partial } \\ \text { Pressure (torr) } \end{array} & \text { Mole \% } & \begin{array}{l} \text { Partial } \\ \text { Pressure (torr) } \end{array} \\ \hline \mathrm{N}_2 & 78.6 & - & - & 569 \\ \hline \mathrm{O}_2 & 20.9 & - & - & 104 \\ \hline \mathrm{CO}_2 & 00.04 & - & - & 40 \\ \hline \mathrm{H}_2 \mathrm{O} & 00.46 & - & - & 47 \\ \hline \end{array}$$

If the total pressure of each gas mixture is $1.00 \mathrm{~atm}$, calculate:

(a) The partial pressure (in torr) of each gas in the atmosphere

(b) The mole % of each gas in the alveoli

(c) The number of $\mathrm{O}_2$ molecules in $0.50 \mathrm{~L}$ of alveolar air (volume of an average breath of a person at rest) at $37^{\circ} \mathrm{C}$

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?

Fifty gallons of a $90 \%$ alcohol solution is obtained by mixing a $100 \%$ solution with a $75 \%$ solution. How many gallons of each solution must be used to obtain the desired mixture?

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 being pleased? ________________________

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$_{\mathrm{v}}$?

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?

Each molecular-scale scene below represents a mixture. Describe each one in terms of the number of elements and/or compounds present.

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) $B_{n+1}=0.5 B_n-3$

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 bursting? ________________________

Which of the following statements is the most correct regarding homeostatic imbalance?

a) Positive feedback mechanisms are overwhelmed

b) The internal environment is becoming more stable

c) It is considered the cause of most diseases