If two similar basins containing unequal quantities of water are placed in the sunshine on a summer day, the smaller quantity of water will become quite warm in a short period of time, while the larger quantity will become only lukewarm. Both vessels receive the same amount of heat from the sun, but in one case the heat is utilized in heating to a high temperature a small quantity of water, while in the second case the heat is utilized in warming to a lower degree a larger quantity of water. Equal amounts of heat do not necessarily produce equivalent temperatures, and equal temperatures do not necessarily indicate equal amounts of heat. It takes more heat to raise a gallon of water to the boiling point than it does to raise a pint of water to the boiling point, but a thermometer would register the same temperature in the two cases. The temperature of boiling water is 100° C. whether there is a pint of it or a gallon. Temperature is independent of the quantity of matter present; but the amount of heat contained in a substance at any temperature is not independent of quantity, being greater in the larger quantity.
1. Based on the passage above, which of these factors contributes to the fact that a pint of water can be raised to boiling point more quickly than a gallon of water when both are exposed to the same amount of heat?
A. the amount of water in a gallon is more than the amount of water in a pint
B. the pint of water is in a tin pail and the gallon of water is in a plastic jug
C. the pint of water is tinted blue while the gallon of water is not tinted
D. the gallon of water has been filtered
2. What is the temperature of boiling water?
B. 100° C
3. Which of the following statements is untrue?
A. Temperature is independent of the quantity of matter present.
B. The temperature of boiling water is 100°C.
C. Equal amounts of heat do not necessarily produce equivalent temperatures.
D. Temperature is dependent upon the quantity of matter present.
4. Explain what equipment would be needed to perform the experiment described in the passage above. If two similar basins containing unequal quantities of water are placed in the sunshine on a summer day, the smaller quantity of water will become quite warm in a short period of time, while the larger quantity will become only lukewarm.
A. two equal size basins, water, a thermometer
B. a milk jug and tin can, water and ice, ruler
C. one basin, two glasses of water, string
D. two equal size basins, two equal amounts of water, thermometer
5. What would be a suitable hypothesis if the above passage were organized into a science project?
A. If temperature is related to the amount of matter present, then smaller amounts of matter will heat more quickly.
B. If temperature is constant, water will boil at 100°C.
C. The amount of matter in a container can be heated by a natural light source.
D. Temperature is unrelated to the amount of matter.
Ribbons and dresses washed and hung in the sun fade; when washed and hung in the shade, they are not so apt to lose their color. Clothes are laid away in drawers and hung in closets not only for protection against dust, but also against the well-known power of light to weaken color. Many housewives lower the window shades that the wall paper may not lose its brilliancy, that the beautiful hues of velvet, satin, and plush tapestry may not be marred by loss in brilliancy and sheen. Bright carpets and rugs are sometimes bought in preference to more delicately tinted ones, because the purchaser knows that the latter will fade quickly if used in a sunny room, and will soon acquire a dull mellow tone. The bright and gay colors and the dull and somber colors are all affected by the sun, but why one should be affected more than another we do not know. Thousands of brilliant and dainty hues catch our eye in the shop and on the street, but not one of them is absolutely permanent; some may last for years, but there is always more or less fading in time.
Sunlight causes many strange, unexplained effects. If the two substances, chlorine and hydrogen, are mixed in a dark room, nothing remarkable occurs any more than though water and milk were mixed, but if a mixture of these substances is exposed to sunlight, a violent explosion occurs and an entirely new substance is formed, a compound entirely different in character from either of its components. By some power not understood by man, the sun is able to form new substances. In the dark, chlorine and hydrogen are simply chlorine and hydrogen; in the sunlight they combine as if by magic into a totally different substance. By the same unexplained power, the sun frequently does just the opposite work; instead of combining two substances to make one new product, the sun may separate or break down some particular substance into its various elements. For example, if the sun’s rays fall upon silver chloride, a chemical action immediately begins, and as a result we have two separate substances, chlorine and silver. The sunlight separates silver chloride into its constituents, silver and chlorine.
6. What additional component is needed to cause a mixture of chlorine and hydrogen to explode?
D. carbon dioxide
7. What is formed when sunlight reacts with silver chloride?
A. silver and aluminum
B. copper and metal alloy
C. tin and zinc
D. silver and chlorine
8. Which of these statements is untrue based on the passage above?
A. Sunlight can cause chemical reactions to occur.
B. Sunlight is known to fade the color in fabrics over time.
C. When a piece of fabric is dyed, the color is absolutely permanent.
D. Clothing stored in closets and drawers can be protected from the fading.
9. Which of these is not described in the above passage as a power of the sun?
A. fading colors
B. forming new substances
C. separating one substance into two
D. heating water
10. The above passage compares the mixing of hydrogen and chlorine in a dark room to the mixing of:
A. sulfur and oxygen
B. silver and chloride
C. milk and water
D. oil and vinegar
The far-reaching effect which light has upon some inanimate objects, such as photographic films and clothes, leads us to inquire into the relation which exists between light and living things. We know from daily observation that plants must have light in order to thrive and grow. A healthy plant brought into a dark room soon loses its vigor and freshness, and becomes yellow and drooping. Plants do not all agree as to the amount of light they require, for some, like the violet and the arbutus, grow best in moderate light, while others, like the willows, need the strong, full beams of the sun. But nearly all common plants, whatever they are, sicken and die if deprived of sunlight for a long time. This is likewise true in the animal world. During long transportation, animals are sometimes necessarily confined in dark cars, with the result that many deaths occur, even though the car is well aired and ventilated and the food supply good. Light and fresh air put color into pale cheeks, just as light and air transform sickly, yellowish plants into hardy green ones. Plenty of fresh air, light, and pure water are the watchwords against disease.
11. In the above passage, which statement offers proof that plants must have light in order to grow?
A. A healthy plant brought into a dark room soon loses its vigor and freshness, and becomes yellow and drooping.
B. Plants do not all agree as to the amount of light they require.
C. We know from daily observation that plants must have light in order to thrive and grow.
D. But nearly all common plants, whatever they are, sicken and die if deprived of sunlight for a long time.
12. Which statement is untrue based on the information provided in the above passage?
A. All plants require some amount of light to grow and thrive.
B. Plants are incapable of thriving in low light.
C. Overexposure to sunlight can stunt plant growth.
D. Plants and animals can die if deprived of sunlight for too long.
13. What are the three elements that can ward off disease in plants?
A. cool air, humidity, oxygen
B. water, soil, fungicide
C. fresh air, light, pure water
D. sand, humidity, light
14. Which type of light is most effective for growing violets?
A. high light
B. moderate light
C. constant shade
D. no light
15. Based on the information in the passage, a willow placed in an area of low light would most likely:
A. die immediately
B. grow to its full potential
C. not grow to its full potential
D. begin to flower
Oxygen is a colorless, odorless, tasteless gas, slightly heavier than air. One liter of it, measured at a temperature of 0° and under a pressure of one atmosphere, weighs 1.4285 g., while under similar conditions one liter of air weighs 1.2923 g. It is but slightly soluble in water. Oxygen, like other gases, may be liquefied by applying very great pressure to the highly cooled gas. When the pressure is removed the liquid oxygen passes again into the gaseous state, since its boiling point under ordinary atmospheric pressure is -182.5°.
16. When measured at a temperature of 0° under one atmosphere of pressure, which weighs more-a liter of oxygen or air?
C. they weigh the same
D. this cannot be determined from the information provided
17. What is the boiling point of oxygen under ordinary atmospheric pressure?
In the earlier days of chemistry there was much discussion as to whether the composition of a given compound is always precisely the same or whether it is subject to some variation. Two Frenchmen, Berthollet and Proust, were the leaders in this discussion, and a great deal of most useful experimenting was done to decide the question. Their experiments, as well as all succeeding ones, have shown that the composition of a pure chemical compound is always exactly the same. Water obtained by melting pure ice, condensing steam, burning hydrogen in oxygen, has always 11.18% hydrogen and 88.82% oxygen in it. Red oxide of mercury, from whatever source it is obtained, contains 92.6% mercury and 7.4% oxygen. This truth is known as the law of definite composition, and may be stated thus: The composition of a chemical compound never varies.
18. The chemical composition of water is always:
A. 11.18% hydrogen, 7.4% oxygen
B. 50% ice, 50% water
C. 92.6% mercury, 7.4% oxygen
D. 11.18% hydrogen, 88.82% oxygen
19. What chemicals make up red oxide of mercury?
A. hydrogen and mercury
B. hydrogen and oxygen
C. mercury and oxygen
D. hydrogen, oxygen, and mercury
20. The law of definite composition states that:
A. Berthollet and Proust were geniuses.
B. Water can be obtained from melting ice, condensing steam, or burning hydrogen in oxygen.
C. Experimentation is the only way to identify the composition of a chemical compound.
D. The composition of a chemical compound never varies.