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Problem 1
Pure acetic acid, which gives the sour taste to vinegar, has a melting point of 16.7 °C and a boiling point of 118 °C . Predict the physical state of acetic acid when the ambient temperature is 10 °C .
Problem 21
Assuming that Coca-Cola has the same specific heat as water, how much energy in calories is removed when 350 g of Coca-Cola (about the contents of one 12 oz can) is cooled from room temperature (25 °C) to refrigerator temperature (3 °C)?
Problem 29a
What is the specific gravity of the following solution?
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Problem 32
Assume that you are delivering a solution sample from a pipette. Figures (a) and (b) show the volume level before and after dispensing the sample, respectively. State the liquid level (in mL) before and after dispensing the sample, and calculate the volume of the sample.
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Problem 33
Assume that identical hydrometers are placed in ethanol (sp gr 0.7893) and in chloroform (sp gr 1.4832). In which liquid will the hydrometer float higher? Explain.
Problem 34
What is the difference between a physical change and a chemical change?
Problem 37
Name and describe the three states of matter.
Problem 38
Name two changes of state and describe what causes each to occur.
Problem 40
Butane (C4H8) is an easily compressible gas used in cigarette lighters. It has a melting point of and a boiling point of -138.4 °C and a boiling point of -0.5 °C. Would you expect a butane lighter to work in winter when the temperature outdoors is 25 °F? Why or why not?
Problem 42
Which of these terms, (i) mixture, (ii) solid, (iii) liquid, (iv) gas, (v) chemical element, (vi) chemical compound, applies to the following substances at room temperature?
a. Gasoline
b. Iodine
c. Water
d. Air
e. Blood
f. Sodium bicarbonate
g. Gaseous ammonia
h. Silicon
Problem 43b
Hydrogen peroxide, often used in solutions to cleanse cuts and scrapes, breaks down to yield water and oxygen: Hydrogen peroxide, H2O2(aq) → Hydrogen, H2(g) + Oxygen, O2(g)
b. Which of the substances are chemical compounds, and which are elements?
Problem 51
Glucose, a form of sugar, has the formula C6H12O6. Which elements are included in this compound, and how many atoms of each are present?
Problem 52
Write the formula for ibuprofen: 13 carbons, 18 hydrogens, and 2 oxygens. What are the common uses of ibuprofen?
Problem 54
What is the difference between a physical quantity and a number?
Problem 56
Give the full name of the following units:
a. cc
b. dm
c. mm
d. nL
e. mg
f. m3
Problem 78a
The white blood cell concentration in normal blood is approximately 12,000 cells/mm3 of blood. How many white blood cells does a normal adult with 5 L of blood have? Express the answer in scientific notation.
Problem 82
Calculate the specific heat of copper if it takes 23 cal (96 J) to heat a 5.0 g sample from 25 °C to 75 °C.
Problem 83
The specific heat of fat is 0.45 cal/(g ⋅ °C) (1.9 J/g °C) and the density of fat is 0.94 g/cm3. How much energy (in calories and joules) is needed to heat 10 cm3 of fat from room temperature (25 °C) to its melting point (35 °C)?
Problem 85
When 100 cal (418 J) of heat is applied to a 125 g sample, the temperature increases by 28 °C. Calculate the specific heat of the sample and compare your answer to the values in Table 1.10. What is the identity of the sample?
Problem 93
A white solid with a melting point of 730 °C is melted. When electricity is passed through the resultant liquid, a brown gas and a molten metal are produced. Neither the metal nor the gas can be broken down into anything simpler by chemical means. Classify each—the white solid, the molten metal, and the brown gas—as a mixture, a compound, or an element.
Problem 94
Refer to the pencil in Problem 1.31. Using the equivalent values in Table 1.8 as conversion factors, convert the length measured in inches to centimeters. Compare the calculated length in centimeters to the length in centimeters measured using the metric ruler. How do the two values compare? Explain any differences.
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Problem 95
Gemstones are weighed in carats, where 1 carat = 200 mg exactly. What is the mass in grams of the Hope diamond, the world's largest blue diamond, at 44.4 carats?
Problem 96a
The relationship between the nutritional unit for energy and the metric unit is 1 Calorie = 1 kcal.
a. One donut contains 350 Calories. Convert this to calories and joules.
Problem 103b
Today, thermometers containing mercury are used less frequently than in the past because of concerns regarding the toxicity of mercury and because of its relatively high melting point (-39 °C). This means that mercury thermometers cannot be used in very cold environments because the mercury is a solid under such conditions. Alcohol thermometers, however, can be used over a temperature range from -115 °C (the melting point of alcohol) to 78.5 °C (the boiling point of alcohol).
b. The densities of alcohol and mercury are 0.79 g/mL and 13.6 g/mL, respectively. If the volume of liquid in a typical laboratory thermometer is 1.0 mL, what mass of alcohol is contained in the thermometer? What mass of mercury?
Problem 105
A patient is receiving 3000 mL/day of a solution that contains 5 g of dextrose (glucose) per 100 mL of solution. If glucose provides 4 kcal/g of energy, how many kilocalories per day is the patient receiving from the glucose?
Problem 108
When 1.0 tablespoon of butter is burned or used by our body, it releases 100 kcal (100 food Calories or 418.4 kJ) of energy. If we could use all the energy provided, how many tablespoons of butter would have to be burned to raise the temperature of 3.00 L of water from 18.0 ℃ to 90.0 ℃
Problem 109
An archeologist finds a 1.62 kg goblet that she believes to be made of pure gold. When 1350 cal (5650 J) of heat is added to the goblet, its temperature increases by 7.8 ℃. Calculate the specific heat of the goblet. Is it made of gold? Explain.