Q: How many fluid ounces are in a 4 L bottle? (Given: 1 gallon = 3.785 L, 1 quart = 2 pints, 1 pint = 16 fl. oz, 1 L = 1000 cm³)

$$4\ \text{L} \times \frac{1\ \text{gallon}}{3.785\ \text{L}} \times \frac{4\ \text{quarts}}{1\ \text{gallon}} \times \frac{2\ \text{pints}}{1\ \text{quart}} \times \frac{16\ \text{fl. oz}}{1\ \text{pint}} = 216.96\ \text{fl. oz}$$

Q: A cylindrical object with a radius of 4.02 cm and a height of 6 cm has a mass of 2.2 lbs. What is the density of this object in g/cm³? (1 lb = 454 g)

$$\text{Density} = \frac{2.2\ \text{lb} \times 454\ \text{g/lb}}{\pi \times (4.02\ \text{cm})^2$ \times 6\ \text{cm}} = \frac{998.8\ \text{g}}{304.8\ \text{cm}^3} = 3.28\ \text{g/cm}^3$$

Q: A urine sample has a specific gravity of 1.039. If the density of water is 1.00 g/mL, what is the density of the urine?

$$\text{Density of urine} = \text{Specific gravity} \times \text{Density of water} = 1.039 \times 1.00\ \text{g/mL} = 1.039\ \text{g/mL}$$

Q: A student calculates the percent error for a measurement as follows: measured value = 8.50 g, true value = 8.00 g. What is the percent error?

$$\text{Percent error} = \frac{8.50 - 8.00}{8.00} \times 100\% = 6.25\%$$

Question 1

Which of the following statements best describes the difference between mass and weight?

Accepted Answer

Mass is the amount of matter in an object, while weight is the force exerted on that object by gravity, calculated as $$W = 	ext{mass} 	imes 	ext{gravity}.$$

Question 2

A thermometer reads 98.6°F. What is this temperature in Kelvin?

Accepted Answer

$$K = \frac{5}{9}(98.6 - 32) + 273.15 = 310.15\ K$$

Question 3

Which of the following numbers has three significant figures?

Accepted Answer

0.0205

Question 4

A student measures the length of a metal rod three times and gets values of 12.45 cm, 12.47 cm, and 12.46 cm. What does this indicate about the precision and accuracy of the measurements?

Accepted Answer

The measurements are precise but may not be accurate if the true value is different.

Question 5

How many fluid ounces are in a 4 L bottle? (Given: 1 gallon = 3.785 L, 1 quart = 2 pints, 1 pint = 16 fl. oz, 1 L = 1000 cm³)

Accepted Answer

$$4\ 	ext{L} 	imes \frac{1\ 	ext{gallon}}{3.785\ 	ext{L}} 	imes \frac{4\ 	ext{quarts}}{1\ 	ext{gallon}} 	imes \frac{2\ 	ext{pints}}{1\ 	ext{quart}} 	imes \frac{16\ 	ext{fl. oz}}{1\ 	ext{pint}} = 216.96\ 	ext{fl. oz}$$

Question 6

Which of the following is an example of an exact number?

Accepted Answer

100 cm in 1 m

Question 7

A cylindrical object with a radius of 4.02 cm and a height of 6 cm has a mass of 2.2 lbs. What is the density of this object in g/cm³? (1 lb = 454 g)

Accepted Answer

$$	ext{Density} = \frac{2.2\ 	ext{lb} 	imes 454\ 	ext{g/lb}}{\pi 	imes (4.02\ 	ext{cm})^2$ 	imes 6\ 	ext{cm}} = \frac{998.8\ 	ext{g}}{304.8\ 	ext{cm}^3} = 3.28\ 	ext{g/cm}^3$$

Question 8

Which SI base unit is used to measure luminous intensity?

Accepted Answer

candela (cd)

Question 9

A urine sample has a specific gravity of 1.039. If the density of water is 1.00 g/mL, what is the density of the urine?

Accepted Answer

$$	ext{Density of urine} = 	ext{Specific gravity} 	imes 	ext{Density of water} = 1.039 	imes 1.00\ 	ext{g/mL} = 1.039\ 	ext{g/mL}$$

Question 10

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros between nonzero digits are always significant.

Question 11

A measurement is recorded as 0.00250 g. How many significant figures does this value have?

Accepted Answer

4

Question 12

Which metric prefix represents $$10^{-6}$$?

Accepted Answer

micro

Question 13

A student calculates the percent error for a measurement as follows: measured value = 8.50 g, true value = 8.00 g. What is the percent error?

Accepted Answer

$$	ext{Percent error} = \frac{8.50 - 8.00}{8.00} 	imes 100\% = 6.25\%$$

Question 14

Which of the following is NOT a base SI unit?

Accepted Answer

liter (L)

Question 15

When multiplying 0.031 by 0.045, how many significant figures should the answer have?

Accepted Answer

2

Question 16

A sample of blood glucose is measured three times: 112 mg/mL, 114 mg/mL, and 116 mg/mL. What does this illustrate about scientific measurements?

Accepted Answer

All scientific measurements have some degree of uncertainty.

Question 17

Which of the following is the correct formula for converting Celsius to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 18

Which of the following is a quantitative property?

Accepted Answer

The mass of a rock

Question 19

A measurement requires both a ______ and a ______.

Accepted Answer

number; unit

Chemistry and Measurements: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard