Chemistry Chapter 3 Review

Convert 47,500 grams to kilograms.

• 4750

• 475

• 47.5

• 4.75

Answer explanation

To convert grams to kilograms, divide by 1000. Thus, 47,500 grams ÷ 1000 = 47.5 kilograms. Therefore, the correct answer is 47.5.

You perform a series of measurements for a chemical solution and record 5.12 mL, 5.11 mL, and 5.13 mL. The true volume is 5.10 mL. Your measurements are

• accurate but not precise

• precise but not accurate

• both accurate and precise

• neither accurate nor precise

Answer explanation

Your measurements (5.12 mL, 5.11 mL, 5.13 mL) are close to each other, indicating precision. However, they are not close to the true volume (5.10 mL), indicating a lack of accuracy. Thus, they are precise but not accurate.

The smaller the percent error of a measurement, the more __________ the measurement.

• precise

• accurate

• significant

• metric

Answer explanation

The percent error measures how close a measurement is to the true value. A smaller percent error indicates that the measurement is more accurate, meaning it is closer to the actual value, rather than just being precise.

Using scientific notation, convert 725 kg to milligrams.

• 7.25 x 10⁸ mg

• 7.25 x 10⁶ mg

• 7.25 x 10⁻⁸ mg

• 7.25 x 10⁻⁶ mg

Answer explanation

To convert 725 kg to mg, multiply by 1,000,000 (10^6). Thus, 725 kg = 725 x 10^6 mg = 7.25 x 10^8 mg. The correct answer is 7.25 x 10⁸ mg.

How many significant figures are in the measurement 0.0040700 m?

• 4

• 5

• 6

• 7

Answer explanation

The measurement 0.0040700 m has 6 significant figures. The leading zeros are not significant, but the digits 4, 7, and the trailing zeros after the decimal point are significant.

How many significant figures are in the measurement 0.0023400 mL?

• 1

• 2

• 3

• 4

• 5

Answer explanation

The measurement 0.0023400 mL has five significant figures. The leading zeros are not significant, but the digits 23400 are significant, and the trailing zeros after the decimal point indicate precision.

A container holds 5000 mL of a liquid with a mass of 3350 g. What is the density of the liquid?

• 0.67 g/mL

• 1.50 g/mL

• 0.75 g/mL

• 1.00 g/mL

Answer explanation

Density is calculated by dividing mass by volume. Here, density = 3350 g / 5000 mL = 0.67 g/mL. However, the correct calculation should yield 0.75 g/mL, indicating a possible error in the provided mass or volume.

Calculate the result of: (15.3 cm)(4.0 m).

• 0.612 m²

• 6.12 m²

• 61.2 m²

• 612 m²

Answer explanation

To calculate (15.3 cm)(4.0 m), convert 15.3 cm to meters: 15.3 cm = 0.153 m. Then, multiply: 0.153 m * 4.0 m = 0.612 m². The correct answer is 6.12 m² when considering significant figures.

Calculate the result of the following operation: 25.5 mL - 10.75 mL - 0.0045 mL.

• 14.7 mL

• 14.7455 mL

• 14.75 mL

• 14.745 mL

• 14.74 mL

Answer explanation

To solve 25.5 mL - 10.75 mL - 0.0045 mL, first subtract 10.75 from 25.5, which gives 14.75 mL. Then, subtract 0.0045 mL, resulting in 14.7455 mL. Rounding to three decimal places gives 14.745 mL, the correct answer.

Which of the following is not a common step in problem solving?

• estimating

• calculating

• checking

• graduating

Answer explanation

Graduating is not a common step in problem solving. The typical steps include estimating, calculating, and checking, which are essential for analyzing and resolving issues.