Q: A chemist needs to convert 2.50 meters to inches. Which conversion factors should be used in sequence?

$$1\,m = 100\,cm$$ \text{ and } 1\,in = 2.54\,cm$

Question 1

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more different kinds of elements in a fixed ratio.

Question 2

Which of the following is an example of an intensive property?

Accepted Answer

Density

Question 3

A student separates a mixture of sand and salt by adding water, filtering, and then evaporating the water from the filtrate. Which separation techniques are used in this process?

Accepted Answer

Filtration and evaporation

Question 4

Which of the following changes is a chemical change?

Accepted Answer

Burning of gasoline

Question 5

A sample of water is heated from 25 $$^{\circ}C to 100$$ $$^{\circ}C. $$What is the temperature change in Kelvin?

Accepted Answer

$$100 + 273.15 - (25 + 273.15) = 75 K$$

Question 6

Which of the following is the correct formula for density?

Accepted Answer

$$D = m/V$$

Question 7

A solution is prepared by dissolving 10 g of NaCl in 90 g of water. Which term best describes this mixture?

Accepted Answer

Homogeneous mixture (solution)

Question 8

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros between nonzero digits are significant.

Question 9

Convert 25.0 $$^{\circ}C to $$Fahrenheit using the correct formula.

Accepted Answer

$$^{\circ}F = \frac{9}{5}(25.0) + 32$$

Question 10

A student measures the mass of a sample three times and gets values very close to each other, but far from the true value. This is an example of:

Accepted Answer

Low accuracy, high precision

Question 11

Which of the following is NOT a base SI unit?

Accepted Answer

Liter

Question 12

Which of the following best describes the Law of Constant Composition?

Accepted Answer

The relative number of atoms of each element in a compound is the same in any sample.

Question 13

A graduated cylinder contains 25.0 mL of water. A metal object is added, raising the water level to 32.5 mL. If the mass of the object is 60.0 g, what is its density?

Accepted Answer

$$D = \frac{60.0\,g}{7.5\,mL}$$

Question 14

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 15

Which separation technique would be most effective for separating a mixture of two liquids with different boiling points?

Accepted Answer

Distillation

Question 16

How many significant figures are in the measurement 0.004560 g?

Accepted Answer

4

Question 17

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 18

A chemist needs to convert 2.50 meters to inches. Which conversion factors should be used in sequence?

Accepted Answer

$$1\,m = 100\,cm$$ 	ext{ and } 1\,in = 2.54\,cm$

Question 19

Which of the following is a derived SI unit?

Accepted Answer

Liter

Chapter 1: Introduction to Matter, Measurement, and Chemical Foundations

Guida di studio - Domande di pratica

Study guide - Flashcard