Ch.1 - Introduction: Matter, Energy, and Measurement

Problem 2

Chapter 1, Problem 2

Which of the following diagrams represents a chemical change?

Verified step by step guidance

Understand the difference between a physical change and a chemical change. A chemical change results in the formation of one or more new substances with different properties, while a physical change affects only the physical properties without changing the substance's identity.

Look for signs of a chemical change in the diagrams, such as color change, gas production (bubbles), formation of a precipitate, temperature change, or a change in composition indicating new substances formed.

Identify if the diagram shows breaking and forming of chemical bonds, which is a hallmark of chemical changes, as opposed to just changes in state or shape which are physical changes.

Eliminate diagrams that only show physical changes like melting, freezing, dissolving, or mixing without new substances being formed.

Select the diagram that clearly depicts a chemical reaction or transformation, such as reactants turning into products with different chemical formulas or evidence of a chemical reaction.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Chemical Change

A chemical change involves the transformation of substances into new products with different chemical properties and compositions. Indicators include color change, gas production, formation of a precipitate, or energy change. Unlike physical changes, chemical changes are usually irreversible.

Physical Change

A physical change affects the form or appearance of a substance without altering its chemical identity. Examples include changes in state (melting, freezing), shape, or size. Physical changes are generally reversible and do not produce new substances.

Interpreting Diagrams of Chemical Processes

Diagrams representing chemical changes often show reactants converting into different products, sometimes with symbols indicating energy changes or gas release. Understanding these visual cues helps distinguish chemical changes from physical ones by identifying new substances or bonds formed.

Recommended video:

Guided course

03:22

Energy Diagrams and Stability

Related Practice

Textbook Question

Which of the following figures represents (b) a mixture of two elements, (More than one picture might fit each description.)

186

views

Textbook Question

Which of the following figures represents (c) a pure compound, (More than one picture might fit each description.)

260

views

Textbook Question

Which of the following figures represents (d) a mixture of an element and a compound? (More than one picture might fit each description.)

661

views

Textbook Question

Musical instruments like trumpets and trombones are made from an alloy called brass. Brass is composed of copper and zinc atoms and appears homogeneous under an optical microscope. The approximate composition of most brass objects is a 2:1 ratio of copper to zinc atoms, but the exact ratio varies somewhat from one piece of brass to another. (a) Would you classify brass as an element, a compound, a homogeneous mixture, or a heterogeneous mixture?

Consider the two spheres shown here, one made of silver and the other of aluminum. (a) What is the mass of each sphere in kg?

views

Textbook Question

Consider the two spheres shown here, one made of silver and the other of aluminum. (a) What is the mass of each sphere in kg?

views