/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 6 If you place a glass rod over a ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

If you place a glass rod over a burning candle, the glass appears to turn black. What is happening to each of the following (physical change, chemical change, both, or neither) as the candle burns? Explain each answer. a. the wax b. the wick c. the glass rod

Short Answer

Expert verified
a. The wax undergoes both physical and chemical changes. It melts due to heat (physical change) and reacts with oxygen to produce carbon dioxide and water vapor (chemical change). b. The wick undergoes both physical and chemical changes. It absorbs the liquid wax (physical change) and reacts with oxygen releasing carbon dioxide and water vapor (chemical change). c. The glass rod undergoes a physical change. Its appearance turns black due to the deposition of soot, which can be cleaned off, but there is no chemical change.

Step by step solution

01

a. The wax

When the candle burns, the wax melts due to heat, which is a physical change because it only alters the state of the wax from solid to liquid. However, the heat from the flame also causes the wax molecules to react with oxygen, producing carbon dioxide and water vapor, which is a chemical change. So, the wax undergoes both physical and chemical changes.
02

b. The wick

The wick absorbs the liquid wax and provides fuel to continue the burning process, which is a physical change as it only takes up the wax. However, as the wick burns, it reacts with oxygen, and the combustion results in the release of carbon dioxide and water vapor, which is a chemical change. Therefore, the wick undergoes both physical and chemical changes.
03

c. The glass rod

As for the glass rod, it undergoes a physical change when it is placed over the burning candle. The glass appears to turn black due to the deposition of soot (unburned carbon particles) from the burning process on its surface. This change is only a temporary alteration of appearance and can be cleaned off, so the glass undergoes a physical change but no chemical change.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A \(25.00-\mathrm{g}\) sample of a solid is placed in a graduated cylinder and then the cylinder is filled to the \(50.0-\mathrm{mL}\) mark with benzene. The mass of benzene and solid together is \(58.80 \mathrm{~g}\). Assuming that the solid is insoluble in benzene and that the density of benzene is \(0.880 \mathrm{~g} / \mathrm{cm}^{3}\), calculate the density of the solid.

Perform the following mathematical operations, and express each result to the correct number of significant figures. a. \(\frac{0.102 \times 0.0821 \times 273}{1.01}\) b. \(0.14 \times 6.022 \times 10^{23}\) c. \(4.0 \times 10^{4} \times 5.021 \times 10^{-3} \times 7.34993 \times 10^{2}\) d. \(\frac{2.00 \times 10^{6}}{3.00 \times 10^{-7}}\)

Perform the following unit conversions. a. 908 oz to kilograms b. \(12.8 \mathrm{~L}\) to gallons c. \(125 \mathrm{~mL}\) to quarts d. \(2.89\) gal to milliliters e. \(4.48 \mathrm{lb}\) to grams f. \(550 \mathrm{~mL}\) to quarts

For a material to float on the surface of water, the material must have a density less than that of water \((1.0 \mathrm{~g} / \mathrm{mL})\) and must not react with the water or dissolve in it. A spherical ball has a radius of \(0.50 \mathrm{~cm}\) and weighs \(2.0 \mathrm{~g}\). Will this ball float or sink when placed in water? (Note: Volume of a sphere \(=\frac{4}{3} \pi r^{3}\).)

A thermometer gives a reading of \(96.1^{\circ} \mathrm{F} \pm 0.2^{\circ} \mathrm{F}\). What is the temperature in \({ }^{\circ} \mathrm{C}\) ? What is the uncertainty?

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.