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Ch.1 - Matter, Measurement & Problem Solving

Tro 4th Edition

Ch.1 - Matter, Measurement & Problem Solving

Problem 112

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Chapter 1, Problem 112

Why does a temperature measurement of 25 °C have three significant figures, while a temperature measurement of -196 °C only has two significant figures? Explain.

Verified step by step guidance

1

<Understand the concept of significant figures: Significant figures are the digits in a measurement that are known with certainty plus one estimated digit.>

<Identify the significant figures in positive temperatures: For 25 °C, the digits '2' and '5' are known with certainty, and there is no decimal point, so both are significant, giving us two significant figures. The absence of a decimal point implies that the zero is not significant.>

<Identify the significant figures in negative temperatures: For -196 °C, the digits '1', '9', and '6' are known with certainty, and there is no decimal point, so all three are significant, giving us three significant figures.>

<Consider the role of the negative sign: The negative sign in -196 °C is not a digit and does not affect the count of significant figures.>

<Conclude the explanation: The difference in significant figures arises from the presence or absence of a decimal point and the certainty of the digits, not from the negative sign.>

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Related Practice

Suppose you design a new thermometer called the X thermometer. On the X scale, the boiling point of water is 130 °X, and the freezing point of water is 10 °X. At what temperature are the readings on the Fahrenheit and X thermometers the same?

Textbook Question

On a new Jekyll temperature scale, water freezes at 17 °J and boils at 97 °J. On another new temperature scale, the Hyde scale, water freezes at 0 °H and boils at 120 °H. If methyl alcohol boils at 84 °H, what is its boiling point on the Jekyll scale?

Textbook Question

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Textbook Question

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