Concept explainers
(a)
Interpretation:
The number 1.2735 should be rounded off to two significant figures.
Concept Introduction:
Significant figures are used to express the degree of accuracy of an answer. The rules for identifying significant figures are as follows:
- Non-zero digits are considered as significant figures. (1 to 9)
- Zeros between non-zero digits are considered as significant figures. (for example, 2008 has four significant figures.)
- Zeros that are left to the decimal are not considered as significant figures. (for example, 0000.28 has two significant figures.)
- On the right side of the decimal place, zeros between decimal and non-zero digits are not considered as significant figures. (for example, 0.0028 has two significant figures.)
- On the right side of the decimal place, zeros after the non-zero digits are considered as significant figures. (0.28000 has five significant figures.)
The rules for rounding off numbers are as follows:
- If the figure after the decimal is less than 5, then the digit remains unchanged.
- If the figure after the decimal is greater than 5 or equal to 5, then 1 is added to the tenths place.
- If the figure after the decimal is even, then the digit remains unchanged.
- If the figure after the decimal is odd, then 1 is added to the tenths place.
(b)
Interpretation:
The number 0.00253622 should be rounded off to two significant figures.
Concept Introduction:
Significant figures are used to express the degree of accuracy of an answer. The rules for identifying significant figures are as follows:
- Non-zero digits are considered as significant figures. (1 to 9)
- Zeros between non-zero digits are considered as significant figures. (for example, 2008 has four significant figures.)
- Zeros that are left to the decimal are not considered as significant figures. (for example, 0000.28 has two significant figures.)
- On the right side of the decimal place, zeros between decimal and non-zero digits are not considered as significant figures. (for example, 0.0028 has two significant figures.)
- On the right side of the decimal place, zeros after the non-zero digits are considered as significant figures. (0.28000 has five significant figures.)
The rules for rounding off numbers are as follows:
- If the figure after the decimal is less than 5, then the digit remains unchanged.
- If the figure after the decimal is greater than 5 or equal to 5, then 1 is added to the tenths place.
- If the figure after the decimal is even, then the digit remains unchanged.
- If the figure after the decimal is odd, then 1 is added to the tenths place.
(c)
Interpretation:
The number 3,836.9 should be rounded off to two significant figures.
Concept Introduction:
Significant figures are used to express the degree of accuracy of an answer. The rules for identifying significant figures are as follows:
- Non-zero digits are considered as significant figures. (1 to 9)
- Zeros between non-zero digits are considered as significant figures. (for example, 2008 has four significant figures.)
- Zeros that are left to the decimal are not considered as significant figures. (for example, 0000.28 has two significant figures.)
- On the right side of the decimal place, zeros between decimal and non-zero digits are not considered as significant figures. (for example, 0.0028 has two significant figures.)
- On the right side of the decimal place, zeros after the non-zero digits are considered as significant figures. (0.28000 has five significant figures.)
The rules for rounding off numbers are as follows:
- If the figure after the decimal is less than 5, then the digit remains unchanged.
- If the figure after the decimal is greater than 5 or equal to 5, then 1 is added to the tenths place.
- If the figure after the decimal is even, then the digit remains unchanged.
- If the figure after the decimal is odd, then 1 is added to the tenths place.
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General, Organic, & Biological Chemistry
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