Chemistry Essay
Significant Figures are very important when reporting scientific data because they give us knowledge of how well we can actually measure data. Before getting into the calculations we must first understand the rules for counting significant figures. 1. All nonzero digits are significant.
Example: 547 (3 sig. figs.)
2. Zeros in a number between non-zero digits are always significant.
Example: 4308 (4 sig. figs.)
3. Trailing zeros to the right of a decimal point are significant.
Example: 4.00 (3 sig. figs.)
4. Leading zeros are not significant.
Example: 0.000045 (2 sig. figs.)
5. Measured values that have trailing zeros only to the left of the decimal point are ambiguous and should be expressed in scientific notation.
We must take note that the chemistry textbook (Silberberg 6e) states that placing a decimal point to the right of some trailing zeros (example: 300.) will make the zeros significant. However in General Chemistry, we do not follow this rule. If we want to write a whole number with trailing zeros we must use scientific notation to show which zeros are significant.
When making calculations, significant figures are critical. We must be careful in reporting the number of significant in a multistep calculation such as addition and subtraction, as well as multiplication and division. The rules for these calculations are a little different.
The Addition/Subtraction Rule: round your answer off to the same DECIMAL PLACE as the least precise piece of data that was involved in the calculation (including conversion factors that depend upon measurements rather than definitions and those that have been rounded off, e.g., 1 mile ≈ 1.6X103 m).
The Addition/Subtraction Rule states to: round your answer off to the same decimal place as the least precise piece of data that is involved in the calculation (including “measured” conversion factors). For example, if I have 170.0 g of H2O and I also have 0.205 g salt, and I ask how many grams
Example: 547 (3 sig. figs.)
2. Zeros in a number between non-zero digits are always significant.
Example: 4308 (4 sig. figs.)
3. Trailing zeros to the right of a decimal point are significant.
Example: 4.00 (3 sig. figs.)
4. Leading zeros are not significant.
Example: 0.000045 (2 sig. figs.)
5. Measured values that have trailing zeros only to the left of the decimal point are ambiguous and should be expressed in scientific notation.
We must take note that the chemistry textbook (Silberberg 6e) states that placing a decimal point to the right of some trailing zeros (example: 300.) will make the zeros significant. However in General Chemistry, we do not follow this rule. If we want to write a whole number with trailing zeros we must use scientific notation to show which zeros are significant.
When making calculations, significant figures are critical. We must be careful in reporting the number of significant in a multistep calculation such as addition and subtraction, as well as multiplication and division. The rules for these calculations are a little different.
The Addition/Subtraction Rule: round your answer off to the same DECIMAL PLACE as the least precise piece of data that was involved in the calculation (including conversion factors that depend upon measurements rather than definitions and those that have been rounded off, e.g., 1 mile ≈ 1.6X103 m).
The Addition/Subtraction Rule states to: round your answer off to the same decimal place as the least precise piece of data that is involved in the calculation (including “measured” conversion factors). For example, if I have 170.0 g of H2O and I also have 0.205 g salt, and I ask how many grams