# Labpaq Math Lab

**Topics:**Significant figures, Decimal, Accuracy and precision

**Pages:**7 (1518 words)

**Published:**September 11, 2013

Pre-Lab Questions:

1. The rules concerning handling significant figures are as follows: When dividing/multiplying

The answer has no more significant digits than the number with the fewest significant digits (the least precise figure). Round off after calculations have been performed.

When adding/subtracting

Answer has no more places than the addend, minuend, or subtrahend with the fewest number of decimal places. Significant figures are irrelevant when adding/subtracting (least number of decimal places rule). 2. The concepts for using scientific notation is to allow the student a form to asses the order of magnitude and to visually decrease the zeros. It allows the student to compare very large or very small numbers and to better understand those numbers. Scientific notation also tells us about significant figures. An example of scientific notation would be the age of the earth.

Example:

The approximate age of the earth is 4,600,000,000 years old. Using scientific notation this number would look like 4.6 * 10^9. Scientific notation is shorter and easier to read than 4,600,000,000. 3. The rules for handling scientific notation are as follows: If the co-efficient is greater than one the exponent will be positive. If the co-efficient is less than one the exponent will be negative. The base must be 10.

The exponent must show the number of decimal places that the decimal needs to be moved to change the number to standard notation. Trailing zeros are significant . Leading zeros are not significant. The decimal place in the beginning goes after the first non zero digit. Example:

Convert 60,300,000 to scientific notation

Coefficient is greater than one. Decimal place goes after the first non zero number. Note that 6.03 is greater than one. The base must be 10. Therefore, 6.03 * 10

Exponent must show the number of decimal places.

6.03 * 10^7

Purpose:

Math Practice Lab is meant to give the basic chemistry student an opportunity to become familiar with necessary math skills that are commonly used in science. These abilities include the chance to demonstrate the use of scientific notation, algebra, density calculations and the use of conversion formulas. Procedure and Data Sheets:

Before coming to lab read the practice lab in advance. Complete any assignments that are due before the beginning of the math lab. Familiarize your self with the most common tables used in chemistry such as, the Base SI units, Derived SI units and with the Greek Prefixes used with SI units. Knowledge of formulas such that of density, mass and volume are recommended. Being able to use conversion factors are of great importance to succeeding in chemistry. When using the unit factor method for solving problems make sure to not skip steps. When answering questions make sure your calculation is correct and express the answer using the correct scientific notation and significant figures. When using units make sure to follow with the accurate abbreviations. Make sure to follow the rules when working problems that involve algebra. Make sure that you bring your calculator, plenty of paper and pens to the math practice lab.

Base SI Units Used in Chemistry

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Derived SI Units

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Greek Prefixes Used with SI Units

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Commonly Used Formulas

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Conversion Factors

( not all conversion factors are included)

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Observations:

Precision and Accuracy are highly important when coming up with a measured value. Precision is the closeness of a series of measurements to one another. Accuracy is the measure of correctness. The closeness of a measured result to the true value. Uncertainty is indicated by the number of digits in a measurement. Retaining the least uncertainty is priority. Rules for determining the number of significant figures are: All non zero digits are significant.

Zeros between zero digits are significant.

Leading zeros are never significant.

Trailing...

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