Fundamentals of measurement

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## Fundamentals of measurement

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**Fundamentals of measurement**Due Today: 1. Fundamentals Pre-Lab 2.Fundamentals Short Report Homework: 1. Density Part-1 Pre Lab**Objective**• Refine measurement skills using instruments • Apply rules of significant figures to combine measurements for calculations**Key Terms**• Side A • Measure to the nearest 0.1 m • Side B • Measures to the nearest 0.1 dm • Side C • Measures to the nearest 0.1 cm • Side D • Measures to the nearest 0.1 mm**Procedure Notes**• Four Stations 1. Linear Measurements and Volume: • Cube • Rectangular Cuboid • Cylinder • Use calipers to measure the diameter • Units: • Volumes will be reported in cm3 or mm3**Procedure Notes**2. Density of Solids: • Cube • Rectangular Cuboid • Units: • Volumes will be reported in mm3 or cm3 • Densities will be reported in g/mm3 or g/cm3**Procedure Notes**3. Linear Measurement and Area: • Triangle • Rectangle • Parallelogram • Units: • Areas will be reported in mm2 or cm2**Procedure Notes**4. Density of Liquids: • Volume with Buret • Volumes reported to the nearest 100th mL (25.35 mL) • Volume with Graduated Cylinder • Volumes reported to the nearest 10th mL (12.5 mL) • Units: • Densities will be reported in g/mL**Waste**• Blue and Yellow liquid Down the drain • Green liquid Waste container in waste hood**Risk Assessment**• Green Solution: • Isopropyl Alcohol • Danger • Flammable Liquid • Mild Skin Irritation • Harmful if Swallowed**Equipment Notes**• Using Calipers • Make sure the calipers read zero when closed • Use the outside jaws to measure the outer diameter or width • Use the inside jaws to measure the inner diameter**Equipment Notes**• Read & record the millimeter mark just to the left of the zero on the fixed caliper 17.0 mm**Equipment notes**• Read & record the millimeter mark that lines up with the vernier scale (moveable) and the fixed scale. 0.48 mm**Equipment notes**• Add the measurements together to get an accurate reading 17 mm + 0.48 mm = 17.48 mm**Significant Figures**• ALL non-zero numbers are ALWAYS significant • (1,2,3,4,5,6,7,8,9) • ALL zeros BETWEEN non-zero numbers are ALWAYSsignificant • 1005 • 10.05**Significant Figures**• ALL zeros to the right of the decimal point AND at the end of the number are ALWAYS significant • 501.040 – zero is significant • 1200 – zeros are NOT significant • 0.0052 – zeros are NOT significant (leading zero)**Significant figures**• ALL zeros to the left of a decimal point AND in a number are ALWAYS significant • 1500.0 – zeros ARE significant • 1700.3 – zeros ARE significant • 100 – zeros are not significant**Significant figures**• Defined quantities do not limit significant figures • Unit conversions - 100 cm/m • Molar mass • Density • Values of constants do not limit significant figures • Pi - ∏ • Avogadro's number - 6.022 x1023**Significant figures**• Addition and Subtraction • The number of decimal places determines the number of significant figures**Significant figures**• Multiplication and Division • Count the number of significant figures. Round your answer to the lowest number of significant figures. 8 Significant Figures 5 Significant Figures 10 Significant Figures (from calculator)**calculations**• When doing a calculation with different units, convert to the smallest unit • Example: Side 1 : 0.5 dm→50 mm Side 2: 2.4 cm→24 mm Side 3: 24.0mm 24.0 mm 0.5 dm 2.4 cm**calculations**• Volume of cube • V = l3 • Volume of rectangular cuboid • V = l x w x h • Volume of cylinder • V = l x ∏ x r2 • Area of a Triangle • A = ½ b x h**calculations**• Area of a Rectangle/Parallelogram • A = l x w • The width of a parallelogram is NOT the other side w**Summary of calculations**• Atriangle= ½ b x h • Arectangle= l x w • D= • Vcube = l3 • Vrectangle = l x w x h • Vcylinder = l x ∏ x r2