Dressen-percent error

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% Error : 

% Error A quantitative comparison between your value (determined in an experiment) and an accepted value.

How to Calculate % Error : 

How to Calculate % Error % Error = | Theoretical value - Experimental value | Theoretical value _________________________________ Theoretical value might also be called literature value Theoretical value might also be called the accepted value X 100%

Example of % Error : 

Example of % Error A + B C We calculate that if all goes well, we should isolate 2.23 grams of C. Theoretical value = 2.23 g Now we actually do reaction but we isolate 1.26 g of C Experimental value = 1.26 % Error = (2.23 g - 1.26 g) 2.23 g _____________ X 100%

Example of % Error : 

Example of % Error A + B C We calculate that if all goes well, we should isolate 2.23 grams of C. Theoretical value = 2.23 g Now we actually do reaction but we isolate 1.26 g of C Experimental value = 1.26 % Error = 0.97 g 2.23 g _____________ X 100%

Example of % Error : 

Example of % Error A + B C We calculate that if all goes well, we should isolate 2.23 grams of C. Theoretical value = 2.23 g Now we actually do reaction but we isolate 1.26 g of C Experimental value = 1.26 % Error = X 100% 0.4349775 % Error = 43.49775 % 43.5 %

Sample Problems : 

Sample Problems Vicky made a mistake when measuring the volume of a container. She found the volume to be 70 liters. The actual value for the volume is 45 liters. What is the percent error calculated in percentage? Experimental Data: 4.0 g, 4.2 g, 4.1 g The actual value is reported to be 4.23 g. What is the percent error?

1. Linear Relationships(Directly Proportional) : 

1. Linear Relationships(Directly Proportional) When the line of best fit is linear (a straight line), the variables are directly proportional to each other. The equation y = mx + b defines the line. m represents slope b represents the y-intercept As one variable increases, so does the other. y = mx + b

2. Non-Linear Relationships:Inverse Relationship : 

2. Non-Linear Relationships:Inverse Relationship y = k/x As one variable increases, the other variable decreases “k” is called a constant: …k is whatever number “fixes” the equation and makes it true for x and y.

Density : 

Density D = M V D = density (g/ml) M = mass (g) V = volume (ml or cm3) Object 2 Mass: 20 g Volume: 2 ml Object 1 Mass: 5.0 g Volume: 3.0 cm3 Object 3 Mass: 7.0 g Volume: 10 ml Object 4 Density: .820 g/ml Volume: 15.0 ml

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