Uncertainties and Measurement Errors Pt 1
Amount of significant figures in 298.43?
5
What is the formula for percentage error?
(|measured - true|/true) x 100
What does m stand for in the equation of a line?
the gradient or slope
What does IHD stand for?
Index of Hydrogen deficiency
Which has a shorter wavelength: infrared or ultraviolet
ultaviolet
The result of multiplication or division should be expressed using the _____ number of significant figures. (larger or smallest)
Smallest
What is the symbol for absolute uncertainty
ΔA
What axis do you put the independent variable on?
x-axis
How many double bonds are in benzene?
3 double bonds
True or False: 1 ring = 1 IHD
True
What are the numbers after the decimal called?
The mantissa
What is one way to reduce random errors
Repeating measurements
When the variables either increase or decrease parallel to each other. (What type of correlation?)
Positive correlation
Name 2 regions of the EMS
x-rays, radio raves, infrared, visible & uv light, microwaves, etc
What is the name for this law: F = - kx
Hooke's law
What is the typical uncertainty of a school balance?
0.01 g
What are the three ways systematic errors can be classified?
Instrumentation error, experimental methodology error and personal error
Name two ways to find the intercept of a line
extrapolation and using the equation of a line
Why do different molecules absorb IR radiation at different frequencies?
The energy required to vibrate depends on bond enthalpy
Name the 3 types of spectroscopy
Infrared, H NMR, Mass
What is the difference between precision and accuracy?
Precision is the closeness of the test results while accuracy is the closeness of the test results to the true value.
What could be an actual value for 32.7 ± 0.9 cm^3
Anywhere between 31.8 and 33.6 cm^3
What is the relationship of variables when the correlation coefficient is -1?
It shows that the relationship is a negative linear gradient
Deduce the IHD for a molecule of molecular formula C2H5NO
1
Which type of spectroscopy is used to give information about the types of bonds in a molecule?
Infrared