Math in chemistry Flashcards
How do you calculate the number of significant figures in a number?
Significant figures is the number of digits in a number:
234 = 3 sig figs
2938 = 4 sig figs
219.384 = 6 sig figs
However trailing zeroes are not counted unless there’s a decimal point
8000 = 1 sig fig
8080 = 3 sig figs
8000. = 4 sig figs (because of the decimal point)
80,000.00 = 7 sig figs
Leading zeroes are also not counted
0.01 = 1 sig fig
0.001 = 1 sig fig
0.182 = 3 sig figs
How do convert celsius to Fahrenheit?
F = 1.8c + 32
Example: 100 celsius to Fahrenheit = 1.8 * 100 + 32 = 212
How do you calculate Fahrenheit to celsius?
C = (F - 32)/1.8
Example: 98 F –> C = 66/1.8 = 36.7 c
How do you convert celsius to kelvin?
K = C + 273.15
Example: 7C –> K = 7 + 273.15 = 280.15
How do you convert kelvin to celsius?
C = K - 273.15
Example: 283.15K –> C = 10
How do you convert for Fahrenheit to kelvin?
K = (F-32)/1.8 + 273.15
Example: 200 F = 366.483 K
How do you convert from kelvin to Fahrenheit?
F = (K - 273.15) * 1.8 + 32
How do you convert from feet to inches?
1ft = 12 in
How do you convert from feet to yards?
3ft = 1yd
How do you convert from inches to centimetres?
1in = 2.54cm
How do you convert from kilometres to metres?
1km = 1000m
How do you convert from metres to centimetres?
1m = 100cm
How do you convert from mile to kilometres?
1mi = 1.609km
How do you convert from miles to feet?
1mi = 5280ft
How do you convert from kilograms to grams?
1kg = 1000g
How do you convert from kilograms to pounds?
1kg = 2.2lb
How do you convert from pounds to ounces?
1lb = 16oz
How do you convert from tons to pounds?
1 ton = 2000lb
How do you convert from metric tons to kilograms?
1 metric ton = 1000kg
How do you convert from metric tons to pounds?
1 metric ton = 2204lb
How do you convert from litres to millilitres?
1L = 1000ml
How do you convert from millilitres to cubic centimetres?
1mL = 1 cm^3
How do you convert from cubic metres to litres?
1m^3 = 1000L
How do you convert from gallons to litres?
1gal = 3.785L
How do you convert from gallons to quarts?
1 gallon = 4 qt
How do you convert from quarts to pints?
1 qt = 2 pints
What’s the difference between accuracy and precision?
Accuracy is how close your answer is to the right answer
Precision is how much your data agrees with itself.
How do you calculate density?
D = M/V
How do you convert from atmospheric pressure to pascals?
1 atm (standard sea level) = 10135 pascals
How do you convert from mL to grams given the density of the thing you’re converting?
G = (N. of mL) x (N. of grams per mL)
