Sig Figs
When adding/subtracting numbers the sig figs rule is
least accurate past the decimal point
781 mL = ? L
.781L
What is the equation used to calculate phase change energy?
q=mC(deltaT)
An atom is how many types of elements?
one
What is a mole?
6.02x10^23 atoms of any given element
When multiplying/dividing sig figs the rule is
How many milliliters are in a 12 oz soda can?
(1 oz= 29.5735mL)
354.9 mL
What is the calculation used to calculate energy during a time of no phase change?
q=m(deltaH) or q=m(E(f)-E(i))
What is the unit of mass of atoms?
AMU
How many atoms are in a 5.67 mole sample of Cu?
3.41 x 1024atoms
3.099 + 1.02 =
Use sig fig rule and rounding
4.12
4.18 kg = ? g
4180 g
A 145 g sample of an unknown substance was heated from 25.0ºC to 45.0ºC with the absorption of 5750 J of energy. What is the specific heat of the substance?
1.98 J/ g*C
5 or five
How many molecules are in 0.0034 mole of water?
2.0 x 1021 m-c
64.76 / 8.1 =
Use sig fig and rounding rules
8.0
The label on a soft drink bottle gives the volume in two units: 2.0 L and 67.6 fl oz. Use this information to derive a conversion factor between the English and metric units.
2.0L/67.6floz.=0.030L/1floz.
When the products are below the reactants what type of reaction took place?
exothermic reaction
When modeling with Bohr Models how many electrons can go into shell 1 and shell 6?
Shell 6 = 2e-
How many atoms are in a 3.4 gram sample of gold?
grams to moles--> moles to atoms
1.0 x 1022atoms
100 / (32.0- 22)
10
If you get 8 hours of sleep a night and you sleep everyday for a year how many seconds have you slept?
10, 512, 000 seconds
If a 234.5 gram solid was heated from 23.6*C to 100*C and it took 438,399 Joules of energy what is the specific heat of the solid?
specific heat of 24.47J/g*C
what is the mass of an electron?
negligible and offers no mass to the atom
4.51 x 1023 molecules of fluorine gas would have a mass of _________________ g.
molecules to moles --> moles to grams
28.5 g