Ch 10-12
Assume STP
1) How many atoms are in 1 mole of a substance ?
2) How many liters does 1 mole of gaseous substance occupy?
3) What conversion factor do you need when converting from moles to grams ?
1) 6.02 x 10^23 atoms
2) 22.4 L
3) molar mass conversion factor.
1) Pressure and Volume are ( Directly/ Indirectly) Proportional
2) Volume and Temperature are ( Directly/ Indirectly) proportional
1) P and V are Indirectly proportional
2) V and T are directly proportional
Rank Colloid, Suspension, and Solution in terms of:
1) Increasing particle size
2) Heterogeneous/ Homogeneous
3) Tyndall effect (yes/no)
1) Smallest particles ( < 1nm ) Solution
( 1-1000nm) colloid
Largest particles ( >1000nm) Suspension
2) Heterogeneous - Suspensions and Colloids
Homogeneous - Solutions
3) Solution ( No Tyndall effect )
Suspension (Yes and no) must be very fine suspension particles to exhibit Tyndal effect.
Colloid ( Yes)
List the 6 types of radiation/decay
Alpha, Beta, Gamma radiation
Proton, Positron, Neutron Decay
Name the following compounds
Sr2S
SrSO4
Strontium Sulfide
Strontium Sulfate
50.0 g NaCl x ( 1 mole NaCl / 58.44 g NaCl ) =
0.856 moles NaCl
Why is the boiling point lower here in Colorado Springs than at sea level?
Does that mean food has to cook longer or shorter amount of time?
Boiling point is when the vapor pressure of a liquid = atmospheric pressure. Our atmospheric pressure is less than at sea level because of the higher elevation. Because our atmospheric pressure is lower, the boiling point can happen at a temperature lower than 100 Celsius.
Because the boiling point is lower here, the food must cook longer to allow the food particles enough time to gain kinetic energy ( above 165 Celsius )
List the three factors that speed up the rate of dissolving, describe them at the molecular level.
1) Stirring- increases particle motion/collisions among solute/solvent particles.
2) increasing temp- increases particle motion/collisions among solute/solvent particles.
3) Crushing ( particle size) - by crushing a substance, you create more surface area. With more surface area, there is more space for solvation.
Define Fission and Fusion
Fission- bombarding nuclei with neutrons to cause chain reaction
Fusion - combining atoms of lesser mass to to form an atom of greater mass.
Balance the equation:
Nickel (II) Nitrate + Sodium Sulfide --> Nickel (II) Sulfide + Sodium Nitrate
Ni(NO3) 2 + Na2S --> NiS + 2 NaNO3
How many atoms are in 45 grams of KCl
45 grams KCl x ( 1 mole KCl / 74.55 g KCl ) x
( 6.02 x 10^ 23 atoms KCl / 1 mole KCl) =
3.6 x 10^23 atoms KCl
If a substances pressure is increased from 5.00 Atm to 14.5 atm. What will the resulting volume be if the initial volume was 25.0 L ?
P1 x V1 = P2 x V2
5.00 atm x 25.0 L = 14.5 atm x V2
8.62 L = V2
How much water does Mr Nelson need to add to his stock solution of 12.0 M H2SO4 in 1.0 L of water if he wants to dilute it to a concentration of 2.5 M?
M1 x V1 = M2 x V2
12.0 M x 1.0 L = 2.5 M x V2
(12.0 M x 1.0 L / 2.5 M ) = V2
4.8 L = V2
Complete the following nuclear equations:
1) 6/3 Li + 1/0 n --> 0/-1 e + 4/2 He +________
2) 9/4 Be + 1/1 H --> 4/2 He +________
1) 3/2 He
2) 6/3 Li
What is the density of a 100.0 gram sample of NaCl that occupies 25.0 L ?
D=m/V
D= 100.0 g / 25.0 L
D= 4 g/l
CaCl2 + 2 NaOH --> Ca(OH)2 + 2 NaCl
Mole Ratio= 2 moles NaCl per 1 mole CaCl2
0.35 moles CaCl2 x ( 2 moles NaCl / 1 mole CaCl2) = 0.70 moles NaCl
If the initial volume a substance is 12.5 L at 20.5 degrees Celsius, what will its volume be if the temperature is reduced to 274 Kelvin?
V1/T1=V2/T2
12.5 L / 293.5 Kelvin = V2 / 274 Kelvin
11.7 L = V2
How many grams of KCl does Mr. Nelson need to mix in 1.0 L of water to create a solution with a concentration of 15.0 M?
M= n/L
15.0 M= n / 1.0 L
15.0 moles of KCl needed.
15.0 moles KCl x ( 74.55 g (molar mass) KCl/ 1 mole KCl) = 1100 grams or 1.1 x 10^3 grams
A=Ao x (1/2)^n
If the half life of Carbon-14 is 5,730 years. How much carbon-14 remains from an original sample of 100 g after 10,005 years?
n= 10,005 / 5,730 = 1.75 years
A = 100g x (1/2) ^1.75 years
A= 29.7 g
A= 30 g
How many Calories are in 40.0 Joules?
( Please answer in scientific notation)
40 Joules x ( 1 calorie / 4.184 Joules ) x ( 1 Calorie / 1000 calorie) = 9.56 x 10^-3 Calories
If lithium sulfide reacts with sodium bromide to produce sodium sulfide and lithium bromide..
1) Balance the equation
2) Calculate the mass of Lithium bromide in grams if 20.0 grams of lithium sulfide reacts with excess sodium bromide.
1) Li2S + 2 NaBr --> Na2S + 2 LiBr
2) 20.0 g Li2S x ( 1 mole Li2S/ 45.95 g Li2S ) x
( 2 mole LiBr / 1 mole Li2S ) x
( 86.845 g LiBr / 1 mole LiBr ) = 75.6 g LiBr
R = 8.314 (L x Kpa)/(# of moles x Kelvin)
At 101 kpa and a temperature of 303 K , how much volume in Liters will 250.5 grams of gaseous nitrogen dioxide occupy?
PV = nRT
250.5 grams NO2 x ( 1 mole NO2/ 46.0 g NO2) = 5.45 moles NO2
V= ((5.45 moles x ( 8.314 L x kpa/n x K) x 303 K )/ 101kpa ) = 136 Liters
In a calorimeter, the combustion of 50.5 grams of reactant causes the water temperature in the calorimeter to rise from 25.1 degrees Celsius to 99.1 degrees Celsius. If the specific heat capacity of water is 4.184 Joules / Gram x Celsius, what is the total amount of heat transferred in joules?
q= 50.5g ( 4.184 J/ g x C) x 74.0 C
q= 15600 Joules or 1.56 x 10^4 Joules
A= Ao x (1/2) ^n
- carbon-14 has a half life of 5,730 years.
If the initial sample contained 500.0 atoms of carbon-14, and the sample only has 5.0 atoms remaining, how many half lives have occurred?
A= Ao x (1/2) ^n
5= 500 x (1/2) ^n
0.01 = (1/2) ^ n
Multiply equation by log base 10
Log ( 0.01 ) = n Log ( 1/2 )
Log ( 0.01) / Log (1/2) = n
6.6 half lives
What has been your favorite fun fact that Mr. Nelson has given this year?
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