Molarity
The formula for molarity is
What is molarity = mole/Liter
What is the main heat equation?
q = mc(ΔT)
ΔT = change in temperature, q = heat. m= mass, c = specific heat capacity
Which pigment in leaves give the green color in leaves?
What is chlorophyll?
Which piece of laboratory apparatus stores the titrant?
What is the buret (or burette)?
In the PhET simulation, we compared the specific heat capacities of oil, water, iron, and brick. Which had the highest specific heat capacity?
What is water?
It's tough to surpass the heat capacity of water. It requires a lot of heat to even increase the temperature of water by even a small amount.
If we dissolve 0.2 mole of solute in enough water to make 400 mL of solution, the molarity is
What is 0.5 mole/L
Molarity=mole/L; L=400 mL÷1000=0.4 L
Molarity=0.2 mole/0.4 L=0.5 mole/L
What are the units of specific heat capacity?
What is J/gC
Specific heat capacity: (heat in J)÷(m×ΔT)
m has units of g, ΔT has units of C
ΔT = final temperature - initial temperature
Which color of visible light is best absorbed by the chlorophyll?
What is red light?
Which piece of glassware is typically used to draw up an accurate and precise volume of the titrand?
What is the pipette?
Of all the substances analyzed in the PhET simulation (oil, water, iron, and brick), which substance was the best conductor?
What is brick?
Brick had the lowest specific heat capacity. The lower the specific heat capacity, the greater the conductivity.
If we dissolve 54 g of glucose (molar mass 180 g/mole) in enough solvent to make 1200 mL solution, find the molarity.
What is 0.25 mole/L
Mole glucose: 54 g/(180 g/mol)=0.3 mole
L solution: 1200 mL÷1000=1.2 L
Molarity=0.3 mole/1.2 L=0.25 M
Find the heat in J required to raise the temperature of water (specific heat capacity = 4.18 J/gC) from 20 to 22 C. The mass of the water sample is 50 g.
What is 836 J
q=mcΔT=50g×4.18 J/gC×(22 C - 20 C)
q=836 J
What are the two main segments of photosynthesis?
What is the
a.Light reaction
b.Calvin cycle
In the titration of HCl with NaOH, name the indicator used.
What is phenolphthalein?
In the photosynthesis simulation, the production of the molecule ___ helped us monitor the progress of photosynthesis.
What is O2?
Remember the overall reaction:
6CO2+6H2O+ light enervy=C6H12O6+6O2
O2 is on the product side and because it is a gas, it is visible
Is molarity an intensive or extensive property?
What is intensive? Although moles depends on mass, so does the volume. Remember, molarity equals mole/L...if two extensive properties are divided, the resulting property is intensive.
If 1254 J of heat is transferred to 100 g of water (specific heat capacity=4.18 J/gC) initially at 20 C, find the final temperature of the water.
What is 23 C?
1254 J=100 g(4.18 J/gC)(T - 20 C)
1254 =418(T-20)
3 = T - 20
T = 23 C
Why does it make sense that red light is absorbed well by water during the light reaction?
Water tends to scatter blue light...meaning that it is more likely that red light is absorbed
An indicator changes color at the ______point.
What is neutralization?
Did light intensity affect the rate of photosynthesis? Why?
Yes, up to a certain point. The greater the intensity of light, the greater the amount of photons. It is the photon which strikes the chlorophyll molecule in a leaf, starting a bunch of reactions in the light reaction phase.
If we want to make 250 mL of 0.1 M glucose (molar mass = 180 g/mol), how many g of glucose is needed?
What is 4.5 g.; L=250 mL÷1000=0.250 L
Mole= 0.1 mole/L×0.25 L=0.025 mole
Grams= 0.025 mole×180 g/mole= 4.5 g
Mole= molarity×liters
Gram= mole×molar mass
Given the data: Higher T of water: 22 C
Mass metal: 50 g Higher T of metal: 100 C
Mass water: 100 g Lower T of water: 20 C
Specific heat capacity of water: 4.18 J/gC
Find the metal specific heat capacity
What is 0.21 J/gC
Heat metal transferred:4.18J/gC(100g)(22-20C)
temperature change of metal: 100C-22C=78 C
Mass metal: 50 g
Specific heat capacity: 836 J/(50g×78C)
Think about the visible light color chlorophyll absorbs. What does this suggest about the strength of the chemical bonds in chlorophyll?
What are weaker bonds?
Red light has a longer wavelength. Light energy is inversely proportional to wavelength. Lower energy stored in bonds result in a weaker bond.
Given an initial buret reading of 12.17 mL and a final buret reading of 27.17 mL, if the molarity of NaOH inside the buret is 0.10 M, and if the volume of HCl is 25.00 mL, find the molarity of HCl.
What is 0.06 M
Volume NaOH: (27.17-12.17 mL)÷1000=0.015 L
Mole NaOH=0.10M×0.015L=0.0015 mole
= mole HCl; V for HCl: 25 mL÷1000=0.025 L
Molarity HCl:0.0015mole/0.025L=0.06M
This is a sneaky question. If we turned off the lights after photosynthesis had been going on for a while, what would we observe for the glucose level if we had a glucometer?
For a while, the glucose level would not change, but then start dropping.
Why?There will still be reserves of the high energy molecules used in the Calvin cycle. Glucose is produced in the Calvin cycle. However, the light reaction will be impacted, eventually impacting the Calvin cycle.