Odds and Ends
Heat Capacity
Scientific Method
Heat (the other stuff)
Labs
Chemical Reactions
100
A favorite breakfast food is pancakes. This simplified recipe calls for 2 cups of pancake mix, 1 cup of milk, 2 eggs, and 1 teaspoon of vanilla.
If I have 6 cups of mix, 3 cups of milk, 5 eggs, and 8 teaspoons of vanilla. What is the limiting ingredient (or reactant)?
Eggs
100
The amount of heat required to change its temperature.
What is the heat capacity?
100
The claim that a "detox" tea can "flush toxins" from your liver and kidneys without naming specific toxins or mechanisms is often cited as pseudoscientific because:
It uses vague, "sciency" sounding terms that lack precise biological definitions.
100
What are the three primary methods of heat transfer?
The three primary methods of heat transfer are conduction , convection , and radiation
100
Professor Lyons drops her phone (mass = 200 g, volume = 50 cm³) in a tank of milk (density = 1.03 g/cm³). Does it sink or float?
Sinks (density = 4 g/cm³ > 1.03 g/cm³).
100
What type of chemical reaction is this?
C3H8 + O2 --> 3CO2 + 4H2O
What is a combustion reaction?
200
Where is the boiling point?
4
200
Two objects made of different materials but with the same mass are heated with the same amount of energy. If one object experiences a larger temperature change than the other, what can you conclude about their specific heat capacities?
You can conclude that the object with the larger temperature change has a lower specific heat capacity.
200
A study with 20 individuals examined whether the perception of sweet or sour changed when consumed at different temperatures. The temperatures were 3 °C, 22 °C, and 60 °C. Sweetness was perceived as more intense at 60°C than at 23°C and 3°C. Sourness was perceived as more intense at 23°C compared to 3°C and 60°C.
What is the independent variable?
What is the dependent variable?
IV: Different temperatures
DV: Perception of sweet or sour
200
What is thermal radiation, and how does it differ from conduction and convection?
Thermal radiation is the transfer of heat through electromagnetic waves (usually infrared radiation). It differs from conduction and convection because it doesn't require a medium for heat transfer and can occur through a vacuum, such as in the case of the Sun's heat reaching Earth.
200
In the heat-of-fusion experiment, you were told to collect the ice in a paper towel (not a beaker, etc)
Why?
You were told to use a paper towel because it serves two critical lab functions that a beaker or watch glass cannot achieve: blotting away surface water, so only ice is added
200
What are the five types of reactions?
Synthesis, Decomposition, Combustion, Single Replacement, Double Replacement
300
The Georgetown Mantra of bioethics is a framework of four core moral principles for evaluating ethical decisions in medicine and healthcare.
What is one of the four core moral principles?
If you can explain your choice, you won't get extra points, but I will be impressed.
Beneficience
Non-malfeisance
Autonomy
Justice
300
Calculate the specific heat capacity of copper with a mass of 75 g and a temperature difference of 10 °C if 200 J of heat is lost.
Mass m = 75 g, Temperature difference T = 10oC, Heat lost Δ Q = 200 J c = qmΔT = 200J/ (75g×10oC) = 0.267 J/goC.
300
In this graph, which are the independent and dependent variables?
IV) The solutions of ethanol
DV) Absorbance
300
Type of reaction where heat is transferred from the system to the surroundings.
What is exothermic?
300
To determine the freshness of eggs, we measured the mass and volume of three different eggs.
Which of these eggs is the freshest? Order them from freshest to least fresh.
Egg A Egg B Egg C
Mass (g) 66.2 62.5 59
Volume (mL) 59 49 61
B --> A--> C
A) 1.12
B) 1.28
C) 0.97
300
What is the definition of polar covalent bonds
When electrons are not shared equally between atoms, usually because of the difference in electronegativity.
Causes a positive and negative charge on the compound
400
If a pepperoni Hot Pocket contained 15 g of fat, 35 g of carbohydrates, and 9 g of protein. How many calories would that be?
15 g x 9 Cal =135 Cal
35 g x 4 Cal =140 Cal
9 g x 4 Cal = 36 Cal
311 Cal
400
A 50.0 g block of glass (Cp = 0.50 J/goC) absorbs 333 joules of heat energy. How much does the glass temperature rise?
q = cmΔT T= q/cm T= (333J)/ (0.50 J/goC x 50g) T= 13.32 oC
400
Identify the control group. How does honey impact the growth of bacteria on a culture?
What is the bacteria culture without honey?
400
When you open your freezer, what heat transfer occurs with you and the freezer?
When you open a freezer, heat transfers from you into the freezer because heat always moves from a warmer object to a colder one
400
The Law of Conservation of Energy states that energy is neither created nor destroyed. However, in this lab, the heat the water gains is almost always much lower than the heat released by the burning Cheetos.
Where exactly does the "missing" energy go
Most of the 'missing' energy went into the environment.
This was not a closed system?
400
Ionic bonds form between two…
What is oppositely charged ions?
500
Food irradiation kills 99% of potentially harmful foodborne organisms.
What are the three sources of ionizing energy?
Electron beam, gamma ray and X-ray
500
You drink 600 grams of cold water at 10 °C. How much energy is needed to warm this water to body temperature (37 °C)?
If 1 kCal (Nutritional calorie) - 4184 Joules. How many Calories did you burn in heating the cold water to body temperature?
q = mCn(Tf-Ti)
q =(600 g)(4.18 J/gC)(27oC)
q = 67,716 J
Number of calories is 67,716/4184 = 16 Calories
By the way, to burn a pound you need to expend 3500 Calories - so don't think drinking cold water is a diet plan!!!
500
Create a null and alternative hypothesis for an experiment testing whether incorporating rosemary extract into plastic packaging film reduces the average bacterial count,
Null: Incorporating rosemary does not reduce bacterial count
Alternative: Incorporating rosemary does reduce bacterial count
500
How do the boiling and freezing points of a water sample change when you dissolve salt in it?
What is the eutectic point?
The boiling point increases and the freezing point decreases.
The eutectic point is the lowest freezing point.
500
In two labs, we looked at calorimetry. In the popcorn lab, “A Trip to the Movies, we did a calorimetry experiment with different popcorn preparations.
What was the independent variable?
What was the dependent variable?
What is one standardized variable?
IV) Types of popcorn
DV) Joules/g
Standardized) Method
500
Which correctly represents hydrogen bonds?
A