Chem 1010 Chapter 10 Smart Book

A banana can be eaten off of a tree or cooked in dishes. What is the purpose of cooking the banana?

To transform its taste

In the sous vide method of cooking, food is cooked under ______ and at a temperature _______ the temperature at which it is to be served.

vacuum; the same as

A liquid can evaporate at any temperature, producing vapor above the surface of the liquid. This vapor exerts a pressure, which is called ________ the pressure. This pressure ________ as the temperature of the liquid increases. When this pressure equals the external pressure, the liquid has reached its boiling point.

vapor; increases

What is the partial pressure of O2 in the air around us if the molar concentration of O2 in a sample of river water is 14 mg/L and the kH for O2 in H2O is equal to 1.3 x 10-3 mol/L⋅atm? Round your answer to two decimal places.

0.34

Density is defined as mass per volume. If 1 cup of butter is equivalent to 226 g of butter, and 1 cup is equivalent to 250 mL, what is the density of butter in g/mL?

0.90 g/mL

The partial pressure of O2 in the air around us is 0.21 atm. What is the molar concentration of O2 in a sample of river water at normal atmospheric pressure if the value of kH for O2 in H2O is equal to 1.3 x 10-3 mol/L⋅atm?

2.7 x 10-4 mol/L C = 1.3 x 10-3 mol/L⋅atm x 0.21 atm = 2.7 x 10-4 mol/L

A cookie recipe calls for 1/2 cup of butter, 1 cup of sugar, 2 eggs, and 1 1/4 cups of flour for 2 dozen cookies. You need to make 150 cookies for a bake sale. How much of each ingredient do you need? Select all that apply.

6 1/4 cups of sugar 3 1/8 cups of butter

A cookie recipe calls for 1/2 cup of butter, 1 cup of sugar, 2 eggs, and 1 1/4 cups of flour for 2 dozen cookies. You have 1 1/2 cups of butter, 21212 cups sugar, 6 eggs, and 4 cups of flour. How many cookies can you bake?

60 cookies

The back of the tongue: The sides of the tongue: The center of the tongue: The front of the tongue:

Bitter Sour Not Many receptors Salty/sweet

Given the mass to volume conversions for various food items in the table below, rank them in order of increasing density (mass per volume), starting with the least dense food at the bottom of the list. Assume that 1 cup is equivalent to 250 mL.

Butter Brown Sugar Chocolate Chips Cake Flour

Henry's Law expresses the relationship between the concentration of a gas in solution and the pressure on the solution. Which of the following options correctly describe the quantities in the Henry's Law equation, given below?Henry's Law: C = kP

C is the concentration of the gas in moles per liter. P is the pressure measured in atmospheres. k is called the Henry's Law constant for a particular gas/solvent combination.

Why do bubbles rush out of a carbonated beverage when the container is opened? Multiple choice question.

CO2 becomes less soluble in the beverage when the pressure is released.

In the process of fermentation ______. (Select all that apply.)

CO2 is produced a micro-organism such as yeast is required glucose and other sugars are converted to ethanol

Which of the following include reasons to transform our food in some way? Select all that apply.

Cooking food may kill dangerous organisms. Transformation of food may improve the taste.

In cooking, thermometers are most typically used for _______. (Select all that apply.)

Ensuring the oven is at the correct temperature determining the internal temperature of the meat Measuring the temperature of a sugar mixture when making candy

In the sous vide method of cooking _______. (Select all that apply.)

Food is cooked at the same temperature at which it is to be eaten The food to be cooked is vacuum sealed

The intermolecular attractions between water molecules are relatively strong, so that water requires a significant input of energy to overcome these attractions and change phase. Water is said to have a high _____ heat.

Latent

Which of the following correctly describe steps in the processing of coffee? Select all that apply.

More flavor is extracted from finely ground coffee beans. Roasting of coffee beans improves the flavor of coffee.

When food is salted for preserving ________. (Select all that apply.)

NO formed from nitrites and nitrates binds to the iron in hemoglobin NaCl added to the food causes water to be removed Nitrites and nitrates are antioxidants and kill bacteria

_____ receptors bind with the aromatic compounds found in food.

Odor

Which of the other senses plays a major role in recognition of taste?

Smell

Experts agree that the human tongue detects six basic tastes, which include ______. (Select all that apply.)

Sweet, Salty, Sour, and Fatty

The boiling point of a liquid is the temperature at which ______.

The vapor pressure of the liquid equals the external pressure.

Tuiwa, Tibet is one of the tallest places on Earth and Death Valley, California is one of the lowest places on Earth. Which statement best describes which location would require longer cooking times and why?

Tuiwa, Tibet would require longer cooking times because the boiling point is lower.

Water has a high latent heat. This means that ___________.

Water can absorb a lot of heat before changing phase

The relationship between pressure and temperature is _____.

a directly proportional relationship

A foam may be produced by _______. (Select all that apply.)

beating air into a solution with a spoon or beater injecting a gas into a thickened liquid at higher pressure

The alcoholic mixture produced by fermentation of sugars can be distilled, a process that separates liquids based on their ______. This allows ethanol to be separated from water, resulting in a solution with a ______ alcoholic content.

boiling points; higher

A refractometer _______. (Select all that apply.)

can be used to determine specific gravity detects the bending of light in a solution is often used to determine the sugar content of a solution

Which of the following are qualitative methods of determining food readiness? Select all that apply.

checking the degree of browning when frying an egg the "fist test" for grilled meat the "soft ball" test for candy

During the distillation process, the distillate is cooled in the _______ to form a liquid that can be collected.

condenser

The condenser in the distillation process _______.

cools the distillate, causing it to condense so that it can be collected as a liquid

Ethanol has a polar -OH group allowing it to dissolve readily in water and a small hydrocarbon portion, which allows it to interact with nonpolar solvents and cell membranes. We describe ethanol as having _______.

dual polarity

Mayonnaise is an example of a(n) _____, in which a nonpolar substance is dispersed in a polar solvent. This normally incompatible system is stabilized by the _____ in the mayonnaise.

emulsion; egg yolk

The process in which yeast converts sugars to alcohol and CO2 is called ________.

fermentation

When room-temperature pasta is placed in boiling water, heat flows _________, causing the pasta to cook.

from the water to the pasta

A foam is formed when a ______ is trapped in a ______.

gas; liquid or solid

Drying and curing are suitable methods of food preservation because ______.

harmful microbes also rely on water to survive

Compared to UV, IR, and visible radiation, microwave radiation ______. (Select all that apply.)

has lower energy causes molecules to rotate rather than breaking bonds

When a carbonated beverage is sealed, the pressure on the beverage is _____ than atmospheric pressure. When the can is opened, the pressure on the liquid _______ and the dissolved CO2 bubbles out as its solubility decreases.

higher; decreases

Food cooks when heated because the spontaneous flow of heat is always from an object at _____ temperature to an object at ______ temperature.

higher; lower

A _______ is an instrument that measures changes in the density of a liquid.

hydrometer

Henry's Law states that the amount of gas dissolved in a given volume of solution will ______ when the pressure increases.

increase

During a phase change such as liquid → gas for a molecular substance, the temperature of the system _______.

is unchanged

The alcoholic solution produced by fermentation can be distilled by heating in a still. The compounds with ______ boiling points evaporate first and so the distillate contains a ______ concentration of ethanol than the liquid left behind.

lower; greater

A liquid boils when its vapor pressure equals the external pressure. At higher altitudes the atmospheric pressure is lower and the liquid therefore boils at a ______ temperature. Food may therefore take _______ to cook at higher altitudes.

lower; longer

Microwave radiation has a ______ energy than UV, IR, or visible radiation and will therefore ______ in the molecules in food during cooking.

lower; not break bonds

A hydrometer, which measures changes in liquid density, would most typically be used for _______.

monitoring a fermentation process in beer or wine making

Which of the following substances may be used in the salting or salt-curing of foods? Select all that apply.

nitrite salts nitrate salts NaCl

Oil does not readily mix with water because oil is ______, while water is _______. Multiple choice question.

nonpolar; polar

The statement "like dissolves in like" means that ______.

polar substances will dissolve most readily in polar solvents

During the phase change of a molecular substance the temperature of the system is constant because heat transferred is used to change the ______ energy of the molecules by breaking or forming intermolecular attractions. Since there is no change in ______ energy of the molecules during this process, the temperature does not change.

potential; Kinetic

When determining food readiness, methods such as dropping cooked sugar mixture into cold water to determine its cooking stage are ______ methods, whereas the use of a thermometer to measure temperature is a _______ method.

qualitative; quantitative

A refractometer measures the extent to which a solution refracts (changes the direction of) light, which is expressed by its _____. This quantity _____ as the specific gravity of the solution increases.

refractive index; increases

Drying and curing preserve foods by _______.

removing water and adding salt

A thermometer would be most helpful or necessary when preparing _______. (Select all that apply.)

roasted meat candy fried chicken

The flavor components in both tea and coffee are extracted on the basis of their _______

solubility in water

A pressure cooker allows food to cook faster because ______.

the boiling point of water is higher under higher pressure

Ethanol, like other alcohols, has dual polarity because ______. (Select all that apply.)

the carbon portion of the molecule can interact with nonpolar substances the polar -OH group can interact with H2O and other polar substances

Mayonnaise is an example of an emulsion, which ______. (Select all that apply.)

would settle out unless stabilized has a nonpolar substance dispersed in a polar substance