During digestion, the energy in food is converted to energy the body can use. Scientists use calorimetry experiments to measure the calories, or energy, provided by food when it is digested or burned. 

The relationship used to find the heat transferred energy  is given by , where  is the mass of the material,  is the given specific heat capacity, and  is the change in temperature of the material. 

In this experiment, food was burned over a Bunsen burner under a can of 200 ml of water. The temperature change of the water and mass change of the food can be used to determine the calories in four different food items.

Table 1 shows the values of the change of mass of the food items, the change in temperature of the water and the energy. Table 2 shows the energy to mass ratio of three of those food items.

                                                    Table 1

                                  Roasted Peanut  Peanut    Cracker    Cheese Puff

Water Temp. Initial         23.9 °C           33.2 °C     40.3 °C      53.9 °C

Water Temp. Final           30.0 °C           40.9 °C     55.9 °C      62.8 °C

Food Mass Initial             0.69 g             0.61 g       3.21 g        1.22 g

Food Mass Final               0.38 g             0.21 g       0.91 g        0.48 g

Energy                            1.22 Cal          1.54 Cal     3.12 Cal     1.78 Cal

                           Table 2

Sample         Energy to Mass Ratio (Cal/g)

     1                                 1.36

     2                                 3.93

     3                                 2.40

The student performing the experiment concluded that eating an amount of crackers would provide an athlete with more energy than eating the same amount of any of the other food samples. Do the results in Tables 1 and 2 support this claim?

A student wished to study the acidity and basicity of various household ingredients and chemicals using her own, homemade pH indicator. A pH indicator is a substance that changes colors to indicate the acidity or basicity of a chemical solution. Acids can be defined as substances that donate hydrogen ions, or H⁺, while bases are substances that accept H­⁺ ions. The strength of these acids and bases can be measured using the pH scale as shown in Figure 1.

Experiment 1:

The student placed a leaf of red cabbage in a blender with one liter of water and blended until the cabbage had been liquefied. She then strained the purple mixture and bottled it. The student then added one drop of her homemade cabbage pH indicator to a variety of household chemicals listed in Table 1. She recorded the known pH of these chemicals as well as the color the indicator turned when added to these chemicals.

Experiment 2:

The student wanted to see how baking soda would react in the presence of other household chemicals. She combined baking soda in water separately with each of the other chemicals used in Experiment 1. Some combinations would create bubbling while some other combinations wouldn't. She recorded the results in Table 2 below.

If four solutions were made from household chemicals and the red cabbage indicator and resulted in the four following colors, which solution contained the most acidic chemical?

A student wished to study the acidity and basicity of various household ingredients and chemicals using her own, homemade pH indicator. A pH indicator is a substance that changes colors to indicate the acidity or basicity of a chemical solution. Acids can be defined as substances that donate hydrogen ions, or H⁺, while bases are substances that accept H­⁺ ions. The strength of these acids and bases can be measured using the pH scale as shown in Figure 1.

Experiment 1:

The student placed a leaf of red cabbage in a blender with one liter of water and blended until the cabbage had been liquefied. She then strained the purple mixture and bottled it. The student then added one drop of her homemade cabbage pH indicator to a variety of household chemicals listed in Table 1. She recorded the known pH of these chemicals as well as the color the indicator turned when added to these chemicals.

Experiment 2:

The student wanted to see how baking soda would react in the presence of other household chemicals. She combined baking soda in water separately with each of the other chemicals used in Experiment 1. Some combinations would create bubbling while some other combinations wouldn't. She recorded the results in Table 2 below.

Which of the following answer choices lists the four acids lemon juice, vinegar, toilet bowl cleaner, and soda pop in order from weakest to strongest?

A student wished to study the acidity and basicity of various household ingredients and chemicals using her own, homemade pH indicator. A pH indicator is a substance that changes colors to indicate the acidity or basicity of a chemical solution. Acids can be defined as substances that donate hydrogen ions, or H⁺, while bases are substances that accept H­⁺ ions. The strength of these acids and bases can be measured using the pH scale as shown in Figure 1.

Experiment 1:

The student placed a leaf of red cabbage in a blender with one liter of water and blended until the cabbage had been liquefied. She then strained the purple mixture and bottled it. The student then added one drop of her homemade cabbage pH indicator to a variety of household chemicals listed in Table 1. She recorded the known pH of these chemicals as well as the color the indicator turned when added to these chemicals.

Experiment 2:

The student wanted to see how baking soda would react in the presence of other household chemicals. She combined baking soda in water separately with each of the other chemicals used in Experiment 1. Some combinations would create bubbling while some other combinations wouldn't. She recorded the results in Table 2 below.

The student will attempt to color in Figure 1 with the appropriate color the indicator will turn at various pHs. Which answer choice lists the colors in the correct order, from left, or low pHs, to right, or high pHs?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

At  and  (atmospheres of pressure), in what state of matter is Compound ?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

Which answer choice ranks the Compounds A-C in order of increasing triple point temperatures?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

What processes must occur at temperatures and pressures along the green curve in these figures?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

The process of a gas being converted to a solid is called "deposition." For what range of temperatures in degrees Kelvin () could deposition of Compound A occur for pressures between 5 and 10 atmospheres (atm)?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

The slope of the blue line depends on the relative densities of the solid and the liquid. A positive slope means that the solid is denser than the liquid; a negative slope means the opposite. Which compounds have solid phases that are denser than their liquid phases?

Phase diagrams show what state of matter (solid, liquid, or gas) a chemical compound is in for a given temperature and pressure. Compounds , , and  have the following phase diagrams shown in Figure 1.

The triple point is the temperature and pressure at which a compound exists simultaneously in all three states of matter and is found on the phase diagram where the three curves intersect.

In a room with a pressure of 10 atmospheres (atm) at  (Kelvin), solid Compound C is placed on a table. Then, the temperature is slowly increased up to . Which of the following answer choices list the states of matter Compound C will take as the temperature increases?