Q: A nutrition label states that a serving of food contains 9 g of fat, 4 g of protein, and 12 g of carbohydrate. Calculate the total energy content in Calories (Cal) for this serving. (Fat: 9 Cal/g, Protein: 4 Cal/g, Carbohydrate: 4 Cal/g)

$$9 \times 9 + 4 \times 4 + 12 \times 4 = 81 + 16 + 48 = 145\ \text{Cal}$$

Q: A beaker contains 250.0 mL of water at $$25^\circ\text{C}. If $$the specific heat of water is $$4.18\ \text{J/g}^\circ\text{C}$$ and the density of water is $$1.00\ \text{g/mL}$$, how much energy (in J) is required to raise the temperature to $$75^\circ\text{C}$$?

$$250.0 \times 1.00 \times 4.18 \times (75 - 25) = 52,250\ \text{J}$$

Q: Which of the following is the correct conversion factor to convert inches to centimeters?

$$1\ \text{in} = 2.54\ \text{cm}$$

Q: Which of the following best describes a physical property?

Water boils at $$100^\circ\text{C}.$$

Question 1

Which of the following statements best describes a scientific theory?

Accepted Answer

A well-tested explanation for a broad set of observations.

Question 2

A student measures the mass of a sample three times and records the values: 2.51 g, 2.53 g, and 2.52 g. The true mass is 2.80 g. Which statement best describes the accuracy and precision of these measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 4

Which of the following changes is a chemical change?

Accepted Answer

Burning wood

Question 5

A patient’s urine has a specific gravity of 1.030. What does this value indicate?

Accepted Answer

The urine is more dense than water.

Question 6

Which of the following is the correct nuclear notation for an isotope of carbon with 7 neutrons?

Accepted Answer

$$^{13}_{6}	ext{C}$$

Question 7

How many significant figures are in the measurement 0.00450 mL?

Accepted Answer

3

Question 8

Which of the following elements is a metalloid?

Accepted Answer

Silicon (Si)

Question 9

A sample of metal has a mass of 45.0 g and a volume of 15.0 mL. What is its density?

Accepted Answer

$$3.00\ 	ext{g/mL}$$

Question 10

Which group on the periodic table is known as the alkali metals?

Accepted Answer

Group 1A

Question 11

Which of the following statements about Dalton’s atomic theory is NOT correct according to modern understanding?

Accepted Answer

Atoms of the same element are identical in mass and properties.

Question 12

A nutrition label states that a serving of food contains 9 g of fat, 4 g of protein, and 12 g of carbohydrate. Calculate the total energy content in Calories (Cal) for this serving. (Fat: 9 Cal/g, Protein: 4 Cal/g, Carbohydrate: 4 Cal/g)

Accepted Answer

$$9 	imes 9 + 4 	imes 4 + 12 	imes 4 = 81 + 16 + 48 = 145\ 	ext{Cal}$$

Question 13

Which of the following best describes the trend in atomic size as you move down a group in the periodic table?

Accepted Answer

Atomic size increases.

Question 14

A beaker contains 250.0 mL of water at $$25^\circ	ext{C}. If $$the specific heat of water is $$4.18\ 	ext{J/g}^\circ	ext{C}$$ and the density of water is $$1.00\ 	ext{g/mL}$$, how much energy (in J) is required to raise the temperature to $$75^\circ	ext{C}$$?

Accepted Answer

$$250.0 	imes 1.00 	imes 4.18 	imes (75 - 25) = 52,250\ 	ext{J}$$

Question 15

Which of the following is the correct electron arrangement for a neutral atom of magnesium (Mg, atomic number 12)?

Accepted Answer

2, 8, 2

Question 16

Which of the following is an example of potential energy?

Accepted Answer

A stretched rubber band

Question 17

How many protons, neutrons, and electrons are in the isotope $$^{31}_{15}	ext{P}$$?

Accepted Answer

15 protons, 16 neutrons, 15 electrons

Question 18

Which of the following is the correct conversion factor to convert inches to centimeters?

Accepted Answer

$$1\ 	ext{in} = 2.54\ 	ext{cm}$$

Question 19

Which of the following best describes a physical property?

Accepted Answer

Water boils at $$100^\circ	ext{C}.$$

Question 20

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

CHEM 1300 Exam 1 Study Guide: Chemistry in Our Lives, Measurements, Matter, and Atoms

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