Q: A sample of water is heated from $$25\ ^\circ \mathrm{C} to$$ $$75\ ^\circ \mathrm{C}. If $$the mass of water is $$50\ \mathrm{g}$$ and the specific heat of water is $$4.18\ \mathrm{J}/\mathrm{g}\cdot\ ^\circ \mathrm{C}$$, how much heat is absorbed?

$$Q = m \times c \times \Delta T = 50 \times 4.18 \times (75 - 25) = 10,450\ \mathrm{J}$$

Q: Which of the following is a correct conversion for $$1\ \mathrm{cm}^3$$?

$$1\ \mathrm{cm}^3 = 1\ \mathrm{mL} = 1\ \mathrm{cc} = 20\ \text{drops}$$

Q: A compound contains $$2.0\ \mathrm{mol} of $$sodium chloride ($$\mathrm{NaCl}). $$How many formula units are present?

$$2.0 \times 6.022 \times 10$$^{23}$$ = 1.204 \times 10$$^{24}$$ formula units

Q: What is the molar mass of sodium sulfate ($$\mathrm{Na_2SO_4}$$)?

$$2 \times 22.99 + 32.07 + 4 \times 16.00 = 142.05\ \mathrm{g/mol}$$

Question 1

Which of the following best describes the difference between accuracy and precision in a laboratory measurement?

Accepted Answer

Accuracy refers to how close a measurement is to the true value, while precision refers to how close repeated measurements are to each other.

Question 2

A patient’s urine sample has a specific gravity (SG) of 1.030. Which of the following best describes what this indicates about the patient’s hydration status?

Accepted Answer

The patient is likely dehydrated, as the urine is more concentrated.

Question 3

Which of the following is an example of a chemical change?

Accepted Answer

Burning wood in a fireplace

Question 4

A sample of water is heated from $$25\ ^\circ \mathrm{C} to$$ $$75\ ^\circ \mathrm{C}. If $$the mass of water is $$50\ \mathrm{g}$$ and the specific heat of water is $$4.18\ \mathrm{J}/\mathrm{g}\cdot\ ^\circ \mathrm{C}$$, how much heat is absorbed?

Accepted Answer

$$Q = m 	imes c 	imes \Delta T = 50 	imes 4.18 	imes (75 - 25) = 10,450\ \mathrm{J}$$

Question 5

Which of the following statements about isotopes is TRUE?

Accepted Answer

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

Question 6

Which of the following is a correct conversion for $$1\ \mathrm{cm}^3$$?

Accepted Answer

$$1\ \mathrm{cm}^3 = 1\ \mathrm{mL} = 1\ \mathrm{cc} = 20\ 	ext{drops}$$

Question 7

Which element is a noble gas and is located in Group 8A of the periodic table?

Accepted Answer

Neon ($$\mathrm{Ne})$$

Question 8

A compound contains $$2.0\ \mathrm{mol} of $$sodium chloride ($$\mathrm{NaCl}). $$How many formula units are present?

Accepted Answer

$$2.0 	imes 6.022 	imes 10$$^{23}$$ = 1.204 	imes 10$$^{24}$$ formula units

Question 9

Which of the following best describes the bond in a water molecule ($$\mathrm{H}_2\mathrm{O}$$)?

Accepted Answer

Polar covalent bond

Question 10

Which of the following is the correct formula for the compound formed between calcium and nitrate?

Accepted Answer

$$\mathrm{Ca(NO_3$)_2}$$

Question 11

Which of the following is a heterogeneous mixture?

Accepted Answer

Salad with lettuce, tomatoes, and cucumbers

Question 12

What is the molar mass of sodium sulfate ($$\mathrm{Na_2SO_4}$$)?

Accepted Answer

$$2 	imes 22.99 + 32.07 + 4 	imes 16.00 = 142.05\ \mathrm{g/mol}$$

Question 13

Which of the following is a correct electron arrangement for magnesium ($$\mathrm{Mg}$$, atomic number 12)?

Accepted Answer

$$2, 8, 2$$

Question 14

Which of the following is the correct formula for the polyatomic ion sulfate?

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 15

Which of the following reactions is a combustion reaction?

Accepted Answer

$$\mathrm{CH_4$} + 2\mathrm{O_2$} \rightarrow \mathrm{CO_2$} + 2\mathrm{H_2O}$$

Question 16

Which of the following statements about the periodic table is TRUE?

Accepted Answer

Elements in the same group have similar chemical properties.

Question 17

Which of the following is the correct balanced equation for the decomposition of water?

Accepted Answer

$$2\mathrm{H_2O} \rightarrow 2\mathrm{H_2$} + \mathrm{O_2$}$$

Question 18

Which of the following is an example of an endothermic reaction?

Accepted Answer

Photosynthesis in plants

Question 19

Which of the following best describes the trend in atomic size across a period from left to right?

Accepted Answer

Atomic size decreases

Exam 1 Study Guide: Chemistry Fundamentals (Chapters 1, 2, 3, 4, 6, 7)

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