Question 1

Which of the following statements correctly describes what changes when an atom becomes an ion?

Accepted Answer

The number of electrons changes, resulting in a charged species.

Question 2

A student is given a sample of a clear, colorless liquid. After evaporation, no residue remains. Which classification best describes the sample?

Accepted Answer

Compound

Question 3

Which of the following is a chemical change?

Accepted Answer

Silver tarnishing

Question 4

Round $$0.000584763 to $$four significant figures and write the result in standard scientific notation.

Accepted Answer

$$5.847 	imes 10$$^{-4}$$

Question 5

How many significant figures are in $$0.0008060$$?

Accepted Answer

4

Question 6

A student measures a known $$10.00-mL $$sample four times and obtains $$9.51$$, $$9.50$$, $$9.52$$, and $$9.51 mL. $$Which statement best describes the results?

Accepted Answer

The results are precise but not accurate.

Question 7

Perform the following calculation and report the answer with the correct significant figures: $$(12.36 	imes 0.42) + 6.8$$

Accepted Answer

$$12.0$$

Question 8

Convert $$22.5\ ^\circ\mathrm{C} to $$Kelvin.

Accepted Answer

$$295.7\ \mathrm{K}$$

Question 9

A metal sample has a mass of $$54.6\ \mathrm{g}$$ and a volume of $$7.00\ \mathrm{cm}^3. $$What is its density?

Accepted Answer

$$7.80\ \mathrm{g/cm}^3$$

Question 10

Convert $$4.75$$ miles to kilometers. ($$1$$ mile $$= 1.609 km)$$

Accepted Answer

$$7.64\ \mathrm{km}$$

Question 11

A liquid has a density of $$0.825\ \mathrm{g/mL}. $$What is the mass, in kilograms, of $$12.5\ \mathrm{L} of $$the liquid?

Accepted Answer

$$10.3\ \mathrm{kg}$$

Question 12

Which pair of elements would most likely form an ionic compound?

Accepted Answer

Mg and Cl

Question 13

Calculate the molar mass of acetaminophen, $$\mathrm{C}_8\mathrm{H}_9\mathrm{NO}_2.$$

Accepted Answer

$$151.16\ \mathrm{g/mol}$$

Question 14

How many molecules are present in $$0.425$$ mol $$\mathrm{CO}_2$$?

Accepted Answer

$$2.56 	imes 10$$^{24}$$

Question 15

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$\mathrm{H}_2\mathrm{O}$$. How many moles of $$\mathrm{H}_2\mathrm{O}$$ are present?

Accepted Answer

$$0.500$$ mol

Question 16

Calculate the mass percent of oxygen in $$\mathrm{H}_2\mathrm{O}.$$

Accepted Answer

$$88.8\%$$

Question 17

A compound contains $$52.2\% C$$, $$13.0\% H$$, and $$34.8\% O by $$mass. What is its empirical formula?

Accepted Answer

$$\mathrm{C}_2\mathrm{H}_6\mathrm{O}$$

Question 18

An element has two naturally occurring isotopes: $$62.930$$ amu ($$69.17\%) $$and $$64.928$$ amu ($$30.83\%). $$What is the average atomic mass?

Accepted Answer

$$63.55$$ amu

Question 19

What is the correct chemical formula for cobalt(II) nitrate hexahydrate?

Accepted Answer

$$\mathrm{Co(NO}_3)_2 \cdot 6\mathrm{H}_2\mathrm{O}$$

Question 20

What is the systematic name for $$\mathrm{CuCl}_2$$?

Accepted Answer

Copper(II) chloride

General Chemistry Exam 1 Review: Step-by-Step Study Guidance

Guida di studio - Domande di pratica

Study guide - Flashcard