Question 1

Which of the following statements best explains why electromagnetic radiation with a shorter wavelength has higher energy?

Accepted Answer

Because frequency increases as wavelength decreases, and energy is proportional to frequency: $$E = h 
u$$

Question 2

A sample contains $$7.31 	imes 10$$^{15}$$ molecules of NO_2$. How many moles of NO_2$ are present?

Accepted Answer

$$1.21 	imes 10$$^{-8}$$ mol

Question 3

Which element has the highest ionization energy among the following?

Accepted Answer

chlorine

Question 4

What is the electron configuration for an atom of cobalt ($$Co) $$using noble gas notation?

Accepted Answer

$$[Ar] 3d^7$ 4s^2$

Question 5

Calculate the mass, in grams, of a $$1.53$$ mole sample of lithium ($$Li$$). ($$Li$$ atomic mass = $$6.94 g/$$mol)

Accepted Answer

$$10.6 g$$

Question 6

Which of the following is a reactant in the chemical reaction: $$Zn (s) + 2HCl (aq) \rightarrow H_2$ (g) + $$ZnCl_2$$ (aq)$$?

Accepted Answer

hydrochloric acid

Question 7

A compound has a molar mass of $$60.0 g/$$mol and an empirical formula of $$CH_2O. $$What is the molecular formula?

Accepted Answer

$$C_2H_4O_2$$

Question 8

Determine the number of moles of carbon present in a $$0.345$$ mole sample of acetic acid, $$HC_2H_3O_2.$$

Accepted Answer

$$0.690$$ mol C

Question 9

Which of the following best describes oxidation in a chemical reaction?

Accepted Answer

A loss of electrons

Question 10

What is the total number of electrons possible in a $$3p$$ subshell?

Accepted Answer

6

Question 11

Calculate the molar mass of $$Ba(NO_3$)_2.$$

Accepted Answer

$$261.3 g/$$mol

Question 12

Which of the following is the correct order of coefficients required to balance the equation: $$AgNO_3$$ + $$FeCl_3$$ \rightarrow Fe($$NO_3)_3 + $$AgCl$$?

Accepted Answer

3, 1, 1, 3

Question 13

Which of the following best describes the physical state of potassium in the reaction: $$K(s) + H_2O(l) \rightarrow H_2$(g)$$?

Accepted Answer

solid

Question 14

A quantum packet of energy that has both particle and wave properties is called:

Accepted Answer

a photon

Question 15

Determine the percentage composition, by mass, of nitrogen in $$N_2O.$$

Accepted Answer

$$63.65\% N$$

Question 16

Which of the following elements is most likely to form a $$2+$$ cation?

Accepted Answer

calcium

Question 17

Classify the following reaction: $$HNO_3(aq) + $$NaOH(aq) \rightarrow H_2O(l) + $$NaNO_3(aq$$)$$

Accepted Answer

neutralization

Question 18

How many orbitals are there in the $$n = 4$$ principal shell?

Accepted Answer

16

Question 19

Consider the following: $$Fe^{3+}(aq) + e$$^- \rightarrow $$Fe^{2+}(aq$$)$$. The reaction above represents:

Accepted Answer

reduction

Question 20

Which of the following is the correct value for Avogadro's number?

Accepted Answer

$$6.022 	imes 10$$^{23}$$

Introduction to Chemistry: Key Concepts and Practice Questions

Guida di studio - Domande di pratica

Study guide - Flashcard