Question 1

Which of the following is NOT an indication that a chemical reaction has occurred?

Accepted Answer

Change in temperature without any other observable change

Question 2

What is the correct balanced chemical equation for the reaction of hydrogen and oxygen to form water?

Accepted Answer

$$2H_2(g) + O_2$(g) \rightarrow 2H_2O(l)$$

Question 3

Which symbol in a chemical equation indicates that a substance is dissolved in water?

Accepted Answer

$$(aq)$$

Question 4

What is the general form of a synthesis reaction?

Accepted Answer

$$A + X \rightarrow AX$$

Question 5

Which of the following elements normally exists as a diatomic molecule at room temperature?

Accepted Answer

Oxygen

Question 6

A student mixes solutions of lead(II) nitrate and potassium iodide. A yellow solid forms. What type of reaction has occurred?

Accepted Answer

Double-displacement reaction

Question 7

Which of the following equations is correctly balanced?

Accepted Answer

$$2Al(s) + 3Cl_2(g) \rightarrow 2AlCl_3(s)$$

Question 8

In the reaction $$2KClO_3(s) \rightarrow 2KCl(s) + 3O_2(g)$$, what type of reaction is taking place?

Accepted Answer

Decomposition reaction

Question 9

Which of the following best describes the role of a catalyst in a chemical reaction?

Accepted Answer

It increases the rate of reaction without being consumed.

Question 10

Given the reaction $$Zn(s) + 2HCl(aq) \rightarrow $$ZnCl_2$$(aq) + H_2$(g)$$, what is the evidence that a chemical reaction has occurred?

Accepted Answer

Formation of a gas

Question 11

Which of the following reactions is a combustion reaction?

Accepted Answer

$$CH_4(g) + 2O_2(g$$) \rightarrow $$CO_2(g) + 2H_2O(g$$)$$

Question 12

What is the correct product for the reaction $$Mg(s) + 2HCl(aq)$$?

Accepted Answer

$$MgCl_2(aq$$) + $$H_2(g$$)$$

Question 13

Which of the following is the correct word equation for the reaction $$2Al(s) + 3CuSO_4(aq) \rightarrow Al_2$(SO_4$)_3(aq) + 3Cu(s)$$?

Accepted Answer

Aluminum reacts with copper(II) sulfate to produce aluminum sulfate and copper.

Question 14

Which of the following is a single-displacement reaction?

Accepted Answer

$$Fe(s) + $$CuSO_4$$(aq) \rightarrow $$FeSO_4$$(aq) + Cu(s)$$

Question 15

If 4 moles of $$H_2$$ react with excess $$O_2$$, how many moles of $$H_2O$$ are produced according to the equation $$2H_2 + O_2$ \rightarrow 2H_2O$$?

Accepted Answer

4 moles

Question 16

Which of the following best describes the activity series of the elements?

Accepted Answer

A list of elements organized by their ability to undergo chemical reactions

Question 17

What is the product of the decomposition of calcium carbonate when heated?

Accepted Answer

$$CaO(s) + CO_2$(g)$$

Question 18

Which of the following reactions will NOT occur based on the activity series?

Accepted Answer

$$Cu(s) + HCl(aq) \rightarrow no $$reaction

Question 19

A student observes the reaction $$AgNO_3(aq) + $$NaCl(aq) \rightarrow AgCl(s) + $$NaNO_3(aq$$)$$. What evidence supports that a chemical reaction has occurred?

Accepted Answer

Formation of a precipitate

Chemical Equations and Reactions: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard