Question 1

Which of the following is NOT an observable evidence of a chemical reaction taking place?

Accepted Answer

Change in mass

Question 2

What happens on a molecular level when a chemical reaction occurs?

Accepted Answer

Bonds are broken and new bonds are formed

Question 3

Which symbol in a chemical equation represents a substance in the gaseous state?

Accepted Answer

$$(g)$$

Question 4

Given the chemical equation $$2\mathrm{$$NaHCO_3$$}(s) \rightarrow \mathrm{Na_2CO_3}(s) + \mathrm{H_2O}(l) + \mathrm{CO_2$}(g)$$, which product is released as a gas?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 5

Which of the following best describes a chemical reaction?

Accepted Answer

Atoms are rearranged and new chemical bonds are formed in the products

Question 6

In the reaction $$2\mathrm{$$NaHCO_3$$}(s) \rightarrow \mathrm{Na_2CO_3}(s) + \mathrm{H_2O}(l) + \mathrm{CO_2$}(g)$$, what does the symbol $$(s)$$ indicate?

Accepted Answer

The substance is a solid

Question 7

Which of the following is a correct chemical equation for the decomposition of sodium bicarbonate?

Accepted Answer

$$2\mathrm{$$NaHCO_3$$}(s) \rightarrow \mathrm{Na_2CO_3}(s) + \mathrm{H_2O}(l) + \mathrm{CO_2$}(g)$$

Question 8

Which of the following changes is NOT evidence of a chemical reaction?

Accepted Answer

Change in shape

Question 9

When sodium bicarbonate is heated, which of the following is a product that is a liquid?

Accepted Answer

$$\mathrm{H_2O}$$

Question 10

Which of the following is a correct statement about chemical equations?

Accepted Answer

They use chemical formulas and symbols to represent chemical reactions

Question 11

A student observes a reaction where a solid forms from two clear solutions. What is this evidence of?

Accepted Answer

Formation of a precipitate

Question 12

Which of the following is a plausible misconception about chemical reactions?

Accepted Answer

Atoms are destroyed during the reaction

Question 13

If a chemical reaction results in a temperature increase, what type of reaction is most likely occurring?

Accepted Answer

Exothermic

Question 14

Which of the following is the correct symbol for an aqueous solution in a chemical equation?

Accepted Answer

$$(aq)$$

Question 15

A chemical reaction is observed to produce bubbles in a liquid. What does this indicate?

Accepted Answer

Formation of a gas

Chemical Reactions: Evidence, Equations, and Symbols

Guida di studio - Domande di pratica

Study guide - Flashcard