Question 1

Which of the following is an example of an intensive physical property?

Accepted Answer

Density

Question 2

A student mixes two clear aqueous solutions and observes the formation of a solid. Which type of chemical reaction has most likely occurred?

Accepted Answer

Double replacement (precipitation) reaction

Question 3

Which of the following best describes the Law of Conservation of Mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 4

Which of the following is a chemical property?

Accepted Answer

Flammability

Question 5

Consider the reaction: $$2H_2(g) + O_2$(g) \rightarrow 2H_2O(l). $$Which statement is true?

Accepted Answer

The number of oxygen atoms is the same on both sides of the equation.

Question 6

Which of the following changes is a chemical change?

Accepted Answer

Burning wood

Question 7

A student heats a sample of copper(II) carbonate ($$CuCO_3) $$and observes the formation of copper(II) oxide ($$CuO) $$and carbon dioxide gas ($$CO_2). $$What type of reaction is this?

Accepted Answer

Decomposition

Question 8

Which of the following best represents a combustion reaction?

Accepted Answer

$$C_3H_8(g) + 5O_2(g) \rightarrow 3CO_2(g) + 4H_2O(g)$$

Question 9

Which of the following is the correct net ionic equation for the reaction between aqueous solutions of $$Pb(NO_3$)_2$$ and $$NaCl$$?

Accepted Answer

$$Pb^{2+}(aq) + 2Cl^-(aq$$) \rightarrow $$PbCl_2(s$$)$$

Question 10

Which of the following statements about balancing chemical equations is correct?

Accepted Answer

You may only change the coefficients in front of compounds or elements.

Question 11

A student observes that a piece of magnesium metal reacts vigorously with hydrochloric acid, producing bubbles of gas. Which gas is produced in this reaction?

Accepted Answer

Hydrogen

Question 12

Which of the following is a correct example of a single replacement reaction?

Accepted Answer

$$Zn(s) + $$CuSO_4$$(aq) \rightarrow $$ZnSO_4$$(aq) + Cu(s)$$

Question 13

Which of the following best describes a physical change?

Accepted Answer

Water freezing to form ice

Question 14

A solution of sodium sulfate ($$Na_2SO_4) is $$mixed with a solution of barium chloride ($$BaCl_2). $$What is the precipitate formed?

Accepted Answer

$$BaSO_4$$

Question 15

Which of the following is the correct balanced equation for the combustion of methane ($$CH_4$$)?

Accepted Answer

$$CH_4 + 2O_2$$ \rightarrow $$CO_2 + 2H_2O$

Question 16

Which of the following is NOT an indicator of a chemical change?

Accepted Answer

Change in state from solid to liquid

Question 17

A student adds silver nitrate ($$AgNO_3) to a $$solution of sodium chloride ($$NaCl) $$and observes a white solid forming. What is the net ionic equation for this reaction?

Accepted Answer

$$Ag^+(aq) + Cl^-(aq) \rightarrow AgCl(s)$$

Question 18

Which of the following best describes the difference between a physical and a chemical property?

Accepted Answer

A physical property can be observed without changing the identity of the substance.

Question 19

Which of the following reactions is a decomposition reaction?

Accepted Answer

$$2KClO_3(s) \rightarrow 2KCl(s) + 3O_2(g)$$

Question 20

A student mixes ethanol and dry sand and observes bubbles forming. What does the formation of bubbles most likely indicate?

Accepted Answer

A chemical change is occurring

Chemical Reactions: Properties, Changes, and Equations

Guida di studio - Domande di pratica

Study guide - Flashcard