Unit 6 - Chemical Reactions

Question 1

What is the 3 in 2Na₃PO₄?

Answer 1

a subscript (showing the amount of atoms in Na)

Question 2

How many atoms of sodium are in 2Na₃PO₄?

Answer 2

6 (2x3)

Question 3

What are signs of a chemical reaction?

Answer 3

gas formation, precipitate formation, color change, temperature change

Question 4

When Sn⁴⁺ becomes Sn²⁺ , is this reduction or oxidation?

Answer 4

reduction (oil rig, reduction is gain of electrons)

Question 5

The term used to describe a chemical reaction in which a substance loses electrons to another substance is

Answer 5

oxidation (oil rig, oxidation is loss of electrons)

Question 6

Acid-base reactions are what type of reaction?

Answer 6

double displacement

Question 7

The equation A + X → AX is the general equation for what type of reaction?

Answer 7

synthesis

Question 8

An element in the activity series can replace any element

Answer 8

below it on the list

Question 9

In the equation, Cu + AgNO₃

—> Ag + Cu(NO₃)₂, silver has been replaced by ______.

Answer 9

copper

Question 10

The equation AX + BY → AY + BX is the general equation for:

Answer 10

double displacement

Question 11

If a compound could be a precipitate in an aqueous solution is in soluble or insoluble?

Answer 11

insoluble

Question 12

In a double displacement reaction, calcium hydroxide and hydrogen chloride react to produce calcium chloride. What is the other product?

Answer 12

water

Question 13

In what type of reaction does one element replace a similar element in a compound?

Answer 13

single displacement

Question 14

According to the law of conservation of mass, the total mass of the reacting substances is

Answer 14

Always equal to the total mass of the products

Question 15

To balance a chemical equation, it may be necessary to adjust the

Answer 15

coefficients

Question 16

In an equation, the symbol for a substance dissolved in water is followed by

Answer 16

(aq) aqueous

Question 17

In writing an equation that produces oxygen gas, the correct representation of oxygen gas is:

Answer 17

O₂ (it is part of the BrINClHOF twins)

Question 18

Breaking of magnesium oxide into magnesium and oxygen is an example of

Answer 18

decomposition

Question 19

What type of reaction is Zn + 2HCl —> ZnCl₂ + H₂?

Answer 19

single displacement

Question 20

What type of reaction is FeS

—> Fe + S?

Answer 20

decomposition

Question 21

What type of reaction is CH₄ + O₂ —> CO₂ + 2H₂O?

Answer 21

combustion

Question 22

What type of reaction is NaCl + H₂SO₄ —> Na₂SO₄ + HCl?

Answer 22

double displacement

Question 23

What type of reactions is 2K + Cl₂ —>2 KCl

Answer 23

synthesis

Question 24

The reactants in this reaction

KCl (aq) + AgNO3 (aq) → KNO3 (aq) + AgCl (s) are

Answer 24

potassium chloride and silver nitrate

Question 25

When lead reacts with iron (II) sulfate in a single displacement reaction, what would the products be?

Answer 25

no reaction, (iron is higher than lead on the activity series)

Question 26

How many oxygen atoms are in 4 molecules of glucose (C₆H₁₂O₆)?

Answer 26

24 (4x6)

Question 27

What are the products of a combustion reaction?

Answer 27

carbon dioxide and water

Question 28

A double replacement reaction that has a product with a precipitate will have the symbols:

Answer 28

one product (aq), one product (s)

Question 29

When balancing equations the atoms must

Answer 29

equal on both sides