Free Printable chapter 7

1.

Which side of a chemical equation is the reactant side?

a)

Left (before the yields sign)

b)

Right (after the yields sign)

2.

Which problem is balanced?

a)

PbO₂ + 2H₂

b)

SO₂ + H₂0 --> H₂SO₄

c)

2Na + 2H₂O --> 2NaOH + H₂

3.

Balance this equation:
FeS + 2HCl -->
FeCl₂ + H₂O

a)

FeS₂+ 2HCl --> FeCl₂ + H₂O

b)

It's already balanced

c)

FeS₂+ 2HCl --> FeCl₂ + H₄O

d)

None of these

4.

Balance this equation:
MgCl₂ --> Mg₄+ Cl₂

a)

It's already balanced.

b)

4MgCl₂ --> Mg₄+ 4Cl₂

c)

4MgCl₂ --> Mg₄+ 5Cl₂

5.

Which side of a chemical equation is the reactant side?

The reactant side of a chemical equation is the left side, before the yields sign (→). This is where the starting substances, or reactants, are listed before they undergo a chemical reaction to form products.

a)

Left (before the yields sign)

b)

Right (after the yields sign)

6.

Which problem is balanced?

a)

PbO₂ + 2H₂

b)

SO₂ + H₂0 --> H₂SO₄

c)

2Na + 2H₂O --> 2NaOH + H₂

7.

Balance this equation:
FeS + 2HCl -->
FeCl₂ + H₂O

a)

FeS₂+ 2HCl --> FeCl₂ + H₂O

b)

It's already balanced

c)

FeS₂+ 2HCl --> FeCl₂ + H₄O

d)

None of these

8.

Balance this equation:
MgCl₂ --> Mg₄+ Cl₂

a)

It's already balanced.

b)

4MgCl₂ --> Mg₄+ 4Cl₂

c)

4MgCl₂ --> Mg₄+ 5Cl₂

9.

Balance this equation:
FeS + 2HCl -->
FeCl₂ + H₂O

a)

FeS₂+ 2HCl --> FeCl₂ + H₂O

b)

It's already balanced

c)

FeS₂+ 2HCl --> FeCl₂ + H₄O

d)

None of these

10.

Balance this equation:
2Li + Cl₂ -> LiCl Reasoning: To balance the chemical equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. In the given equation, we have 2 lithium (Li) atoms and 2 chlorine (Cl) atoms on the reactant side. Therefore, we need 2 LiCl molecules on the product side to balance the equation, resulting in 2Li + Cl₂ -> 2LiCl.

a)

2Li + Cl₂ -> 4LiCl2

b)

2Li + Cl₂ -> LiCl₂

c)

2Li + Cl₂ -> 2LiCl

11.

Is this equation balanced?

a)

yes

b)

no

c)

Not enough information

12.

Balance this equation.
_CH₄ + _O₂--> _CO₂+ _H₂O
Reasoning: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. For CH₄ + O₂ --> CO₂ + H₂O, we start by balancing the carbon atoms. There is 1 carbon atom in CH₄ and 1 in CO₂, so carbon is balanced. Next, we balance the hydrogen atoms. There are 4 hydrogen atoms in CH₄ and 2 in H₂O, so we need 2 H₂O molecules to balance the hydrogen (4 H atoms on each side). Finally, we balance the oxygen atoms. There are 2 O atoms in 2 H₂O and 2 in CO₂, totaling 4 O atoms needed on the reactant side, which requires 2 O₂ molecules. Thus, the balanced equation is CH₄ + 2 O₂ --> CO₂ + 2 H₂O.

a)

1,2,1,1

b)

2,1,2,1

c)

1,2,1,2

d)

0,2,0,2

13.

Balance this equation.
_CF₄+ _Br₂-- _CBr₄+ _F₂
Reasoning: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In the given equation, we have CF₄ and Br₂ on the reactant side and CBr₄ and F₂ on the product side. By choosing the coefficients 1, 2, 1, 2 respectively, we ensure that there is 1 carbon atom, 4 fluorine atoms, and 4 bromine atoms on both sides of the equation, thus balancing it.

a)

2,1,2,1

b)

1,2,2,1

c)

1,2,1,2

d)

2,2,2,2

14.

Balance this equation
_N₂+ _H₂--> _NH₃

a)

1,2,3

b)

1,3,2

c)

1,1,2

d)

2,1,1

15.

Balance this equation.
_Mg + _Cl₂--> _MgCl₂

a)

1, 2,1

b)

already balanced

c)

2,1,1

d)

1,1,2

16.

Balance this equation.
_SnO₂+_H₂-->_Sn +_H₂O Reasoning: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. Starting with SnO₂ + H₂ → Sn + H₂O, we can see that there is 1 Sn atom on both sides, so Sn is balanced. There are 2 O atoms in SnO₂ and 1 O atom in H₂O, so we need 2 H₂O molecules to balance the O atoms. This gives us 2 H₂O molecules, which means we need 2 H₂ molecules to balance the H atoms. Therefore, the balanced equation is SnO₂ + 2H₂ → Sn + 2H₂O. The correct option is 1,2,1,2.

a)

1,1,2,1

b)

1,2,1,1

c)

1,2,1,2

d)

1,2,2,1

17.

Balance this equation-
_SeCl₆+_O₂>_SeO₂+_Cl₂
Reasoning: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In this case, the balanced equation is SeCl₆ + O₂ → SeO₂ + 3Cl₂. This means that for every 1 molecule of SeCl₆, 1 molecule of O₂ is required to produce 1 molecule of SeO₂ and 3 molecules of Cl₂.

a)

1,2,1,2

b)

1,1,1,3

c)

1,2,1,1

d)

2,1,1,1

18.

Balance this equation
_Zn+_HCl-->_ZnCl₂+_H₂

Reasoning: To balance the chemical equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. In this reaction, zinc (Zn) reacts with hydrochloric acid (HCl) to produce zinc chloride (ZnCl₂) and hydrogen gas (H₂).

1. Count the number of Zn atoms: There is 1 Zn atom on both sides, so Zn is balanced.
2. Count the number of Cl atoms: There are 2 Cl atoms in ZnCl₂, so we need 2 HCl molecules to provide 2 Cl atoms. This balances the Cl atoms.
3. Count the number of H atoms: With 2 HCl molecules, there are 2 H atoms, which balances with the 2 H atoms in H₂.

Therefore, the balanced equation is: 1 Zn + 2 HCl --> 1 ZnCl₂ + 1 H₂.

a)

1,1,2,1

b)

1,1,1,2

c)

1,2,1,1

d)

2,1,1,1

19.

Balance this equation.
_N₂+_O₂->_H₂O+_HNO₃

Reasoning: To balance a chemical equation, the number of atoms of each element must be the same on both sides of the equation. In this case, balancing the given equation is not possible because the number of nitrogen, oxygen, and hydrogen atoms cannot be made equal on both sides with any integer coefficients.

a)

not possible

b)

2,2,1,2

c)

2,1,1,4

d)

2,2,1,4

20.

What is the arrow in a chemical equation...
H_{2 +}O --> H₂O

a)

Reactants

b)

Products

c)

Yields

d)

Chemical Equation

21.

Which problem is balanced?

a)

PbO₂ + 2H₂--> H₂SO₄

b)

SO₂ + H₂0 --> H₂SO₄

c)

2Na + 2H₂O --> 2NaOH + H₂

d)

2Na + 2H₂O --> 2NaOH + H

22.

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂--> 2Al₂O₃? Reasoning: In the given chemical equation, on the left side, there are 4 aluminum (Al) atoms as indicated by the coefficient 4 in front of Al. On the right side, the compound Al₂O₃ contains 2 aluminum atoms per molecule, and since there are 2 molecules of Al₂O₃, there are 2 x 2 = 4 aluminum atoms. Therefore, there are 4 aluminum atoms on each side of the equation.

a)

2

b)

6

c)

1

d)

4

23.

How many atoms of carbon (C) are in C₆H₁₂O₆?
Reasoning: The chemical formula C₆H₁₂O₆ indicates that there are 6 carbon atoms in one molecule of the compound, as represented by the subscript '6' following the 'C'.

a)

3

b)

6

c)

12

d)

24

24.

How many Sodium (Na) are in 6NaCl?

To find the number of Sodium (Na) atoms in 6NaCl, we need to understand that each molecule of NaCl contains one Sodium (Na) atom. Therefore, in 6 molecules of NaCl, there will be 6 Sodium (Na) atoms.

a)

1

b)

12

c)

6

25.

How many Aluminum are in Al₂O₃? Reasoning: The chemical formula Al₂O₃ indicates that there are 2 aluminum (Al) atoms and 3 oxygen (O) atoms in each molecule of aluminum oxide.

a)

3

b)

2

c)

5

26.

How many Hydrogen are in 4H₂O?

a)

6

b)

8

c)

2

d)

4

27.

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

a)

4Fe + 3O₂ -> 2Fe₂O₃

b)

2 Fe + 3O₂ -> Fe₂O₆

c)

4 Fe + O₆ -> 2Fe₂O₃

d)

None of the options are correctly balanced.

28.

What is the left part of a chemical equation called?
2H_{2 +}O₂ --> 2H₂O
Reasoning: In a chemical equation, the left side represents the reactants, which are the starting substances that undergo a chemical reaction to form new substances. In this equation, 2H_{2 +}O₂ are the reactants.

a)

Reactants

b)

Products

c)

Yields

d)

Chemical Equation

29.

What does the Law of Conservation of Mass state?

a)

Matter cannot be gained or lost in a chemical reaction.
Reasoning: The Law of Conservation of Mass states that in a closed system, mass is conserved over time. This means that the mass of the reactants equals the mass of the products in a chemical reaction, indicating that matter is neither created nor destroyed.

b)

Matter can only be lost in a chemical reaction.

c)

Matter can only be gained in a chemical reaction.

d)

Matter can be gained and lost in a chemical reaction.

30.

What is the right part of a chemical equation called...
2H_{2 +}O₂ --> 2H₂O

a)

Reactants

b)

Products

c)

Yields

d)

Chemical Equation

31.

What is the total number of atoms present in 5Na₃PO₄? To find the total number of atoms, first calculate the number of atoms in one formula unit of Na₃PO₄. There are 3 sodium (Na) atoms, 1 phosphorus (P) atom, and 4 oxygen (O) atoms, making a total of 3 + 1 + 4 = 8 atoms per formula unit. Since there are 5 formula units, multiply the number of atoms in one unit by 5: 8 * 5 = 40 atoms in total.

a)

5

b)

40

c)

55

d)

8

32.

What is the little number after an element in a chemical equation called.
Example: H₂

a)

Coefficient

b)

Subscript

c)

Atom

d)

Equation

33.

How many atoms of carbon (C) are in C₆H₁₂O₆?
Reasoning: The chemical formula C₆H₁₂O₆ represents a molecule of glucose, which contains 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. The subscript number after each element symbol indicates the number of atoms of that element in the molecule. Therefore, there are 6 carbon atoms in C₆H₁₂O₆.

a)

3

b)

6

c)

12

d)

24

34.

How many Sodium (Na) are in 6NaCl?
Reasoning: In the chemical formula 6NaCl, the coefficient '6' indicates that there are 6 units of NaCl. Each unit of NaCl contains 1 Sodium (Na) atom. Therefore, in 6NaCl, there are 6 Sodium (Na) atoms.

a)

1

b)

12

c)

6

35.

How many Aluminum are in Al₂O₃? Reasoning: The chemical formula Al₂O₃ indicates that there are 2 aluminum (Al) atoms and 3 oxygen (O) atoms in each molecule of aluminum oxide.

a)

3

b)

2

c)

5

36.

How many Hydrogen are in 4H₂O?

a)

6

b)

8

c)

2

d)

4

37.

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

a)

4Fe + 3O₂ -> 2Fe₂O₃

b)

2 Fe + 3O₂ -> Fe₂O₆

c)

4 Fe + O₆ -> 2Fe₂O₃

d)

None of the options are correctly balanced.

38.

What is the left part of a chemical equation called?
2H_{2 +}O₂ --> 2H₂O
Reasoning: In a chemical equation, the left side represents the reactants, which are the starting substances that undergo a chemical reaction to form new substances, known as products, on the right side.

a)

Reactants

b)

Products

c)

Yields

d)

Chemical Equation

39.

What does the Law of Conservation of Mass state?

a)

Matter cannot be gained or lost in a chemical reaction.
Reasoning: The Law of Conservation of Mass states that in a closed system, mass is conserved over time. This means that the mass of the reactants equals the mass of the products in a chemical reaction, indicating that matter is neither created nor destroyed.

b)

Matter can only be lost in a chemical reaction.

c)

Matter can only be gained in a chemical reaction.

d)

Matter can be gained and lost in a chemical reaction.

40.

What is the right part of a chemical equation called...
2H_{2 +}O₂ --> 2H₂O

The right part of a chemical equation represents the substances that are produced as a result of the reaction. These are known as the 'products'. In the given equation, 2H₂O is the product formed from the reaction of hydrogen and oxygen.

a)

Reactants

b)

Products

c)

Yields

d)

Chemical Equation

41.

What is the total number of atoms present in 5Na₃PO₄?

a)

5

b)

40

c)

55

d)

8

42.

What is the little number after an element in a chemical equation called.
Example: H₂

a)

Coefficient

b)

Subscript

c)

Atom

d)

Equation

43.

What reaction has the following general formula:

AB --> A + B

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

44.

What reaction has the following general formula:

A + CD --> C + AD

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

45.

What reaction has the following general formula:

AB + CD --> CB + AD

Reasoning: In this reaction, the ions of two compounds exchange places to form two new compounds. This type of reaction is known as a double replacement reaction, where the cations and anions of the reactants switch places to form new products.

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

46.

What reaction has the following general formula:

A + B --> AB

Reasoning: In a combination reaction, two or more substances (A and B) combine to form a single product (AB). This is the general form of a combination reaction.

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

47.

What reaction has the following general formula:
$C_xH_y\ +\ O_2\ ->CO_{2\ }+\ H_2O$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

48.

What is the general reaction scheme for a single replacement reaction?

a)

A + B --> AB

b)

AB --> A + B

c)

A + CD --> C + AD

d)

AB + CD --> CB + AD

e)

$C_xH_y+O_2\ ->\ CO_2+H_2O$

49.

What is the general reaction scheme for a combustion reaction?

a)

A + B --> AB

b)

AB --> A + B

c)

A + CD --> C + AD

d)

AB + CD --> CB + AD

e)

$C_xH_y+O_2\ ->\ CO_2+H_2O$ - This represents a combustion reaction where a hydrocarbon (C_xH_y) reacts with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O).

50.

What is the general reaction scheme for a combination reaction?

a)

A + B --> AB

b)

AB --> A + B

c)

A + CD --> C + AD

d)

AB + CD --> CB + AD

e)

$C_xH_y+O_2\ ->\ CO_2+H_2O$

51.

What is the general reaction scheme for a double replacement reaction?

a)

A + B --> AB

b)

AB --> A + B

c)

A + CD --> C + AD

d)

AB + CD --> CB + AD

e)

$C_xH_y+O_2\ ->\ CO_2+H_2O$

52.

What is the general reaction scheme for a decomposition reaction?

a)

A + B --> AB

b)

AB --> A + B

c)

A + CD --> C + AD

d)

AB + CD --> CB + AD

e)

$C_xH_y+O_2\ ->\ CO_2+H_2O$

53.

What type of reaction is the following:
$2H_2+O_2->2H_2O$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

54.

What type of reaction is the following:
$BaCl_2+2KI\ ->\ 2KCl\ +\ BaI_2$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

55.

What type of reaction is the following:
$C_{11}H_{24}+17O_2->\ 11CO_2\ +\ 12H_2O$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

56.

What type of reaction is the following:
$2KI\ ->\ 2K\ +\ I_2$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

57.

What type of reaction is the following:
$2NaHCO_3->\ Na_2CO_3+CO_2+H_2O$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

58.

What type of reaction is the following:
$Zn\ +\ 2HCl\ ->\ ZnCl_2+H_2$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

59.

What type of reaction is the following:
$3CuS\ +2Al\ ->\ Al_2S_3+3Cu$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

60.

What type of reaction is the following:
$2C_4H_{10}\ +13O_2\ ->\ 8CO_2+10H_2O$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

61.

What type of reaction is the following:
$Na_2S\ +2HCl\ ->\ H_2S+2NaCl$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

62.

What type of reaction is the following:
$Ag_3N\ +\ 3HBr->3AgBr+H_3N$

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

chapter 7

Total questions: 62

Worksheet time: 2hrs 30mins

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