Chem. Rev. Chapter 5 Chemical reaction

Chem. Rev. Chapter 5 Chemical reaction

By Michelle Zou

Multiple Choice

What is the left part of a chemical equation called?

2H₂ + O₂ ---> 2H₂O

• Reactants

• Yields

• Products

• Chemical equation

Multiple Choice

What is the right part of a chemical equation called?

2H₂ + O₂ ---> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

Multiple Choice

The Law of Conservation of Mass states Matter is NEITHER created nor destroyed.

• True

• False

TRUE!

The Law states matter is neither created nor destroyed as seen in this image. We started with 100g and when we broke apart the elements they STILL equal 100g of mass.

Multiple Choice

If a reaction starts with a total 75g of reactants it should produce 

• a total of 40g of products
• a total of 75g of products
• a total of 180 g of products
• None of the above

Multiple Choice

24 g of magnesium reacts with 38 g of fluorine to produce _____ g magnesium fluoride

• 62 
• 38
• 24
• 14

Multiple Choice

Which equation best represents the law of conservation of mass? 

• A
• B
• C
• D

What is a molecule?

Multiple Choice

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms
• Same subscripts
• Same coefficients

LET'S TAKE IT STEP BY STEP AND PRACTICE

Multiple Choice

How many elements does PbNO₃ have?

• 2
• 3
• 4
• 5

Multiple Choice

How many oxygen atoms are in this chemical formula?

• 6 oxygen atoms

• 2 oxygen atoms

• 3 oxygen atoms

• 4 oxygen atoms

Multiple Choice

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

Multiple Choice

Which of the following has the most molecules of O?

• 2Mg₃(PO₄)₂

• 4AlPO₄

• 3Al(NO₃)₃

• 15KOH

Multiple Choice

Which of the following equations are correctly balanced?

• 12CO₂ + H₂O ---> C₆H₁₂O₆ + O₂

• CO₂ + H₂O ---> 3C₆H₁₂O₆ + O₂

• CO₂ + 9H₂O ---> C₆H₁₂O₆ + O₂

• 6CO₂ + 6H₂O ---> C₆H₁₂O₆ + 6O₂

Multiple Choice

Balance this equation:

HgO ---> 2Hg + O₂

• It is balanced.

• 2HgO ---> 2Hg + O₂

• 2HgO ---> Hg + O₂

• HgO ---> Hg + 2O₂

Multiple Choice

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

Multiple Choice

Balance the following equation:

___ H₂+ ___ O₂→___ H₂O

• 1, 1, 3

• 2, 2, 2

• 1, 2, 1

• 2,1, 2

Multiple Choice

Balance the following equation:

__CO + __Fe₂O₃--> __Fe + __CO₂

• 3,1 --> 2,3

• 3,2 --> 1,1

• 3,2 --> 2,4

• 3,2 --> 2,1

Multiple Choice

Balance the following equation:

__Al + __O₂--> __Al₂O₃

• 4,1 --> 2

• 4,3 --> 4

• 3,4 --> 1

• 4,3 --> 2

Multiple Choice

Which equation supports this model?

• 2H₂ + O₂ → 2H₂O

• H₂ + O₂ → 2H₂O

• 2H₂O₂ → 2H₂O

• 2H₂ + O₂ → H₂O

​Relative Formula Mass

A measure (still not the exact mass) of a molecule, using the relative atomic mass on the Periodic Table. ​

​Sometimes called relative molecular mass, molar mass etc. All using the same procedure.

Multiple Choice

Name this compound:

CO

• Carbon Oxide

• Carbon Oxygen

• Dicarbon dioxide

• Carbon Monoxide

Multiple Choice

Calculate the relative formula mass for Al(OH)₃

• 78.0

• 72

• 28

• 25

Multiple Choice

What is the relative formula mass of CO₂?

• 12
• 16
• 32
• 44

Multiple Choice

What is the relative atomic mass of sodium?

• 11
• 23
• 46
• 64

Multiple Choice

What is the unit of relative formula mass?

• kilogram
• gram
• gram per mole (g/mol)
• no units

Multiple Choice

The formula of a compound is M(OH)₂. Given that the M_r of the compound is 98, calculate the A_r of M.

• 32
• 64
• 81
• 94

Multiple Choice

What is the general formula for the computation of percentage composition of the given element?

• % mass of element = mass of element in the compound divided by mass of the compound times 100

• % mass of element = mass of element in the compound divided by mass of the compound

• % mass of element = mass of element in the compound divided by 100

• % mass of element = mass of element in the compound

Multiple Choice

What is the percent by mass of magnesium in MgO?

• 20%

• 40%

• 50%

• 60%

Multiple Choice

What is the percent by mass of chlorine in NaCl?

• 39%

• 61%

• 35%

• 35%

Fill in the Blank

4g of KMnO4 is heated to decompose. Calculate the mass of oxygen gas produced.

Multiple Choice

In a chemical reaction, 4 grams of sodium must combine with how many grams of chlorine to produce 10 grams of table salt?

• 4 grams

• 6 grams

• 8 grams

• 10 grams

Multiple Choice

2Na + 2H₂O → 2NaOH+ H₂

How many grams of hydrogen are produced if 120 g of Na are available?

• 5.27 g

• 2.6 g

• 690 g

• 45 g

Multiple Choice

2H₂   +   O₂  →  2H₂O How many grams of water can be produced if 8 gram of O₂ are used?

• 4.5 g

• 9 g

• 18 g

• 8 g

Well done MBSer!