Interactive Chemistry Worksheets for Students

 

Periodic table

Naming compounds

Basic formula

Simple compounds

Ionic compounds 1

Ionic compounds 2

Chemical suffixes

Old chemical names

Hydrocarbons - Alkanes

Alkanes, alkenes & alkynes

Alkanols to alkanoic acids

 

Common compounds

Common formula quiz

Acids, bases and salts

Covalent compounds

Printable worksheets
 

 

 

Student Instructions for balancing equations

  1. Identify the reactants and products and write a word equation.
  2. Write the correct chemical formula for each of the reactants and the products.
  3. Check to see whether there are the same NUMBERS and TYPES of atoms on both sides of the equation. i.e. The Law of Conservation of Matter.
  4. Balance each chemical equation by placing whole numbers in front of the chemical formula.

eg. The burning of steel wool(iron) in air.

Step 1.             Iron + Oxygen → Iron(II) oxide
Step 2 & 3       Fe + O2  → FeO                     
Step 4          2Fe + O2 → 2FeO

 

Chemical formula help

Acids Alkalis (Bases)

Acetic acid, CH3COOH, produces acetate salts, CH3COO-

Hydrochloric acid, HCl, produces chloride salts, Cl-

Nitric acid, HNO3, produces nitrate salts, NO3-

Sulfuric acid, H2SO4, produces sulfate salts, SO42-

Ammonia NH3

Potassium hydroxide, KOH

Sodium hydroxide, NaOH

 

Cations (positive ions) Anions (negative ions)
aluminum Al3+, ammonium NH4+ , barium Ba2+, calcium Ca2+, copper Cu2+, iron(II) Fe2+, iron(III) Fe3+, lead Pb2+,  lithium Li+, magnesium Mg2+, mercury Hg2+, sodium Na+, potassium K+, silver Ag+, zinc Zn2+ bromide Br-, carbonate CO32-, chloride Cl-, hydroxide OH-, nitrate NO3-, phosphate PO43- and sulfate SO42-

 

Diatomic molecules: Bromine Br2, chlorine Cl2, hydrogen H2, nitrogen N2 and oxygen O2

 

Chemical Valencies or Combining Powers of Elements

Element 1 2 3

Metal

Lithium Li, potassium K, sodium Na

Silver Ag

Barium Ba, calcium Ca, magnesium Mg

Copper Cu, iron(II) Fe, mercury Hg, zinc Zn

Lead Pb

Aluminium Al

Iron(III) Fe
 

Non-metal

Hydrogen H

Bromine Br, chlorine Cl

Oxygen O, sulfur S

Nitrogen N

 

 

Write balanced equations for the following reactions

1. Magnesium ribbon burns in air to produce a white powder. A synthesis reaction.

2. Aluminum reacts with oxygen to produce a compound.

3. Hydrochloric acid and magnesium react to produce hydrogen gas and a magnesium salt

4. Sulfuric acid and zinc react to produce hydrogen gas and a zinc salt.

5. The action of sulfuric acid on calcium carbonate produces water, a calcium salt and a gas that turns limewater milky.

6. The heating of mercury(II) oxide, HgO, causes it to decompose into its elements. This is an example of a decomposition reaction.

7. The heating of copper carbonate produces carbon dioxide gas and copper oxide.

8. Copper oxide reacts with hydrochloric acid to produce a green solution of copper(II) chloride and water.

9. A strip of copper metal when placed in a solution of silver nitrate produces metallic silver and a copper salt.

10. When a solution of silver nitrate comes into contact with a solution of sodium chloride a white precipitate of silver chloride and a solution of sodium nitrate are produced.

11. Potassium hydroxide can be used to neutralise a solution of hydrochloric acid. It produces a potassium salt and water.

12. Sodium hydroxide can be used to neutralise a solution of sulfuric acid. It produces a salt plus water.

13. Chlorine gas and potassium bromide react to produce potassium chloride and bromine.

14. Aluminum and bromine combine violently to produce a single compound.

15. Sodium reacts violently with water to produce a solution of sodium hydroxide and hydrogen gas.

16. Iron(III) oxide when heated in hydrogen produces iron and water.

17. Limewater (calcium hydroxide) reacts with carbon dioxide to produce water and a precipitate of calcium carbonate.

18. Limestone (calcium carbonate) when strongly heated decomposes into carbon dioxide and quicklime (calcium oxide).

19. Copper oxide and carbon when heated together produce the copper metal and carbon monoxide gas.

20. Hydrochloric acid and sodium sulfide produce hydrogen sulfide gas and a salt.

21. Copper sulfate and sodium hydroxide when mixed together produce a precipitate of copper hydroxide and a solution of sodium sulfate.

22. Copper hydroxide when heated produces black copper oxide and steam(H2O).

23. Copper oxide when heated in the presence of hydrogen gas produces copper metal and water.

24. Sodium hydroxide reacts with a solution of ammonium chloride to produce ammonia gas, salt and water.

25. A mixture of sodium iodide and lead nitrate produces a solution of sodium nitrate and a precipitate.

26. The complete combustion of methane (CH4) produces carbon dioxide and water.  Note: In a combustion reaction a fuel reacts with oxygen.

27. The combustion of ethanol, (C2H5OH) produces carbon dioxide and water

28. The combustion of glucose, (C6H12O6) produces carbon dioxide and water

29. Barium hydroxide reacts with sulfuric acid to produce a white precipitate and water

30. A solution of mercury(II) nitrate reacts with a solution of potassium iodide to produce a bright orange mercury(II) iodide precipitate and a solution of potassium nitrate.

31. In the process of fermentation, yeast breakdown glucose molecules (C6H12O6) to produce ethanol(C2H5OH) and carbon dioxide gas.

32. In the process of photosynthesis, plants use carbon dioxide and water to make glucose(C6H12O6) and oxygen.

33. A solution of silver nitrate reacts with a solution of potassium phosphate to produces a yellow precipitate of silver phosphate and a solution of potassium nitrate.

34. Sodium hydrogen carbonate, NaHCO3 and acetic acid react to produce carbon dioxide, water and sodium acetate, CH3COONa

35. In the Haber process nitrogen and hydrogen combine to produce ammonia

36. In the Solvay process calcium carbonate and sodium chloride are used to produce calcium chloride and sodium carbonate via an indirect pathway.

37. Brown nitrogen dioxide gas(NO2) combines with water to produce a mixture of nitric acid and nitrous acid (HNO2).

38. Sodium oxide dissolves in water to produce a strong alkali solution

39. Lithium hydroxide is used in space missions to remove carbon dioxide from the air. Lithium carbonate and water are produced.

40. Colourless nitrogen monoxide(NO) combines with oxygen to produce brown nitrogen dioxide(NO2).

 

Balancing Chemical Equations Answers

1. Magnesium + oxygen → magnesium oxide

2Mg + O2 → 2MgO

2. Aluminum + oxygen → aluminum oxide

4Al + 3O2 → 2Al2O3

3. Hydrochloric acid + magnesium → magnesium chloride + hydrogen

2HCl + Mg → MgCl2 + H2

4. Sulfuric acid + zinc → zinc sulfate + hydrogen

H2SO4 + Zn → ZnSO4 + H2

5. Sulfuric acid + calcium → calcium sulfate + water + carbon dioxide

H2SO4 + Ca → CaSO4 + H2O + CO2

6. Mercury(II) oxide → mercury + oxygen

2HgO → Hg + O2

7. Carbon carbonate → copper oxide + carbon dioxide

CuCO3 → CuO + CO2

8. Copper oxide + hydrochloric acid → copper(II) chloride + water

CuO + 2HCl → CuCl2 + H2O

9. Copper + silver nitrate → copper(II) nitrate + silver

Cu + 2AgNO3 → Cu(NO3)2 + 2Ag

10. Silver nitrate + sodium chloride → silver chloride + sodium nitrate

AgNO3 + NaCl → AgCl(s) + NaNO3 where (s) = solid or precipitate

11. Potassium hydroxide + hydrochloric acid → potassium chloride + water

KOH + HCl → KCl + H2O

12. Sodium hydroxide + sulfuric acid → sodium sulfate + water

2NaOH + H2SO4 → Na2SO4 + 2H2O

13. Chlorine + potassium bromide → potassium chloride + bromine

Cl2 + 2KBr →2KCl + Br2

14. Aluminum + bromine → aluminum bromide

2Al + 3Br2 → 2AlBr3

15. Sodium + water → sodium hydroxide + hydrogen

2Na + 2H2O → 2NaOH + H2

16. Iron(III) oxide + hydrogen → iron + water

Fe2O3 + 3H2 → 2Fe +3H2O

17. Calcium hydroxide + carbon dioxide → water + calcium carbonate

Ca(OH)2 + CO2 → H2O + CaCO3

18. Calcium carbonate → calcium oxide + carbon dioxide

CaCO3→ CaO + CO2

19. Copper oxide + carbon → copper + carbon monoxide

CuO + C → Cu + CO

20. Hydrochloric acid + sodium sulfide → hydrogen sulfide + sodium chloride

2HCl + Na2S → H2S + 2NaCl

21. Copper sulfate + sodium hydroxide → copper hydroxide + sodium sulfate

CuSO4 + 2NaOH → Cu(OH)2(s) + Na2SO4

22. Calcium hydroxide → copper oxide + water

Cu(OH)2→ CuO + H2O

23. Copper oxide + hydrogen → copper + water

CuO + H2 → Cu + H2O

24. Sodium hydroxide + ammonium chloride → sodium chloride + ammonia + water

NaOH + NH4Cl → NaCl + NH3 + H2O

25. Sodium iodide + lead nitrate

2NaI + Pb(NO3)2 → 2NaNO3 + PbI2(s)

26. Methane + oxygen → carbon dioxide + water

CH4 + 2O2→ CO2 + 2H2O

27. Ethanol + oxygen → carbon dioxide + water

C2H5OH + 3O2→ 2CO2 + 3H2O

28. Glucose + oxygen → carbon dioxide + water

C6H12O6 + 6O2→ 6CO2 + 6H2O

29. Barium hydroxide + sulfuric acid → barium sulfate + water

Ba(OH)2 + H2SO4 → BaSO4 + H2O

30. Mercury(II) nitrate + potassium iodide → mercury iodide + potassium nitrate

Hg(NO3)2 + 2KI →HgI2(s) + 2KNO3

31. Glucose → ethanol + carbon dioxide

C6H12O6 → 2C2H5OH + 2CO2

32. Carbon dioxide + water → glucose + oxygen

6CO2 + 6H2O → C6H12O6 + 6O2

33. Silver nitrate + potassium phosphate → silver phosphate + potassium nitrate

3AgNO3 + K3PO4 → Ag3PO4 + 3KNO3

34. Sodium hydrogen carbonate + acetic acid → sodium acetate + carbon dioxide + water

NaHCO3 + CH3COOH →CH3COONa + CO2 + H2O

35. Nitrogen + hydrogen → ammonia

N2 + 3H2 →2NH3

36. Calcium carbonate + sodium chloride → sodium carbonate + calcium chloride

CaCO3 + 2NaCl → Na2CO3 + CaCl2

37. Nitrogen dioxide + water → nitric acid + nitrous acid

NO2 + 2H2O → HNO3 + HNO2

38. Sodium oxide + water → sodium hydroxide

Na2O + H2O → 2NaOH

39. Lithium hydroxide + carbon dioxide → lithium carbonate + water

2LiOH + CO2 → Li2CO3 + H2O

40. Nitrogen monoxide + oxygen → nitrogen dioxide

2NO + O2 → 2NO2

 

Chemistry worksheets withs answers - PDF Downloads

Balancing Chemical equations - US Spellling

Balancing Chemical equations - International Spellling

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