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Practice sets, with the answers on the second page.

249 questions across the three boards: write the formula from the name, then balance the equation. Every one is drawn from what that board's own textbooks set, and every answer is checked by this site's build. Pick your board and print the section.

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ICSE · Classes 6 to 9

Indian Certificate of Secondary Education, set by the Council for the Indian School Certificate Examinations

0 formulas to write and 0 equations to balance, compiled from this board's own textbooks. The full chapter-by-chapter list is on its syllabus page.

Answers — ICSE

Mark the set against these after it is finished, not during. If you are printing the sheet and want the answers on it, leave this block open before you print — it starts a new page.

CBSE · Classes 7 to 10

Central Board of Secondary Education

79 formulas to write and 67 equations to balance, compiled from this board's own textbooks. The full chapter-by-chapter list is on its syllabus page.

Write the formula

Write the chemical formula for each. Where a metal has two states, the state is given — without it the question has no single answer.
No. Name Formula
1 Acetic Acid  
2 Aluminium Chloride  
3 Aluminium Oxide  
4 Aluminium Sulphate  
5 Ammonium Chloride  
6 Ammonium Sulphate  
7 Barium Bromide  
8 Barium Chloride  
9 Barium Iodide  
10 Barium Sulphate  
11 Bleaching Powder  
12 Calcium Bicarbonate  
13 Calcium Carbonate  
14 Calcium Chloride  
15 Calcium Hydroxide  
16 Calcium Nitrate  
17 Calcium Oxide  
18 Carbon Chloride  
19 Carbon Dioxide  
20 Carbon Monoxide  
21 Copper [Cupric] Carbonate  
22 Copper [Cupric] Chloride  
23 Copper [Cupric] Hydroxide  
24 Copper [Cupric] Oxide  
25 Copper One Oxide  
26 Copper One Sulphide  
27 Copper Two Nitrate  
28 Copper Two Sulphate  
29 Hydrogen Chloride  
30 Hydrogen Nitrate  
31 Hydrogen Sulphate  
32 Hydrogen Sulphide  
33 Hydrogen Sulphite  
34 Iron Three Oxide  
35 Iron Two Chloride  
36 Iron Two Sulphate  
37 Iron Two Three Oxide  
38 Lead [Plumbous] Chloride  
39 Lead [Plumbous] Nitrate  
40 Lead [Plumbous] Oxide  
41 Magnesium Chloride  
42 Magnesium Hydroxide  
43 Magnesium Oxide  
44 Manganese Four Oxide  
45 Manganese Two Chloride  
46 Mercury [Mercuric] Oxide  
47 Mercury [Mercuric] Sulphide  
48 Methanol  
49 Nitrogen Dioxide  
50 Nitrogen Hydride  
51 Potassium Bromide  
52 Potassium Carbonate  
53 Potassium Hydroxide  
54 Potassium Iodide  
55 Potassium Nitrate  
56 Potassium Oxide  
57 Potassium Sulphate  
58 Silver Bromide  
59 Silver Chloride  
60 Silver Nitrate  
61 Sodium Aluminate  
62 Sodium Bicarbonate  
63 Sodium Carbonate  
64 Sodium Chloride  
65 Sodium Hydroxide  
66 Sodium Nitrate  
67 Sodium Oxide  
68 Sodium Phosphate  
69 Sodium Sulphate  
70 Sodium Sulphide  
71 Sodium Sulphite  
72 Sodium Zincate  
73 Sulphur Dioxide  
74 Sulphur Trioxide  
75 Zinc Carbonate  
76 Zinc Nitrate  
77 Zinc Oxide  
78 Zinc Sulphate  
79 Zinc Sulphide  

Balance the equation

Balance each by changing the coefficients only. A subscript is part of the formula and is never changed.
No. Equation Condition
1 HCl plus NaOH → NaCl plus H2O —
2 MgO plus H2O → Mg(OH)2 —
3 CO2 plus Ca(OH)2 → CaCO3 plus H2O —
4 Cu plus H2O plus CO2 plus O2 → Cu(OH)2 plus CuCO3 —
5 SO2 plus H2O → H2SO3 —
6 CuSO4 plus Zn → ZnSO4 plus Cu —
7 Zn plus H2SO4 → ZnSO4 plus H2 —
8 Fe plus H2O → Fe3O4 plus H2 steam
9 CO plus H2 → CH3OH —
10 H2 plus Cl2 → HCl —
11 BaCl2 plus Al2(SO4)3 → BaSO4 plus AlCl3 —
12 Na plus H2O → NaOH plus H2 —
13 BaCl2 plus Na2SO4 → BaSO4 plus NaCl —
14 CaO plus H2O → Ca(OH)2 —
15 C plus O2 → CO2 —
16 H2 plus O2 → H2O —
17 CH4 plus O2 → CO2 plus H2O —
18 FeSO4 → Fe2O3 plus SO2 plus SO3 heat
19 CaCO3 → CaO plus CO2 heat
20 Pb(NO3)2 → PbO plus NO2 plus O2 heat
21 AgCl → Ag plus Cl2 sunlight
22 AgBr → Ag plus Br2 sunlight
23 Fe plus CuSO4 → FeSO4 plus Cu —
24 Pb plus CuCl2 → PbCl2 plus Cu —
25 Cu plus O2 → CuO —
26 CuO plus H2 → Cu plus H2O —
27 ZnO plus C → Zn plus CO —
28 MnO2 plus HCl → MnCl2 plus H2O plus Cl2 —
29 Na plus O2 → Na2O —
30 PbO plus C → Pb plus CO2 —
31 Fe2O3 plus Al → Al2O3 plus Fe —
32 NaOH plus H2SO4 → Na2SO4 plus H2O —
33 H2 plus N2 → NH3 —
34 H2S plus O2 → H2O plus SO2 —
35 K plus H2O → KOH plus H2 —
36 HNO3 plus Ca(OH)2 → Ca(NO3)2 plus H2O —
37 NaCl plus AgNO3 → AgCl plus NaNO3 —
38 BaCl2 plus H2SO4 → BaSO4 plus HCl —
39 Zn plus AgNO3 → Zn(NO3)2 plus Ag —
40 Al plus CuCl2 → AlCl3 plus Cu —
41 BaCl2 plus K2SO4 → BaSO4 plus KCl —
42 KBr plus BaI2 → KI plus BaBr2 —
43 ZnCO3 → ZnO plus CO2 —
44 Mg plus HCl → MgCl2 plus H2 —
45 NaOH plus Zn → Na2ZnO2 plus H2 —
46 Na2CO3 plus HCl → NaCl plus H2O plus CO2 —
47 NaHCO3 plus HCl → NaCl plus H2O plus CO2 —
48 CaCO3 plus H2O plus CO2 → Ca(HCO3)2 —
49 NaCl plus H2O → NaOH plus Cl2 plus H2 electrolysis
50 Ca(OH)2 plus Cl2 → CaOCl2 plus H2O —
51 NaCl plus H2O plus CO2 plus NH3 → NH4Cl plus NaHCO3 —
52 NaHCO3 → Na2CO3 plus H2O plus CO2 heat
53 Al plus H2SO4 → Al2(SO4)3 plus H2 —
54 Fe plus HCl → FeCl2 plus H2 dilute acid
55 Al plus O2 → Al2O3 —
56 Al2O3 plus HCl → AlCl3 plus H2O —
57 Al2O3 plus NaOH → NaAlO2 plus H2O —
58 Na2O plus H2O → NaOH —
59 K2O plus H2O → KOH —
60 Ca plus H2O → Ca(OH)2 plus H2 —
61 Al plus H2O → Al2O3 plus H2 —
62 HgS plus O2 → HgO plus SO2 —
63 HgO → Hg plus O2 heat
64 Cu2O plus Cu2S → Cu plus SO2 —
65 ZnS plus O2 → ZnO plus SO2 —
66 MnO2 plus Al → Mn plus Al2O3 —
67 S plus O2 → SO2 —
Answers — CBSE

Mark the set against these after it is finished, not during. If you are printing the sheet and want the answers on it, leave this block open before you print — it starts a new page.

Answers — write the formula, CBSE.
No. Name Formula Built from
1 Acetic Acid CH3COOH Not built by the criss-cross rule
2 Aluminium Chloride AlCl3 Aluminium 3 · Chloride 1
3 Aluminium Oxide Al2O3 Aluminium 3 · Oxide 2
4 Aluminium Sulphate Al2(SO4)3 Aluminium 3 · Sulphate 2
5 Ammonium Chloride NH4Cl Ammonium 1 · Chloride 1
6 Ammonium Sulphate (NH4)2SO4 Ammonium 1 · Sulphate 2
7 Barium Bromide BaBr2 Barium 2 · Bromide 1
8 Barium Chloride BaCl2 Barium 2 · Chloride 1
9 Barium Iodide BaI2 Barium 2 · Iodide 1
10 Barium Sulphate BaSO4 Barium 2 · Sulphate 2
11 Bleaching Powder CaOCl2 Not built by the criss-cross rule
12 Calcium Bicarbonate Ca(HCO3)2 Calcium 2 · Bicarbonate 1
13 Calcium Carbonate CaCO3 Calcium 2 · Carbonate 2
14 Calcium Chloride CaCl2 Calcium 2 · Chloride 1
15 Calcium Hydroxide Ca(OH)2 Calcium 2 · Hydroxide 1
16 Calcium Nitrate Ca(NO3)2 Calcium 2 · Nitrate 1
17 Calcium Oxide CaO Calcium 2 · Oxide 2
18 Carbon Chloride CCl4 Carbon 4 · Chloride 1
19 Carbon Dioxide CO2 Carbon 4 · Oxide 2
20 Carbon Monoxide CO Not built by the criss-cross rule
21 Copper [Cupric] Carbonate CuCO3 Copper [Cupric] 2 · Carbonate 2
22 Copper [Cupric] Chloride CuCl2 Copper [Cupric] 2 · Chloride 1
23 Copper [Cupric] Hydroxide Cu(OH)2 Copper [Cupric] 2 · Hydroxide 1
24 Copper [Cupric] Oxide CuO Copper [Cupric] 2 · Oxide 2
25 Copper One Oxide Cu2O Copper [Cuprous] 1 · Oxide 2
26 Copper One Sulphide Cu2S Copper [Cuprous] 1 · Sulphide 2
27 Copper Two Nitrate Cu(NO3)2 Copper [Cupric] 2 · Nitrate 1
28 Copper Two Sulphate CuSO4 Copper [Cupric] 2 · Sulphate 2
29 Hydrogen Chloride HCl Hydrogen 1 · Chloride 1
30 Hydrogen Nitrate HNO3 Hydrogen 1 · Nitrate 1
31 Hydrogen Sulphate H2SO4 Hydrogen 1 · Sulphate 2
32 Hydrogen Sulphide H2S Hydrogen 1 · Sulphide 2
33 Hydrogen Sulphite H2SO3 Hydrogen 1 · Sulphite 2
34 Iron Three Oxide Fe2O3 Iron [Ferric] 3 · Oxide 2
35 Iron Two Chloride FeCl2 Iron [Ferrous] 2 · Chloride 1
36 Iron Two Sulphate FeSO4 Iron [Ferrous] 2 · Sulphate 2
37 Iron Two Three Oxide Fe3O4 Not built by the criss-cross rule
38 Lead [Plumbous] Chloride PbCl2 Lead [Plumbous] 2 · Chloride 1
39 Lead [Plumbous] Nitrate Pb(NO3)2 Lead [Plumbous] 2 · Nitrate 1
40 Lead [Plumbous] Oxide PbO Lead [Plumbous] 2 · Oxide 2
41 Magnesium Chloride MgCl2 Magnesium 2 · Chloride 1
42 Magnesium Hydroxide Mg(OH)2 Magnesium 2 · Hydroxide 1
43 Magnesium Oxide MgO Magnesium 2 · Oxide 2
44 Manganese Four Oxide MnO2 Manganese 4 · Oxide 2
45 Manganese Two Chloride MnCl2 Manganese 2 · Chloride 1
46 Mercury [Mercuric] Oxide HgO Mercury [Mercuric] 2 · Oxide 2
47 Mercury [Mercuric] Sulphide HgS Mercury [Mercuric] 2 · Sulphide 2
48 Methanol CH3OH Not built by the criss-cross rule
49 Nitrogen Dioxide NO2 Not built by the criss-cross rule
50 Nitrogen Hydride NH3 Nitrogen 3 · Hydride 1
51 Potassium Bromide KBr Potassium 1 · Bromide 1
52 Potassium Carbonate K2CO3 Potassium 1 · Carbonate 2
53 Potassium Hydroxide KOH Potassium 1 · Hydroxide 1
54 Potassium Iodide KI Potassium 1 · Iodide 1
55 Potassium Nitrate KNO3 Potassium 1 · Nitrate 1
56 Potassium Oxide K2O Potassium 1 · Oxide 2
57 Potassium Sulphate K2SO4 Potassium 1 · Sulphate 2
58 Silver Bromide AgBr Silver 1 · Bromide 1
59 Silver Chloride AgCl Silver 1 · Chloride 1
60 Silver Nitrate AgNO3 Silver 1 · Nitrate 1
61 Sodium Aluminate NaAlO2 Sodium 1 · Aluminate 1
62 Sodium Bicarbonate NaHCO3 Sodium 1 · Bicarbonate 1
63 Sodium Carbonate Na2CO3 Sodium 1 · Carbonate 2
64 Sodium Chloride NaCl Sodium 1 · Chloride 1
65 Sodium Hydroxide NaOH Sodium 1 · Hydroxide 1
66 Sodium Nitrate NaNO3 Sodium 1 · Nitrate 1
67 Sodium Oxide Na2O Sodium 1 · Oxide 2
68 Sodium Phosphate Na3PO4 Sodium 1 · Phosphate 3
69 Sodium Sulphate Na2SO4 Sodium 1 · Sulphate 2
70 Sodium Sulphide Na2S Sodium 1 · Sulphide 2
71 Sodium Sulphite Na2SO3 Sodium 1 · Sulphite 2
72 Sodium Zincate Na2ZnO2 Sodium 1 · Zincate 2
73 Sulphur Dioxide SO2 Not built by the criss-cross rule
74 Sulphur Trioxide SO3 Not built by the criss-cross rule
75 Zinc Carbonate ZnCO3 Zinc 2 · Carbonate 2
76 Zinc Nitrate Zn(NO3)2 Zinc 2 · Nitrate 1
77 Zinc Oxide ZnO Zinc 2 · Oxide 2
78 Zinc Sulphate ZnSO4 Zinc 2 · Sulphate 2
79 Zinc Sulphide ZnS Zinc 2 · Sulphide 2
Answers — balance the equation, CBSE.
No. Balanced
1 HCl plus NaOH → NaCl plus H2O
2 MgO plus H2O → Mg(OH)2
3 CO2 plus Ca(OH)2 → CaCO3 plus H2O
4 2Cu plus H2O plus CO2 plus O2 → Cu(OH)2 plus CuCO3
5 SO2 plus H2O → H2SO3
6 CuSO4 plus Zn → ZnSO4 plus Cu
7 Zn plus H2SO4 → ZnSO4 plus H2
8 3Fe plus 4H2O → Fe3O4 plus 4H2
9 CO plus 2H2 → CH3OH
10 H2 plus Cl2 → 2HCl
11 3BaCl2 plus Al2(SO4)3 → 3BaSO4 plus 2AlCl3
12 2Na plus 2H2O → 2NaOH plus H2
13 BaCl2 plus Na2SO4 → BaSO4 plus 2NaCl
14 CaO plus H2O → Ca(OH)2
15 C plus O2 → CO2
16 2H2 plus O2 → 2H2O
17 CH4 plus 2O2 → CO2 plus 2H2O
18 2FeSO4 → Fe2O3 plus SO2 plus SO3
19 CaCO3 → CaO plus CO2
20 2Pb(NO3)2 → 2PbO plus 4NO2 plus O2
21 2AgCl → 2Ag plus Cl2
22 2AgBr → 2Ag plus Br2
23 Fe plus CuSO4 → FeSO4 plus Cu
24 Pb plus CuCl2 → PbCl2 plus Cu
25 2Cu plus O2 → 2CuO
26 CuO plus H2 → Cu plus H2O
27 ZnO plus C → Zn plus CO
28 MnO2 plus 4HCl → MnCl2 plus 2H2O plus Cl2
29 4Na plus O2 → 2Na2O
30 2PbO plus C → 2Pb plus CO2
31 Fe2O3 plus 2Al → Al2O3 plus 2Fe
32 2NaOH plus H2SO4 → Na2SO4 plus 2H2O
33 3H2 plus N2 → 2NH3
34 2H2S plus 3O2 → 2H2O plus 2SO2
35 2K plus 2H2O → 2KOH plus H2
36 2HNO3 plus Ca(OH)2 → Ca(NO3)2 plus 2H2O
37 NaCl plus AgNO3 → AgCl plus NaNO3
38 BaCl2 plus H2SO4 → BaSO4 plus 2HCl
39 Zn plus 2AgNO3 → Zn(NO3)2 plus 2Ag
40 2Al plus 3CuCl2 → 2AlCl3 plus 3Cu
41 BaCl2 plus K2SO4 → BaSO4 plus 2KCl
42 2KBr plus BaI2 → 2KI plus BaBr2
43 ZnCO3 → ZnO plus CO2
44 Mg plus 2HCl → MgCl2 plus H2
45 2NaOH plus Zn → Na2ZnO2 plus H2
46 Na2CO3 plus 2HCl → 2NaCl plus H2O plus CO2
47 NaHCO3 plus HCl → NaCl plus H2O plus CO2
48 CaCO3 plus H2O plus CO2 → Ca(HCO3)2
49 2NaCl plus 2H2O → 2NaOH plus Cl2 plus H2
50 Ca(OH)2 plus Cl2 → CaOCl2 plus H2O
51 NaCl plus H2O plus CO2 plus NH3 → NH4Cl plus NaHCO3
52 2NaHCO3 → Na2CO3 plus H2O plus CO2
53 2Al plus 3H2SO4 → Al2(SO4)3 plus 3H2
54 Fe plus 2HCl → FeCl2 plus H2
55 4Al plus 3O2 → 2Al2O3
56 Al2O3 plus 6HCl → 2AlCl3 plus 3H2O
57 Al2O3 plus 2NaOH → 2NaAlO2 plus H2O
58 Na2O plus H2O → 2NaOH
59 K2O plus H2O → 2KOH
60 Ca plus 2H2O → Ca(OH)2 plus H2
61 2Al plus 3H2O → Al2O3 plus 3H2
62 2HgS plus 3O2 → 2HgO plus 2SO2
63 2HgO → 2Hg plus O2
64 2Cu2O plus Cu2S → 6Cu plus SO2
65 2ZnS plus 3O2 → 2ZnO plus 2SO2
66 3MnO2 plus 4Al → 3Mn plus 2Al2O3
67 S plus O2 → SO2

SSLC · Classes 8 to 10

Secondary School Leaving Certificate, Kerala State syllabus

52 formulas to write and 51 equations to balance, compiled from this board's own textbooks. The full chapter-by-chapter list is on its syllabus page.

Write the formula

Write the chemical formula for each. Where a metal has two states, the state is given — without it the question has no single answer.
No. Name Formula
1 Aluminium Chloride  
2 Aluminium Hydroxide  
3 Aluminium Oxide  
4 Aluminium Sulphate  
5 Ammonium Chloride  
6 Ammonium Hydroxide  
7 Barium Chloride  
8 Barium Sulphate  
9 Calcium Carbonate  
10 Calcium Chloride  
11 Calcium Hydroxide  
12 Calcium Oxide  
13 Calcium Sulphate  
14 Carbon Dioxide  
15 Carbon Monoxide  
16 Copper Two Nitrate  
17 Copper Two Sulphate  
18 Hydrogen Carbonate  
19 Hydrogen Chloride  
20 Hydrogen Nitrate  
21 Hydrogen Phosphate  
22 Hydrogen Sulphate  
23 Hydrogen Sulphite  
24 Iron Two Chloride  
25 Iron Two Sulphate  
26 Magnesium Chloride  
27 Magnesium Fluoride  
28 Magnesium Hydroxide  
29 Magnesium Nitrate  
30 Magnesium Oxide  
31 Magnesium Sulphate  
32 Manganese Two Chloride  
33 Nitrogen Dioxide  
34 Nitrogen Hydride  
35 Potassium Chlorate  
36 Potassium Chloride  
37 Potassium Hydroxide  
38 Potassium Oxide  
39 Potassium Permanganate  
40 Potassium Phosphate  
41 Silver Chloride  
42 Silver Nitrate  
43 Sodium Bromide  
44 Sodium Chloride  
45 Sodium Hydride  
46 Sodium Hydroxide  
47 Sodium Nitrate  
48 Sulphur Dioxide  
49 Sulphur Trioxide  
50 Zinc Chloride  
51 Zinc Oxide  
52 Zinc Sulphate  

Balance the equation

Balance each by changing the coefficients only. A subscript is part of the formula and is never changed.
No. Equation Condition
1 Zn plus HCl → ZnCl2 plus H2 —
2 C plus O2 → CO2 —
3 H2 plus Cl2 → HCl —
4 H2 plus O2 → H2O —
5 Mg plus O2 → MgO —
6 N2 plus H2 → NH3 —
7 H2O2 → H2O plus O2 —
8 CH4 plus O2 → CO2 plus H2O —
9 N2 plus O2 → NO —
10 CaCO3 → CaO plus CO2 heat
11 H2 plus I2 → HI —
12 Fe plus HCl → FeCl2 plus H2 —
13 CO2 plus C → CO —
14 Mg plus HCl → MgCl2 plus H2 —
15 Na plus H2O → NaOH plus H2 —
16 Al plus HCl → AlCl3 plus H2 —
17 Al plus O2 → Al2O3 —
18 SO2 plus O2 → SO3 —
19 BaCl2 plus H2SO4 → BaSO4 plus HCl —
20 Mg plus Cl2 → MgCl2 —
21 Mg plus F2 → MgF2 —
22 Na plus Cl2 → NaCl —
23 CaCO3 plus HCl → CaCl2 plus H2O plus CO2 —
24 MgO plus H2O → Mg(OH)2 —
25 CaO plus H2O → Ca(OH)2 —
26 NaOH plus HCl → NaCl plus H2O —
27 Mg(OH)2 plus H2SO4 → MgSO4 plus H2O —
28 Zn plus H2SO4 → ZnSO4 plus H2 —
29 Mg plus HNO3 → Mg(NO3)2 plus H2 —
30 Zn plus CuSO4 → ZnSO4 plus Cu —
31 NaBr plus Cl2 → NaCl plus Br2 —
32 S plus O2 → SO2 —
33 H2 plus S → H2S —
34 Na plus H2 → NaH —
35 NaCl → Na plus Cl2 electrolysis
36 KClO3 → KCl plus O2 heat
37 NO plus O2 → NO2 —
38 KMnO4 plus HCl → KCl plus MnCl2 plus H2O plus Cl2 —
39 Cl2 plus H2O → HCl plus HOCl —
40 NaCl plus AgNO3 → AgCl plus NaNO3 —
41 Na2SO4 plus BaCl2 → BaSO4 plus NaCl —
42 KCl plus AgNO3 → AgCl plus KNO3 —
43 ZnSO4 plus BaCl2 → BaSO4 plus ZnCl2 —
44 H2O → H2 plus O2 electrolysis
45 FeSO4 plus Zn → ZnSO4 plus Fe —
46 AgNO3 plus Cu → Cu(NO3)2 plus Ag —
47 NH4Cl plus Ca(OH)2 → CaCl2 plus H2O plus NH3 —
48 NH3 plus H2O → NH4OH —
49 NH3 plus HCl → NH4Cl —
50 C plus H2SO4 → CO2 plus H2O plus SO2 —
51 Cu plus H2SO4 → CuSO4 plus SO2 plus H2O —
Answers — SSLC

Mark the set against these after it is finished, not during. If you are printing the sheet and want the answers on it, leave this block open before you print — it starts a new page.

Answers — write the formula, SSLC.
No. Name Formula Built from
1 Aluminium Chloride AlCl3 Aluminium 3 · Chloride 1
2 Aluminium Hydroxide Al(OH)3 Aluminium 3 · Hydroxide 1
3 Aluminium Oxide Al2O3 Aluminium 3 · Oxide 2
4 Aluminium Sulphate Al2(SO4)3 Aluminium 3 · Sulphate 2
5 Ammonium Chloride NH4Cl Ammonium 1 · Chloride 1
6 Ammonium Hydroxide NH4OH Ammonium 1 · Hydroxide 1
7 Barium Chloride BaCl2 Barium 2 · Chloride 1
8 Barium Sulphate BaSO4 Barium 2 · Sulphate 2
9 Calcium Carbonate CaCO3 Calcium 2 · Carbonate 2
10 Calcium Chloride CaCl2 Calcium 2 · Chloride 1
11 Calcium Hydroxide Ca(OH)2 Calcium 2 · Hydroxide 1
12 Calcium Oxide CaO Calcium 2 · Oxide 2
13 Calcium Sulphate CaSO4 Calcium 2 · Sulphate 2
14 Carbon Dioxide CO2 Carbon 4 · Oxide 2
15 Carbon Monoxide CO Not built by the criss-cross rule
16 Copper Two Nitrate Cu(NO3)2 Copper [Cupric] 2 · Nitrate 1
17 Copper Two Sulphate CuSO4 Copper [Cupric] 2 · Sulphate 2
18 Hydrogen Carbonate H2CO3 Hydrogen 1 · Carbonate 2
19 Hydrogen Chloride HCl Hydrogen 1 · Chloride 1
20 Hydrogen Nitrate HNO3 Hydrogen 1 · Nitrate 1
21 Hydrogen Phosphate H3PO4 Hydrogen 1 · Phosphate 3
22 Hydrogen Sulphate H2SO4 Hydrogen 1 · Sulphate 2
23 Hydrogen Sulphite H2SO3 Hydrogen 1 · Sulphite 2
24 Iron Two Chloride FeCl2 Iron [Ferrous] 2 · Chloride 1
25 Iron Two Sulphate FeSO4 Iron [Ferrous] 2 · Sulphate 2
26 Magnesium Chloride MgCl2 Magnesium 2 · Chloride 1
27 Magnesium Fluoride MgF2 Magnesium 2 · Fluoride 1
28 Magnesium Hydroxide Mg(OH)2 Magnesium 2 · Hydroxide 1
29 Magnesium Nitrate Mg(NO3)2 Magnesium 2 · Nitrate 1
30 Magnesium Oxide MgO Magnesium 2 · Oxide 2
31 Magnesium Sulphate MgSO4 Magnesium 2 · Sulphate 2
32 Manganese Two Chloride MnCl2 Manganese 2 · Chloride 1
33 Nitrogen Dioxide NO2 Not built by the criss-cross rule
34 Nitrogen Hydride NH3 Nitrogen 3 · Hydride 1
35 Potassium Chlorate KClO3 Potassium 1 · Chlorate 1
36 Potassium Chloride KCl Potassium 1 · Chloride 1
37 Potassium Hydroxide KOH Potassium 1 · Hydroxide 1
38 Potassium Oxide K2O Potassium 1 · Oxide 2
39 Potassium Permanganate KMnO4 Potassium 1 · Permanganate 1
40 Potassium Phosphate K3PO4 Potassium 1 · Phosphate 3
41 Silver Chloride AgCl Silver 1 · Chloride 1
42 Silver Nitrate AgNO3 Silver 1 · Nitrate 1
43 Sodium Bromide NaBr Sodium 1 · Bromide 1
44 Sodium Chloride NaCl Sodium 1 · Chloride 1
45 Sodium Hydride NaH Sodium 1 · Hydride 1
46 Sodium Hydroxide NaOH Sodium 1 · Hydroxide 1
47 Sodium Nitrate NaNO3 Sodium 1 · Nitrate 1
48 Sulphur Dioxide SO2 Not built by the criss-cross rule
49 Sulphur Trioxide SO3 Not built by the criss-cross rule
50 Zinc Chloride ZnCl2 Zinc 2 · Chloride 1
51 Zinc Oxide ZnO Zinc 2 · Oxide 2
52 Zinc Sulphate ZnSO4 Zinc 2 · Sulphate 2
Answers — balance the equation, SSLC.
No. Balanced
1 Zn plus 2HCl → ZnCl2 plus H2
2 C plus O2 → CO2
3 H2 plus Cl2 → 2HCl
4 2H2 plus O2 → 2H2O
5 2Mg plus O2 → 2MgO
6 N2 plus 3H2 → 2NH3
7 2H2O2 → 2H2O plus O2
8 CH4 plus 2O2 → CO2 plus 2H2O
9 N2 plus O2 → 2NO
10 CaCO3 → CaO plus CO2
11 H2 plus I2 → 2HI
12 Fe plus 2HCl → FeCl2 plus H2
13 CO2 plus C → 2CO
14 Mg plus 2HCl → MgCl2 plus H2
15 2Na plus 2H2O → 2NaOH plus H2
16 2Al plus 6HCl → 2AlCl3 plus 3H2
17 4Al plus 3O2 → 2Al2O3
18 2SO2 plus O2 → 2SO3
19 BaCl2 plus H2SO4 → BaSO4 plus 2HCl
20 2Mg plus 2Cl2 → 2MgCl2
21 2Mg plus 2F2 → 2MgF2
22 2Na plus Cl2 → 2NaCl
23 CaCO3 plus 2HCl → CaCl2 plus H2O plus CO2
24 MgO plus H2O → Mg(OH)2
25 CaO plus H2O → Ca(OH)2
26 NaOH plus HCl → NaCl plus H2O
27 Mg(OH)2 plus H2SO4 → MgSO4 plus 2H2O
28 Zn plus H2SO4 → ZnSO4 plus H2
29 Mg plus 2HNO3 → Mg(NO3)2 plus H2
30 Zn plus CuSO4 → ZnSO4 plus Cu
31 2NaBr plus Cl2 → 2NaCl plus Br2
32 S plus O2 → SO2
33 H2 plus S → H2S
34 2Na plus H2 → 2NaH
35 2NaCl → 2Na plus Cl2
36 2KClO3 → 2KCl plus 3O2
37 2NO plus O2 → 2NO2
38 2KMnO4 plus 16HCl → 2KCl plus 2MnCl2 plus 8H2O plus 5Cl2
39 Cl2 plus H2O → HCl plus HOCl
40 NaCl plus AgNO3 → AgCl plus NaNO3
41 Na2SO4 plus BaCl2 → BaSO4 plus 2NaCl
42 KCl plus AgNO3 → AgCl plus KNO3
43 ZnSO4 plus BaCl2 → BaSO4 plus ZnCl2
44 2H2O → 2H2 plus O2
45 FeSO4 plus Zn → ZnSO4 plus Fe
46 2AgNO3 plus Cu → Cu(NO3)2 plus 2Ag
47 2NH4Cl plus Ca(OH)2 → CaCl2 plus 2H2O plus 2NH3
48 NH3 plus H2O → NH4OH
49 NH3 plus HCl → NH4Cl
50 C plus 2H2SO4 → CO2 plus 2H2O plus 2SO2
51 Cu plus 2H2SO4 → CuSO4 plus SO2 plus 2H2O

Where these come from, and what they are not

Every question above is generated from the inventories on the syllabus pages — the formulas and equations each board's own textbooks set, compiled chapter by chapter by the author of the Playbook. The formulas are checked against the criss-cross rule and the equations are atom-counted, on every build of this site.

None of it is taken from the book. The Language of Chemistry, Playbook® contains 19 exercises and 279 questions of its own, and those stay in the book. That is the reason this page can be given away without a form attached to it — and the reason it is not a substitute for the book, which is gated, marked and sequenced in a way a printed sheet cannot be. Printing and copying are covered on the copyright page.

Two CBSE Class 7 equations are missing from the set above on purpose: the textbook prints them unbalanced, so there is no answer to mark against. Both are shown, counted, and explained on the balancing page.

Questions

Do I have to give an email address to get these?
No. There is no form on this page, nothing to sign up for and nothing to download. The questions and the answers are both on the page, and the page prints.
Where do these questions come from?
From each board’s own syllabus: every formula and every equation the ICSE, CBSE and Kerala SSLC textbooks set, compiled chapter by chapter. None of them is taken from The Language of Chemistry, Playbook® — the book’s own exercises stay in the book.
Can I print these for my class?
Yes. This page is set up to print, and its questions are drawn from published syllabuses rather than from the Playbook. Photocopying the Playbook itself is a different matter and is covered on the copyright page.
Why are the answers hidden?
Because an answer a student can see while attempting the question is not a question. Open the answers after the set is finished, and mark it then.

A sheet is practice. The book is a sequence.

Anyone can hand a student a worksheet. What this page cannot do is stop them going on to equations while the valencies are still being guessed at — and that is the whole of the Playbook's argument: the chapter does not open until the score is made, and below the score the exercises are repeated.

See how the method works Using it at home