Chemical Equations
Chemistry ⇒ Chemical Reactions and Equations
Chemical Equations starts at 7 and continues till grade 12.
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See sample questions for grade 8
A student writes: 2Na + 2H2O → 2NaOH + H2. How many sodium atoms are present on the product side?
Balance the following equation: ___Al + ___O2 → ___Al2O3
Balance the following equation: ___C2H6 + ___O2 → ___CO2 + ___H2O
Balance the following equation: ___Na + ___Cl2 → ___NaCl
Explain why it is incorrect to balance a chemical equation by changing the subscripts in chemical formulas.
If 2H2 + O2 → 2H2O, how many molecules of water are produced when 4 molecules of hydrogen react with 2 molecules of oxygen?
A student writes the equation: Fe + CuSO4 → FeSO4 + Cu. Is this equation balanced?
A student writes: 2Na + 2H2O → 2NaOH + H2. How many sodium atoms are present on the product side?
Which of the following best describes a balanced chemical equation? (1) The number of atoms of each element is the same on both sides. (2) The number of molecules is the same on both sides. (3) The number of compounds is the same on both sides. (4) The number of electrons is the same on both sides.
Which of the following equations is not balanced? (1) N2 + 3H2 → 2NH3 (2) C + O2 → CO2 (3) H2 + Cl2 → 2HCl (4) Na + H2O → NaOH + H2
Which of the following is a balanced chemical equation? (1) H2 + O2 → H2O (2) 2H2 + O2 → 2H2O (3) H2 + 2O2 → 2H2O (4) 2H2 + 2O2 → 2H2O
Which of the following is a product in the reaction: 2H2O2 → 2H2O + O2? (1) H2O2 (2) H2O (3) O2 (4) Both 2 and 3
Fill in the blank: In the equation 2H2 + O2 → 2H2O, the total number of hydrogen atoms on the product side is ___.
Fill in the blank: In the equation 2KClO3 → 2KCl + 3___, the blank should be filled with ______.
Fill in the blank: In the equation Zn + 2HCl → ZnCl2 + ___, the blank should be filled with ______.
Fill in the blank: The chemical equation for the reaction of iron with oxygen to form iron(III) oxide is 4Fe + 3O2 → ___Fe2O3.
A student writes the equation: Fe + CuSO4 → FeSO4 + Cu. Is this equation balanced?
True or False: In a chemical equation, the substances on the left side of the arrow are called products.
True or False: Subscripts in chemical formulas can be changed to balance a chemical equation.
True or False: The arrow (→) in a chemical equation means 'yields' or 'produces'.
