Chemical Equations
Chemistry ⇒ Chemical Reactions and Equations
Chemical Equations starts at 7 and continues till grade 12.
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A chemical equation must be balanced to obey which law?
Balance the following equation: Al + O2 → Al2O3
Balance the following equation: Fe + O2 → Fe2O3
Explain why it is necessary to balance a chemical equation.
Fill in the blank: In the equation 2Mg + O2 → 2MgO, the number of oxygen atoms on the left is ________.
Fill in the blank: The equation 2K + 2H2O → 2KOH + H2 is an example of a ________ reaction.
Fill in the blank: The equation N2 + 3H2 → 2NH3 is an example of a ________ reaction.
In the equation: 2KClO3 → 2KCl + 3O2, how many molecules of oxygen are produced when 2 moles of potassium chlorate decompose?
Which of the following equations is not balanced?
(1) 2K + 2H2O → 2KOH + H2
(2) N2 + 3H2 → 2NH3
(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 balanced equation for the reaction of iron with sulfur to form iron(II) sulfide?
(1) Fe + S → FeS
(2) 2Fe + S → 2FeS
(3) Fe + 2S → FeS2
(4) 2Fe + 3S → Fe2S3
Which of the following is a correct representation of a chemical reaction?
(1) 2H2 + O2 → 2H2O
(2) H2 + O2 → H2O
(3) H2 + O2 → 2H2O
(4) 2H2 + 2O2 → 2H2O
Fill in the blank: In a chemical equation, the substances written on the left side of the arrow are called ________.
Fill in the blank: In the chemical equation 2Na + Cl2 → 2NaCl, Na is a ________.
Fill in the blank: In the equation 2Mg + O2 → 2MgO, the number of oxygen atoms on the left is ________.
Fill in the blank: The arrow (→) in a chemical equation is read as ________.
Is the following equation balanced?
2Al + 3Cl2 → 2AlCl3
Is the following equation balanced?
C + O2 → CO
Is the following equation balanced?
Na + Cl2 → NaCl
Is the following statement true or false?
A balanced chemical equation always has the same number of molecules on both sides.
