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Chemical Equations

Chemistry ⇒ Chemical Reactions and Equations

Chemical Equations starts at 7 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Chemical Equations. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
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?
In a chemical equation, what does a double arrow (⇌) indicate?
In the equation 2Mg + O2 → 2MgO, how many atoms of oxygen are present on the reactant side?
What do the coefficients in a chemical equation represent?
What does the symbol (aq) mean in a chemical equation?
What is a chemical equation?
What is meant by the term 'product' in a chemical equation?
What is meant by the term 'reactant' in a chemical equation?
What is the product formed when calcium reacts with water? Write the chemical equation.
What is the purpose of balancing a chemical equation?
Write the balanced chemical equation for the reaction between hydrochloric acid and sodium hydroxide.
Write the balanced chemical equation for the reaction of carbon dioxide with water to form carbonic acid.
A chemical equation is written as: 2SO2 + O2 → 2SO3. If you start with 4 molecules of SO2, how many molecules of SO3 will be produced?
A student writes the following equation: CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g). How many different physical states are represented in this equation?
Describe the difference between a word equation and a chemical equation, giving an example of each.