Science9-12+
Chemical Reaction Analysis: Mercury and Hydrochloric Acid
By Aye S.
A one-page, single-sided support sheet for 10th graders to complete before a chemical reaction quiz, taking roughly 20-30 minutes. Students classify reactants and products in Hg + 2 HCl → HgCl₂ + H₂, draw particle-level models, count atoms of each element, and explain how conservation of matter and observable changes in physical state show that a reaction has occurred.
Customize for your classroom
Teacher Guide & Tips
- Use as a pre-quiz review sheet, either independently or in pairs, after students have learned balancing equations and the law of conservation of matter.
- Discussion question: Why does the mass of the reactants equal the mass of the products even though the substances look completely different?
- Scaffold for struggling readers: Provide a periodic table and a sample completed row (for example, counting atoms in H₂O) before students begin the atom inventory.
- Extension for advanced students: Ask them to predict observable signs of reaction, such as gas bubbling or a color change, and justify those predictions using the states of matter listed.
- Estimated time: about 20-30 minutes, including a brief whole-class debrief on the observable evidence of a reaction.
Science9-12+
Chemical Reaction Analysis: Mercury and Hydrochloric Acid
By Aye S.
A one-page, single-sided support sheet for 10th graders to complete before a chemical reaction quiz, taking roughly 20-30 minutes. Students classify reactants and products in Hg + 2 HCl → HgCl₂ + H₂, draw particle-level models, count atoms of each element, and explain how conservation of matter and observable changes in physical state show that a reaction has occurred.
Customize for your classroom
Teacher Guide & Tips
- Use as a pre-quiz review sheet, either independently or in pairs, after students have learned balancing equations and the law of conservation of matter.
- Discussion question: Why does the mass of the reactants equal the mass of the products even though the substances look completely different?
- Scaffold for struggling readers: Provide a periodic table and a sample completed row (for example, counting atoms in H₂O) before students begin the atom inventory.
- Extension for advanced students: Ask them to predict observable signs of reaction, such as gas bubbling or a color change, and justify those predictions using the states of matter listed.
- Estimated time: about 20-30 minutes, including a brief whole-class debrief on the observable evidence of a reaction.