Question
If a piece of blackboard chalk is heated strongly, the mass of the chalk decreases substantially, and the chalk is converted into a fine powder. What evidence is there for a chemical reaction having taken place when the chalk is heated?
Step 1
This change is typically irreversible. Show more…
Show all steps
Your feedback will help us improve your experience
Annelies Ondersma and 70 other Chemistry 101 educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Chalkboard chalk is made from calcium carbonate and calcium sulfate, with minor impurities such as $\mathrm{SiO}_{2} .$ Only the $\mathrm{CaCO}_{3}$ reacts with dilute $\mathrm{HCl}(\mathrm{aq})$ What is the mass percent $\mathrm{CaCO}_{3}$ in a piece of chalk if a $3.28 \mathrm{g}$ sample yields $0.981 \mathrm{g} \mathrm{CO}_{2}(\mathrm{g}) ?$ $\mathrm{CaCO}_{3}(\mathrm{s})+2 \mathrm{HCl}(\mathrm{aq}) \longrightarrow$ $\mathrm{CaCl}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{g})$.
Which of the following is evidence for a chemical reaction? (a) Heating copper in air produces a black solid. (b) Heating copper in a vacuum gives a red-brown film.
What is the only way to prove that a chemical reaction has occurred?
Chemical Equations and Reactions
Describing Chemical Reactions
Transcript
600,000+
Students learning Chemistry with Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD
