Chemical change
Explanation:
Often times, in chemical reactions, a temperature change indicates that a chemical change has occurred.
What is a chemical change?
- It is a kind of change in which new products are formed.
- Chemical changes are usually accompanied by energy changes in reactions.
- The process is not easily reversible.
- It usually involve a change in mass.
- Requires considerable amount of energy
When temperature change occurs, it usually denotes chemical change.
learn more:
Chemical change brainly.com/question/9388643
#learnwithBrainly
Answer:
236.8 g
Explanation:
From the reaction equation;
CaC2 + 2H2O(I) --------> C2H2(g) + Ca(OH)2(aq)
Since;
1 mole of CaC2 yields 1 mole of Ca(OH)2
It follows that 3.20 moles of CaC2 also yields 3.2 moles of Ca(OH)2
Mass of Ca(OH)2 = number of moles * molar mass
molar mass of Ca(OH)2 = 74 g/mol
Mass of Ca(OH)2 = 3.20 moles * 74 g/mol =
Mass of Ca(OH)2 = 236.8 g
Answer:
Diamond and graphite are allotropes of carbon.
Explanation:
Diamond has a close packed crystal structure which is responsible for its extreme hardness. In it, each carbon atom is sp³ hybridised and bonded to four other carbon atoms in a tetrahedral arrangement. Diamond has a hardness of 10 on mohs scale with a cubic crystal form.
Note: allotropes of an element have different molecular structure.
Graphite on the other hand is made up of layers of hexagonal structure that are weakly bonded by van-der-waals forces. This layered arrangement explains its softness/slippery feeling and hence it is used as a lubricant. In each layer, each carbon atom is sp² hybridised and bonded to three other carbon atoms in a trigonal planar arrangement.
The presence of 
electrons in the layers accounts for its ability to conduct electricity.
