Answer:
Percentage of copper = 88%
Explanation:
Given data:
Mass of copper = 51.2 g
Mass of tin = 6.84 g
Percentage of copper = ?
Solution:
Formula:
Percentage of copper = mass of copper / total mass × 100
Now we will determine the total mass:
Total mass = mass of copper + mass of tin
Total mass = 51.2 g + 6.84 g
Total mass = 58.04 g
Now we will calculate the percentage of copper.
Percentage of copper = 51.2 g / 58.04 g × 100
Percentage of copper = 0.88 × 100
Percentage of copper = 88%
It comes to from the chemical reaction itself. Exothermic reaction release heat because the energy level of the products is lower than that of the reactants. Therefore, the net enthalpy change of the reaction is negative (-), meaning heat or light (or any other form of energy) is released into the environment. An example of an exothermic reaction is the combustion of fuel.
Answer:
false
Explanation:
when heat is added to atoms, the molecules vibrate more quickly, because it increases the heat energy, which in turn, increases the particle movement
Chemical energy is released