Procedures that are likely a chemical change are:
- Bubbles were produced when iron was placed in acid.
- Two liquids were combined, and a solid appeared
- A white substance turned blue when water was added.
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%
Iodine is decolorized.
The first reaction stated in the question occurs as follows;
2 KI (aq) + 2 H2SO4 (aq) + MnO2 (s) → MnSO4 (aq) + K2SO4 (aq) + I2 (s) + 2 H2O (l)
The reaction here is the formation of iodine from MnO2 and KI in the presence of dropwise H2SO4.
Hypo is the common name of sodium thio-sulphate or sodium hypo-sulfite.
The equation of the titration reaction is;
2Na2S2O3 + I2→ Na2S4O6 + 2NaI
When this reaction takes place, iodine is decolorized due to its reduction to I^-.