Give the names and formulae of three ores which are concentrated by froth floatation process.

Answer

To answer the question regarding the names and formulae of three ores that are concentrated by the froth flotation process, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Froth Flotation Process**:
- The froth flotation process is primarily used for the concentration of sulfide ores. This method involves the separation of hydrophobic materials from hydrophilic ones by utilizing differences in their surface properties.

2. **Identifying Sulfide Ores**:
- Since the question specifically asks for ores concentrated by the froth flotation process, we need to focus on sulfide ores.

3. **Listing Three Ores**:
- We can identify three common sulfide ores that are concentrated using the froth flotation method:
- **Galena**: This is the primary ore of lead.
- **Zinc Blende**: This is the primary ore of zinc.
- **Cinnabar**: This is the primary ore of mercury.

4. **Writing the Formulae**:
- For each of the identified ores, we can write their chemical formulae:
- **Galena**: PbS (Lead Sulfide)
- **Zinc Blende**: ZnS (Zinc Sulfide)
- **Cinnabar**: HgS (Mercury Sulfide)

### Final Answer:
The three ores concentrated by the froth flotation process are:
1. **Galena** - PbS
2. **Zinc Blende** - ZnS
3. **Cinnabar** - HgS