how do i name the ionic compound bythis formula (NH4)2Cr2O7
ammonium dichromate
To name the ionic compound (NH4)2Cr2O7 using its formula, you need to determine the names of each individual ion and then combine them accordingly.
Here's the step-by-step process:
1. Break the formula down into its component ions:
- (NH4)2: This is the ammonium ion (NH4+).
- Cr2O7: This is the chromate ion (Cr2O72-).
2. Determine the name of the first ion, (NH4)+:
- The ammonium ion consists of a nitrogen atom bonded to four hydrogen atoms: NH4+.
- Its name is "ammonium."
3. Determine the name of the second ion, (Cr2O7)2-:
- The chromate ion consists of two chromium atoms bonded to seven oxygen atoms: Cr2O7^2-.
- Its name is "chromate."
4. Combine the names of the ions:
- Start with the name of the first ion, "ammonium."
- Add the name of the second ion, "chromate."
- Therefore, the name of the compound is "ammonium chromate."
Note: In certain cases, ionic compounds may require Roman numerals to indicate the charge on the metal ion. However, in the case of (NH4)2Cr2O7, the ammonium ion (NH4+) does not require a Roman numeral since the charge is always +1. The Roman numerals are typically used for transition metals that can form different charged ions.