Answer :
Let's work through the process of determining the chemical formulas for the given compounds. Here's a step-by-step solution:
### (a) Mercury(I) Nitrite
1. Identify the ions involved:
- Mercury(I) ion: This is a diatomic ion and is represented as [tex]\( \text{Hg}_2^{2+} \)[/tex].
- Nitrite ion: This is represented as [tex]\( \text{NO}_2^- \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Hg}_2^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{NO}_2^- \)[/tex] is -1.
- To balance the charges, you need two [tex]\( \text{NO}_2^- \)[/tex] ions to cancel out the +2 charge of one [tex]\( \text{Hg}_2^{2+} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for mercury(I) nitrite is [tex]\( \text{Hg}_2(\text{NO}_2)_2 \)[/tex].
### (b) Cesium Sulphide
1. Identify the ions involved:
- Cesium ion: [tex]\( \text{Cs}^+ \)[/tex].
- Sulphide ion: [tex]\( \text{S}^{2-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Cs}^+ \)[/tex] is +1.
- The charge of [tex]\( \text{S}^{2-} \)[/tex] is -2.
- To balance the charges, you need two [tex]\( \text{Cs}^+ \)[/tex] ions to cancel out the -2 charge of one [tex]\( \text{S}^{2-} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for cesium sulphide is [tex]\( \text{Cs}_2\text{S} \)[/tex].
### (c) Calcium Phosphate
1. Identify the ions involved:
- Calcium ion: [tex]\( \text{Ca}^{2+} \)[/tex].
- Phosphate ion: [tex]\( \text{PO}_4^{3-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Ca}^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{PO}_4^{3-} \)[/tex] is -3.
- To balance the charges, you need three [tex]\( \text{Ca}^{2+} \)[/tex] ions (total charge of +6) and two [tex]\( \text{PO}_4^{3-} \)[/tex] ions (total charge of -6).
3. Write the chemical formula:
- The chemical formula for calcium phosphate is [tex]\( \text{Ca}_3(\text{PO}_4)_2 \)[/tex].
### (d) Rubidium Sulphate
1. Identify the ions involved:
- Rubidium ion: [tex]\( \text{Rb}^+ \)[/tex].
- Sulphate ion: [tex]\( \text{SO}_4^{2-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Rb}^+ \)[/tex] is +1.
- The charge of [tex]\( \text{SO}_4^{2-} \)[/tex] is -2.
- To balance the charges, you need two [tex]\( \text{Rb}^+ \)[/tex] ions to cancel out the -2 charge of one [tex]\( \text{SO}_4^{2-} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for rubidium sulphate is [tex]\( \text{Rb}_2\text{SO}_4 \)[/tex].
### (e) Barium Hydride
1. Identify the ions involved:
- Barium ion: [tex]\( \text{Ba}^{2+} \)[/tex].
- Hydride ion: [tex]\( \text{H}^- \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Ba}^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{H}^- \)[/tex] is -1.
- To balance the charges, you need two [tex]\( \text{H}^- \)[/tex] ions to cancel out the +2 charge of one [tex]\( \text{Ba}^{2+} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for barium hydride is [tex]\( \text{BaH}_2 \)[/tex].
Hence, the chemical formulas for the given compounds are:
- (a) Mercury(I) Nitrite: [tex]\( \text{Hg}_2(\text{NO}_2)_2 \)[/tex]
- (b) Cesium Sulphide: [tex]\( \text{Cs}_2\text{S} \)[/tex]
- (c) Calcium Phosphate: [tex]\( \text{Ca}_3(\text{PO}_4)_2 \)[/tex]
- (d) Rubidium Sulphate: [tex]\( \text{Rb}_2\text{SO}_4 \)[/tex]
- (e) Barium Hydride: [tex]\( \text{BaH}_2 \)[/tex]
### (a) Mercury(I) Nitrite
1. Identify the ions involved:
- Mercury(I) ion: This is a diatomic ion and is represented as [tex]\( \text{Hg}_2^{2+} \)[/tex].
- Nitrite ion: This is represented as [tex]\( \text{NO}_2^- \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Hg}_2^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{NO}_2^- \)[/tex] is -1.
- To balance the charges, you need two [tex]\( \text{NO}_2^- \)[/tex] ions to cancel out the +2 charge of one [tex]\( \text{Hg}_2^{2+} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for mercury(I) nitrite is [tex]\( \text{Hg}_2(\text{NO}_2)_2 \)[/tex].
### (b) Cesium Sulphide
1. Identify the ions involved:
- Cesium ion: [tex]\( \text{Cs}^+ \)[/tex].
- Sulphide ion: [tex]\( \text{S}^{2-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Cs}^+ \)[/tex] is +1.
- The charge of [tex]\( \text{S}^{2-} \)[/tex] is -2.
- To balance the charges, you need two [tex]\( \text{Cs}^+ \)[/tex] ions to cancel out the -2 charge of one [tex]\( \text{S}^{2-} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for cesium sulphide is [tex]\( \text{Cs}_2\text{S} \)[/tex].
### (c) Calcium Phosphate
1. Identify the ions involved:
- Calcium ion: [tex]\( \text{Ca}^{2+} \)[/tex].
- Phosphate ion: [tex]\( \text{PO}_4^{3-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Ca}^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{PO}_4^{3-} \)[/tex] is -3.
- To balance the charges, you need three [tex]\( \text{Ca}^{2+} \)[/tex] ions (total charge of +6) and two [tex]\( \text{PO}_4^{3-} \)[/tex] ions (total charge of -6).
3. Write the chemical formula:
- The chemical formula for calcium phosphate is [tex]\( \text{Ca}_3(\text{PO}_4)_2 \)[/tex].
### (d) Rubidium Sulphate
1. Identify the ions involved:
- Rubidium ion: [tex]\( \text{Rb}^+ \)[/tex].
- Sulphate ion: [tex]\( \text{SO}_4^{2-} \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Rb}^+ \)[/tex] is +1.
- The charge of [tex]\( \text{SO}_4^{2-} \)[/tex] is -2.
- To balance the charges, you need two [tex]\( \text{Rb}^+ \)[/tex] ions to cancel out the -2 charge of one [tex]\( \text{SO}_4^{2-} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for rubidium sulphate is [tex]\( \text{Rb}_2\text{SO}_4 \)[/tex].
### (e) Barium Hydride
1. Identify the ions involved:
- Barium ion: [tex]\( \text{Ba}^{2+} \)[/tex].
- Hydride ion: [tex]\( \text{H}^- \)[/tex].
2. Balance the charges:
- The charge of [tex]\( \text{Ba}^{2+} \)[/tex] is +2.
- The charge of [tex]\( \text{H}^- \)[/tex] is -1.
- To balance the charges, you need two [tex]\( \text{H}^- \)[/tex] ions to cancel out the +2 charge of one [tex]\( \text{Ba}^{2+} \)[/tex] ion.
3. Write the chemical formula:
- The chemical formula for barium hydride is [tex]\( \text{BaH}_2 \)[/tex].
Hence, the chemical formulas for the given compounds are:
- (a) Mercury(I) Nitrite: [tex]\( \text{Hg}_2(\text{NO}_2)_2 \)[/tex]
- (b) Cesium Sulphide: [tex]\( \text{Cs}_2\text{S} \)[/tex]
- (c) Calcium Phosphate: [tex]\( \text{Ca}_3(\text{PO}_4)_2 \)[/tex]
- (d) Rubidium Sulphate: [tex]\( \text{Rb}_2\text{SO}_4 \)[/tex]
- (e) Barium Hydride: [tex]\( \text{BaH}_2 \)[/tex]
