Question

the table shows the mass of some elements. find the mass of each compound
Element | mass of an atom (amu) | element | mass of an atom (amu)
Mg 24 Na 23
Cl 35 Br 80
H 1 O 16

Mass of MgCl2: (insert answer)
Mass of NaBr: (insert answer)
Mass of H2O: (insert answer)

Answer 1

To find the mass of each compound, we can use the atomic masses provided and the chemical formulas to calculate the total mass by summing the masses of the constituent elements.

1. **Mass of MgCl₂:**
- Molar mass of Mg: 24 amu
- Molar mass of Cl: 35 amu
- In MgCl₂, there is 1 Mg atom and 2 Cl atoms.
- Total mass = (1 × 24) + (2 × 35) = 24 + 70 = 94 amu

**Mass of MgCl₂: 94 amu**

2. **Mass of NaBr:**
- Molar mass of Na: 23 amu
- Molar mass of Br: 80 amu
- In NaBr, there is 1 Na atom and 1 Br atom.
- Total mass = (1 × 23) + (1 × 80) = 23 + 80 = 103 amu

**Mass of NaBr: 103 amu**

3. **Mass of H₂O:**
- Molar mass of H: 1 amu
- Molar mass of O: 16 amu
- In H₂O, there are 2 H atoms and 1 O atom.
- Total mass = (2 × 1) + (1 × 16) = 2 + 16 = 18 amu

**Mass of H₂O: 18 amu**

Here is the summary:
- **Mass of MgCl₂: 94 amu**
- **Mass of NaBr: 103 amu**
- **Mass of H₂O: 18 amu**