What is the formula and name of the compound formed between Mg and P? Select one: – Mg3P2; Tri Magnesium Di Phosphide – Mg3P2; Magnesium Phosphide – Mg2P3; Magnesium (II) Phosphide – Mg2P3; Magnesium Phosphide Question 20 Not yet answered Marked out of 1.00 Flag question The mass of 1 molecule of HF in grams is 20.01. Select one: – True
The Correct Answer and Explanation is:
Correct Answer:
Mg₃P₂; Magnesium Phosphide
Explanation:
When magnesium (Mg) and phosphorus (P) combine to form a compound, they follow the rules of ionic bonding. Here’s how we determine the correct formula and name:
1. Determine the charges of the ions:
- Magnesium (Mg) is an alkaline earth metal found in group 2 of the periodic table. It tends to lose two electrons to achieve a stable electron configuration, forming a Mg²⁺ ion.
- Phosphorus (P) is a nonmetal found in group 15. It tends to gain three electrons to complete its valence shell, forming a P³⁻ ion.
2. Balance the charges:
To create a neutral compound, the total positive charge must equal the total negative charge. The smallest common multiple of 2 (from Mg²⁺) and 3 (from P³⁻) is 6.
- To get a +6 charge from magnesium, you need three Mg²⁺ ions (3 × +2 = +6).
- To get a –6 charge from phosphorus, you need two P³⁻ ions (2 × –3 = –6).
Thus, the correct formula is Mg₃P₂.
3. Naming the compound:
In naming ionic compounds:
- The metal (Mg) keeps its name: Magnesium.
- The nonmetal (P) takes the suffix “–ide,” becoming Phosphide.
- No prefixes (like “tri” or “di”) are used in naming binary ionic compounds.
So, the correct name is Magnesium Phosphide, and not “Tri Magnesium Di Phosphide.”
Second Part:
The statement “The mass of 1 molecule of HF in grams is 20.01” is FALSE.
Here’s why:
20.01 grams is the molar mass of hydrogen fluoride (HF), not the mass of a single molecule.
- The molar mass is the mass of 1 mole (6.022 × 10²³ molecules) of HF.
- To find the mass of one molecule, divide the molar mass by Avogadro’s number:
20.01 g/mol6.022×1023≈3.32×10−23 grams\frac{20.01 \text{ g/mol}}{6.022 \times 10^{23}} \approx 3.32 \times 10^{-23} \text{ grams}6.022×102320.01 g/mol≈3.32×10−23 grams
So, one molecule of HF weighs only about 3.32 × 10⁻²³ grams, not 20.01 grams.
Final Answers:
- Compound: Mg₃P₂; Name: Magnesium Phosphide
- HF molecule mass statement: False
