Question
The table shows the chemical formulas and melting points for four compounds.
Table:
Formulas | Melting Point (°C)
CH4 | -182
H2O | 0
MgCI2 | 714
NaBr | 747
What types of bonds formed in each of these compounds, and how does the melting point data support this conclusion?
A. CH4 and H2O must have ionic bonds because they have high melting points, whereas MgCl2 and NaBr must have covalent bonds because they have low melting points.
B. CH4 and H2O must have ionic bonds because they have low melting points, whereas MgCl2 and NaBr must have covalent bonds because they have high melting points.
C. CH4 and H2O must have covalent bonds because they have low melting points, whereas MgCl2 and NaBr must have ionic bonds because they have high melting points.
D. CH4 and H2O must have covalent bonds because they have high melting points, whereas MgCl2 and NaBr must have ionic bonds because they have low melting points.
Table:
Formulas | Melting Point (°C)
CH4 | -182
H2O | 0
MgCI2 | 714
NaBr | 747
What types of bonds formed in each of these compounds, and how does the melting point data support this conclusion?
A. CH4 and H2O must have ionic bonds because they have high melting points, whereas MgCl2 and NaBr must have covalent bonds because they have low melting points.
B. CH4 and H2O must have ionic bonds because they have low melting points, whereas MgCl2 and NaBr must have covalent bonds because they have high melting points.
C. CH4 and H2O must have covalent bonds because they have low melting points, whereas MgCl2 and NaBr must have ionic bonds because they have high melting points.
D. CH4 and H2O must have covalent bonds because they have high melting points, whereas MgCl2 and NaBr must have ionic bonds because they have low melting points.
Answers
GPT-4o mini
The correct answer is **C. CH4 and H2O must have covalent bonds because they have low melting points, whereas MgCl2 and NaBr must have ionic bonds because they have high melting points.**
### Explanation:
1. **CH4 (methane)** and **H2O (water)** have relatively low melting points (-182 °C and 0 °C, respectively). These low melting points indicate that they have weaker forces holding the molecules together, which is characteristic of compounds with covalent bonds. In covalent compounds, the interactions between molecules (such as Van der Waals forces or hydrogen bonding in the case of water) are generally weaker than ionic bonds.
2. **MgCl2 (magnesium chloride)** and **NaBr (sodium bromide)**, on the other hand, have high melting points (714 °C and 747 °C, respectively). High melting points are indicative of strong ionic bonds, which occur in compounds formed by the electrostatic attraction between positively and negatively charged ions. The strong forces of attraction in ionic compounds require much more energy to overcome during melting, resulting in higher melting points.
Therefore, the melting point data support the conclusion that CH4 and H2O have covalent bonds and MgCl2 and NaBr have ionic bonds.
### Explanation:
1. **CH4 (methane)** and **H2O (water)** have relatively low melting points (-182 °C and 0 °C, respectively). These low melting points indicate that they have weaker forces holding the molecules together, which is characteristic of compounds with covalent bonds. In covalent compounds, the interactions between molecules (such as Van der Waals forces or hydrogen bonding in the case of water) are generally weaker than ionic bonds.
2. **MgCl2 (magnesium chloride)** and **NaBr (sodium bromide)**, on the other hand, have high melting points (714 °C and 747 °C, respectively). High melting points are indicative of strong ionic bonds, which occur in compounds formed by the electrostatic attraction between positively and negatively charged ions. The strong forces of attraction in ionic compounds require much more energy to overcome during melting, resulting in higher melting points.
Therefore, the melting point data support the conclusion that CH4 and H2O have covalent bonds and MgCl2 and NaBr have ionic bonds.