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Answer:
Ionic compounds are made up of positive and negative ions held together by strong electrostatic forces of attraction. To break these ionic bonds, a lot of heat energy is needed. That is why their melting and boiling points are very high. For example, sodium chloride (NaCl) melts at about 800°C, and magnesium oxide (MgO) at 2852°C. These values are much higher than for covalent compounds like sugar or water. Because of these strong forces, ionic compounds stay solid at room temperature and need much higher temperatures to change state.
Answer:
Ionic compounds are easily soluble in water because water is a polar solvent. The water molecules pull apart the ions from the lattice, helping them dissolve. For instance, sodium chloride (NaCl) dissolves quickly in water, forming a clear solution. In contrast, ionic compounds do not dissolve well in kerosene or oil, which are non-polar. If you add NaCl to kerosene, it will not dissolve because kerosene cannot separate the ions like water does. So, ionic compounds are generally only soluble in polar solvents like water.
Answer:
In a solid state, ions in ionic compounds are locked in a rigid structure and cannot move, so they cannot conduct electricity. However, when dissolved in water, the ionic lattice breaks up and ions become free to move. These moving ions act as charge carriers, allowing electric current to pass through the solution. For example, sodium chloride (NaCl) solution conducts electricity, but solid NaCl does not. So, movement of ions is necessary for conductivity, and this only happens in solution or molten state.
Answer:
Ionic compounds are hard because their ions are held tightly in a strong, three-dimensional structure by electrostatic forces. But they are also brittle; when an external force is applied, the layers of ions can shift. This shift brings ions of the same charge close together, causing repulsion and breaking the crystal apart. Hence, instead of bending, ionic solids break easily. For example, common salt (NaCl) will shatter if hit with a hammer.
Answer:
Ionic compounds play a key role in everyday life and industries. Table salt (NaCl) is essential for taste and health. Calcium chloride (CaCl₂) is used for de-icing roads in winter. Copper(II) sulfate (CuSO₄) is used in agriculture as a fungicide. Aluminium oxide (Al₂O₃), an ionic compound, is used to make aluminium metal in factories. These examples show that the unique properties of ionic compounds make them vital for food, health, agriculture, and manufacturing processes.
Answer:
To test conductivity, set up an electric circuit with a bulb and graphite electrodes. Test each substance in solid form and then in water solution.
For solids, neither sugar, sodium chloride, nor potassium nitrate will conduct electricity—the bulb stays off—since none of their solid forms have free-moving ions.
For solution, sugar solution also does not conduct, but sodium chloride and potassium nitrate solutions will make the bulb glow, showing that only ionic substances conduct electricity when dissolved. This is because their ions become free to move in water, while sugar (a covalent compound) remains as neutral molecules.
Answer:
Ionic compounds do not conduct electricity when solid because their ions are fixed in place and cannot move. But when they are melted or dissolved in water, ions are free to move, giving rise to conductivity. For example, sodium chloride melts and starts conducting electricity.
Covalent compounds, like sugar or ethanol, do not form ions in water; instead, they dissolve as whole molecules. Because there are no free ions in their solutions, even in water, such solutions do not conduct electricity. This explains why a sugar solution is non-conductive, in contrast to a salt solution.
Answer:
The plant should select sodium chloride (NaCl). This is because sodium chloride dissolves well in water and produces ions that move freely, enabling it to conduct electricity in solution.
Barium sulfate is practically insoluble in water, so it cannot provide enough ions to conduct current.
Kerosene is a covalent compound and non-polar; it does not form ions in solution or conduct electricity.
Therefore, sodium chloride is the best option among the three for electrical conductivity in solution.
Answer:
The statement is not correct. Most ionic compounds are soluble in water, but there are exceptions. For instance, sodium chloride (NaCl) and potassium nitrate (KNO₃) dissolve easily in water.
However, some ionic compounds like barium sulfate (BaSO₄) or lead(II) chloride (PbCl₂) are only sparingly soluble or nearly insoluble in water. The difference is due to the strength of attraction between ions in some lattices, making it hard for water to pull the ions apart. So, while many are soluble, not all ionic compounds behave the same way.
Answer:
Magnesium oxide (MgO) has a very high melting point (about 2852°C), thanks to the strong attraction between its Mg²⁺ and O²⁻ ions. This property makes MgO suitable for high-temperature uses, such as lining furnaces and kilns in industries. It can withstand extreme heat without melting or breaking down, which is crucial in making ceramics, refractories, and insulation. This durability ensures safety and efficiency in melting metals or other substances that need high heat for processing.