Question

4 multiple choice 1 point why is water considered the universal solvent? salt atoms change into water water molecules break apart into atoms salt forms a new compound with water water molecules surround and separate salt ions 5 multiple choice 1 point which of the following liquids would heat up the slowest under a constant energy source? water vinegar oil alcohol 6 multiple choice 1 point water helps regulate earths climate because: it can store large amounts of heat energy without major temperature changes. it doesnt freeze easily. it evaporates quickly. it refelcts sunlight.

Explanation:

• Question 4: Water is a polar molecule. When salt (an ionic compound) is added to water, the polar water molecules surround the positive and negative ions of the salt (through ion - dipole interactions), separating them. This property of water (its polarity and ability to interact with a wide variety of solutes) makes it a good solvent. Salt atoms do not change into water (atoms are conserved in physical processes like dissolution). Water molecules do not break apart into atoms during dissolution of salt. Salt dissociates (separates into ions) in water, it does not form a new compound (a chemical reaction to form a new compound would involve bond - making in a different way than simple dissociation).
• Question 5: Water has a high specific heat capacity (\(c = 4.18\space J/g^{\circ}C\)). Specific heat capacity is the amount of heat energy required to raise the temperature of 1 gram of a substance by \(1^{\circ}C\). Vinegar (acetic acid solution), oil (hydrocarbon - based), and alcohol (e.g., ethanol) have lower specific heat capacities than water. Using the formula \(Q = mc\Delta T\) (where \(Q\) is heat energy, \(m\) is mass, \(c\) is specific heat capacity, and \(\Delta T\) is the change in temperature), for a given \(Q\) (constant energy source) and \(m\) (assuming same mass), \(\Delta T=\frac{Q}{mc}\). Since \(c_{water}\) is the highest among the given liquids, \(\Delta T\) (temperature change) for water will be the lowest, meaning it heats up the slowest.
• Question 6: Water has a high specific heat capacity. This means it can absorb or release a large amount of heat energy (\(Q = mc\Delta T\)) with only a small change in temperature (\(\Delta T\)). So, it acts as a temperature buffer. Water does freeze at \(0^{\circ}C\) (which is not a very high temperature, so the statement “it doesn't freeze easily” is not the main reason for climate regulation). Water does evaporate, but evaporation is more related to phase change and cooling of the local surface (not the main reason for Earth - scale climate regulation). Water does reflect some sunlight (albedo), but its high specific heat capacity is the primary reason for climate regulation.

Answer:

• Question 4: Water molecules surround and separate salt ions
• Question 5: water
• Question 6: It can store large amounts of heat energy without major temperature changes.