envirochem test prep - hydrochemistry

heat capacity

Water's physical properties and ________ play a crucial role in regulating global temperature.

High surface tension

________- ________ allows the formation of water droplets and waves, allows plants to move water (and dissolved nutrients) from their roots to their leaves, and movement of blood through tiny vessels in the bodies of some animals.

what is the importance of waters specific heat capacity in regulating global temp

Water has a high heat capacity, which means it can absorb and store a large amount of heat energy without a significant increase in temperature. This property is important in regulating temperature in various environments, including the Earth's atmosphere and bodies of water

what happens to freezing point and boiling point when pressure increases?

freezing point lowers, and boiling point rises as external pressure is holding molecules closer together so more energy is needed to go from liquid to gas and less energy is needed for a solid form as If water freezes, the it forms a crystalline solid phase with a proper arrangement. Now what happens when pressure increases water molecules cannot be properly arranged, so water cannot freezes at the freezing point at 273K. That means water freezes at below 273K.

what happens to freezing point and boiling point when pressure decreases

freezing and boiling point is directly proportional to the pressure exerted on it. As pressure decreases, the molecules of water require less energy to escape into the air, resulting in a lower boiling point. As pressure decreases, the molecules of water require less energy to break their bonds and form a solid, resulting in a lower freezing point.

how are the physical properties of water influenced by salinity

density increases, freezing point lowers as ions disrupt ordered lattice structure and so freezing point lowers below 0 degrees c. boiling point increases as na and cl ions bind with positive and negative ends of water forming ion-dipole bonds which are stronger than the h bonds holding the water molecules together. because they are stronger, more energy is needed to overcome and so boiling point is raised.

how does density from salinity impact ocean circulation

When seawater becomes more saline, it becomes denser and sinks to the bottom, creating a flow of water

what is the difference between weak and strong acids

weak acids partially dissociate while strong acids fully dissociate

how is acid base and complexation related

Acid-base reactions can influence complexation and Complexation can affect acid-base properties:

**how does** ***molecular diffusion*** **limit gas exchange.**

by slowing down the movement of gases across a membrane due to the random motion of molecules. This can result in a slower rate of gas exchange between two regions with different concentrations of gases.

**Explain why** ***rainwater is naturally acidic*** **and why this is sensitive to temperature.**

rain has a slightly acidic pH because carbon dioxide and water in the air react together to form carbonic acid, a weak acid.

Solubility of gases decreases with an increasing temperature. Therefore, pH of water is likely to decrease (more acidic) in cold water temperatures as there is higher solubility for CO2 and so more co2 can dissolve in water and dissociate, causing more acid and therefore lower pH

1 variable vs 2 variable species diagram

Single-variable diagrams are plots of some species concentration (y-axis) vs. a single independent variable (e.g., pH)

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2 variable diagrams in which the dominant species are plotted in 2 dimensions as a function of 2 independent variables - not just pH but something else as well e.g pe/ph diagram

limitation of single and 2 variable diagram

• Limitation of single variable species diagram is that in real life there are many variables affecting things, not just one

• These 2 variable diagrams are not good at dealing with gases or solids because we have to make assumptions around it

• Limitations of pE-pH diagrams

• • Can’t accurately represent concentrations

• • Can’t accurately represent boundaries for gases and solids (most accurate when dealing with aqueous solutions)