A solution of NaNO₃ that contains 120 g of solute dissolved in 100 g of H₂O at 50°C is best described as

A solution of NaNO₃ with 120 g of solute in 100 g of H₂O at 50°C is best described as **supersaturated** since it exceeds the solubility limit of 114 g.

To determine how a solution of NaNO₃ that contains 120 g of solute dissolved in 100 g of H₂O at 50°C is best described, we need to **compare the given concentration to the solubility data** of NaNO₃ in water at 50°C. Generally, solubility data for NaNO₃ in water at 50°C indicate that the solubility is around 114 g of NaNO₃ in 100 g of H₂O. Given the solubility: $$ \text{Solubility of NaNO}_3 \text{ at 50°C} = 114 \, \text{g per 100 g of H}_2\text{O} $$ **Given solution**: $$ \text{NaNO}_3 = 120 \, \text{g} $$ $$ \text{H}_2\text{O} = 100 \, \text{g} $$ ### Determination - A solution is **unsaturated** if the amount of solute is less than the solubility limit. - A solution is **saturated** if it contains the maximum amount of solute that can be dissolved at that temperature. - A solution is **supersaturated** if it contains more solute than the solubility limit, achieved often by changing conditions like temperature and then bringing it back. - A solution is **concentrated** if it has a large amount of solute, but this is relative without specific thresholds. Since the given amount of NaNO₃ (120 g) **exceeds** the solubility of NaNO₃ (114 g) at 50°C: $$ 120 \, \text{g} > 114 \, \text{g} $$ Hence, this solution is best described as **supersaturated**.

15 Aug, 2024

· Chemistry

Unsaturated
Saturated
Supersaturated
Concentrated

Short Answer

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Long Explanation

Explanation

To determine how a solution of NaNO₃ that contains 120 g of solute dissolved in 100 g of H₂O at 50°C is best described, we need to compare the given concentration to the solubility data of NaNO₃ in water at 50°C.

Generally, solubility data for NaNO₃ in water at 50°C indicate that the solubility is around 114 g of NaNO₃ in 100 g of H₂O.

Given the solubility:

\text{Solubility of NaNO}_3 \text{ at 50°C} = 114 \, \text{g per 100 g of H}_2\text{O}

Given solution:

\text{NaNO}_3 = 120 \, \text{g}

\text{H}_2\text{O} = 100 \, \text{g}

Determination

A solution is unsaturated if the amount of solute is less than the solubility limit.
A solution is saturated if it contains the maximum amount of solute that can be dissolved at that temperature.
A solution is supersaturated if it contains more solute than the solubility limit, achieved often by changing conditions like temperature and then bringing it back.
A solution is concentrated if it has a large amount of solute, but this is relative without specific thresholds.

Since the given amount of NaNO₃ (120 g) exceeds the solubility of NaNO₃ (114 g) at 50°C:

120 \, \text{g} > 114 \, \text{g}

Hence, this solution is best described as supersaturated.

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Johnathan Clark

Chemistry Content Writer at Math AI

Johnathan Clark, with a Master's in Chemistry from the University of São Paulo, is a young high school chemistry teacher and part-time contract writer. His engaging classroom experiments translate into compelling written content that makes chemistry exciting and practical.

chemistry

Concept

Solubility

Understanding Solubility

Solubility is a fundamental concept in chemistry that describes how much of a solute can dissolve in a given amount of solvent at a specified temperature and pressure. It quantifies the extent to which a substance (solute) can dissolve in a liquid (solvent) to form a homogeneous mixture, called a solution.

Key Factors Affecting Solubility

Several factors influence solubility, including:

Temperature: Generally, solubility increases with temperature for most solid solutes in liquid solvents. However, the solubility of gases in liquids typically decreases as temperature rises.
Pressure: This mainly affects the solubility of gases. According to Henry's Law, the solubility of a gas in a liquid is directly proportional to the pressure of that gas above the liquid.
Nature of Solute and Solvent: "Like dissolves like" is a rule of thumb. Polar solutes are more soluble in polar solvents, and non-polar solutes are more soluble in non-polar solvents.

Solubility Product Constant (K_sp)

For ionic compounds, the solubility product constant, $K_{sp}$ , is used to express solubility. It is the equilibrium constant for a solid that dissolves in an aqueous solution. The general expression for the dissociation of an ionic compound can be written as:

\text{AB}_{(s)} \leftrightarrow \text{A}^{+}_{(aq)} + \text{B}^{-}_{(aq)}

And the solubility product constant $K_{sp}$ is given by:

K_{sp} = [\text{A}^{+}] \cdot [\text{B}^{-}]

For a more complex compound like $A_m B_n$ , which dissociates as:

A_m B_n \leftrightarrow mA^{n+} + nB^{m-}

The solubility product constant will be:

K_{sp} = [A^{n+}]^m \cdot [B^{m-}]^n

Practical Applications

Medical Field: Understanding solubility is crucial for the formulation of drugs. The efficacy of many medications depends on their solubility in bodily fluids.
Environmental Science: Solubility principles help in assessing the dispersion of pollutants in water bodies.
Chemical Engineering: Designing processes like crystallization, extraction, and purification relies heavily on solubility data.

Measuring Solubility

Solubility measurements involve determining the maximum amount of solute that can dissolve in a solvent at equilibrium. Common methods include:

Gravimetric Analysis: Through mass measurements of the remaining undissolved solute.
Spectroscopic Methods: Using light absorption or emission to assess concentration.
Conductometric Methods: Based on the electrical conductivity changes in the solution.

Understanding and applying the principles of solubility enables chemists and scientists to predict how substances interact in various environments and under different conditions. This knowledge is pivotal in fields ranging from pharmaceuticals to environmental management.

Concept

Saturation Point

Explanation

The saturation point in solutions refers to the maximum amount of solute that can be dissolved in a solvent at a specific temperature and pressure. Beyond this point, any additional solute will remain undissolved in the solution.

At the saturation point, the solution is said to be in a state of equilibrium where the rate of dissolution of the solute is equal to the rate of precipitation of the solute.

Key Concepts

1. Solute and Solvent:

Solute: The substance being dissolved (e.g., salt).
Solvent: The substance in which the solute is dissolved (e.g., water).

2. Temperature and Pressure:

The saturation point is highly dependent on temperature and pressure. Generally, the solubility of solids in liquids increases with temperature.
For gases, the solubility typically decreases as the temperature increases and increases with pressure (Henry's Law).

Mathematical Representation

The relationship for gases is often represented using Henry's law:

C = k_H \cdot P

$C$ is the concentration of the gas in the liquid.
$k_H$ is Henry's law constant.
$P$ is the partial pressure of the gas above the liquid.

For a solute in a liquid, the saturation point can be quantified using the solubility product constant $K_{sp}$ :

K_{sp} = [A^+]^m \cdot [B^-]^n

$[A^+]$ and $[B^-]$ are the molar concentrations of the ions from the solute.
$m$ and $n$ are the stoichiometric coefficients of the dissociated ions.

Practical Implications

Crystallization: When a solution exceeds its saturation point, excess solute tends to form crystals.
Supersaturation: Sometimes solutions can temporarily hold more solute than the saturation point, a state known as supersaturation. This condition is highly unstable and can lead to rapid crystallization.

Conclusion

Understanding the saturation point is crucial for various applications in chemistry, biology, and industrial processes. It helps in predicting how much solute can be dissolved in a solvent under given conditions and what changes might trigger crystallization or precipitation.