States Of Matter
Which statement correctly describes the movement of particles in a solid?
A student writes: “When ice melts, the water particles get bigger.” Which correction should be made to this statement?
What is the name of the change of state in which a solid converts directly into a gas without passing through the liquid state?
A student claims that evaporation and boiling are the same process. Which statement correctly distinguishes between them?
Bromine vapour is placed in a gas jar below a gas jar of air. Over several minutes, the brown colour gradually spreads upward into the air jar. Which explanation is correct?
Hydrogen chloride gas (relative molecular mass 36.5) and bromine vapour (relative molecular mass 160) are released simultaneously at the same temperature. Which statement correctly predicts and explains the outcome?
When potassium manganate(VII) is added to water and the solution is repeatedly diluted, the solution becomes paler but never becomes completely colourless. Which explanation is correct?
Which row correctly identifies the solvent, solute, and solution when sugar dissolves in tea?
A concentrated solution of sodium chloride is prepared at 25 °C. A student adds more sodium chloride and it dissolves completely. What can be concluded about the original solution?
Calculate the solubility of potassium chloride if 14.0 g dissolves in 40 g of water at 50 °C.
A student dissolves 9.0 g of copper sulfate in 25 g of water at 60 °C to form a saturated solution. What is the solubility of copper sulfate at 60 °C?
The solubility of substance Y at 70 °C is 80 g per 100 g of water, and at 25 °C it is 35 g per 100 g of water. A saturated solution is prepared at 70 °C using 150 g of water and then cooled to 25 °C. Calculate the mass of crystals that form.
On a solubility curve, a data point lies below the curve for substance Z at 40 °C. What does this indicate about the solution?
A factory stores a hot, saturated solution of a salt in a tank. During winter, the outside temperature drops significantly overnight, and workers discover solid crystals at the bottom of the tank each morning. Which explanation best accounts for this observation?
In the solubility practical, a student heats water directly with a Bunsen burner instead of using a water bath. Which problem is most likely to affect the accuracy of the results?
In the solubility practical, how does the student determine that the solution has become saturated?
Substance P has a nearly flat solubility curve, while substance Q has a steeply rising solubility curve. A student wants to purify substance Q by recrystallisation. Which statement explains why substance Q is more suitable for purification by recrystallisation than substance P?
The solubility of potassium nitrate at 50 °C is 85 g per 100 g of water. A student prepares a solution by dissolving 42.5 g of potassium nitrate in 50 g of water at 50 °C. Determine whether the solution is saturated, and calculate how much more potassium nitrate could dissolve.