Chemistry Test 1-Solutions and Solubility #5
A chemist dissolved crystals of an unknown substance into water at room temperature. He found that 33 g of the substance can be dissolved into 100 mL of water. What property of the unknown substance was the chemist most likely investigating? its solubility its rate of dissolution its chemical reaction to water its reaction to temperature changes
A.
A student was comparing the solubility of equal amounts of table salt and table sugar at different temperatures.The table below shows the four samples that the student used and the temperature of the water that they were dissolved in. Sample Name Chemical formula Temperature of water (°C) 1 Table sugar C12H22O11 80 2 Table sugar C12H22O11 45 3 Table salt NaCl 55 4 Table salt NaCl 63 Which of the samples most likely had the highest solubility? 1 2 3 4
A.
Which factor increases the rate of dissolution in an unsaturated solution? increasing the temperature decreasing the surface area decreasing the amount of solute increasing the amount of solvent
A.
Which refers to the amount of a solute that will dissolve in a given volume of solvent at a given temperature and pressure? solubility supersaturated dissolution rate concentrated
A. Solubility
A beaker contains a solution. A single solute crystal is added to the solution. Immediately, crystals form in the solution. Which term best describes the solution before the crystal was added? supersaturated unsaturated diluted saturated
A. Supersaturated
A 1-L soda bottle contains dissolved carbon dioxide gas. Which bottle would have the highest concentration of dissolved gas? a bottle that is sealed a bottle that was opened 1 minute ago a bottle that was opened 1 hour ago a bottle that was opened 1 day ago
A. a bottle that is sealed
Which method would increase the solubility of a gas? increasing the pressure stirring the solvent quickly increasing the temperature decreasing the amount of solvent
A. increasing the pressure
Which is true about dissolving a polar substance in water? The solvent particles are all nonpolar molecules. The solute particles are carried into the solution. The solute particles have no attraction for the solvent molecules. The solute particles are very different from the solvent molecules.
B.
Solute crystals are added to a solution until they begin to sink to the bottom of their container. The solution is then heated, and many more solute crystals dissolve. Which term best describes the solution immediately after it was heated? saturated unsaturated concentrated supersaturated
B. Unsaturated
Under which conditions would the solubility of a gas be greatest? high pressure and high temperature high pressure and low temperature low pressure and high temperature low pressure and low temperature
B. high pressure and low temperature
The graph below shows how solubility changes with temperature. mc026-1.jpg Which two solutions have similar solubilities at 40°C? Na2SO4 and NaCl Na2HAsO4 and NaCl Na2HAsO4 and Na2SO4 Ba(NO3)2 and Ce2(SO4)3 • 9H2O
C.
Under which conditions will sugar most likely dissolve fastest in a cup of water? a sugar cube with stirring at 5°C a sugar cube without stirring at 15°C sugar crystals with stirring at 15°C sugar crystals without stirring at 5°C
C.
Which is the second step in the dissolving process? The solute is mixed with the solvent. The solute ions are carried into the solution. The solvent molecules surround the solute particles. The solvent molecules are attracted to the surface of the solute particles.
C.
The graph below shows how solubility changes with temperature. mc022-1.jpg What is the solubility of Na2HAsO4 at 60°C? 20 g/100 mL of water 46 g/100 mL of water 65 g/100 mL of water 70 g/100 mL of water
C. 65 g/100 mL of water
Which is true about the dissolving process in water? Nonpolar solutes dissolve easily in water. Solute molecules surround water molecules. Molecules or ions of a solute spread throughout the water molecules. Water molecules are repelled by solute ions at the surface of the solute.
C. Molecules or ions of a solute spread throughout the water molecules.
The concentration of a solute in a solution is greater than the maximum concentration that is predicted from the solute's solubility. What is the best way to describe this solution? diluted saturated unsaturated supersaturated
D.
A chemist has dissolved a certain substance in water. The chemist knows that more of the substance could be dissolved into the water before it stops dissolving. Therefore, the current solution is _______________________.
unsaturated
