Chem Final ExamWhich of the following are factors that affect the rate at which a solute dissolves in a solvent?
Which of the four statements are true? 1. Acids increase the concentration of hydrogen ions in solution. 2. Acids increase the concentration of hydroxide ions in solution. 3. Acids increase the pH of a solution. 4.Acids react with magnesium to produce hydrogen gas.
1 and 4
To calculate the molarity of a solution when the solute is given in grams and the volume of the solution is given in milliliters, you must first:
Convert grams to moles, and convert volume of solution in milliliters to liters
Which observation(s) reflect(s) colligative properties? (I) A 0.5 m NaBr solution has a higher vapor pressure than a 0.5 m BaCl2 solution. (II) A 0.5 m NaOH solution freezes at a lower temperature than pure water. (III) Pure water freezes at a higher temperature than pure methanol.
I and II
Which of the following are true about how temperature affects the rate of reaction? I heating causes the particles of the reactants to move more quickly II lowering the temperature will raise the energy level of the particles III increasing the temperature results in more collisions between the particles
I and III
Equal amounts of heat are absorbed by 100g samples of various solid metals with differing specific heat values. Which of the following statements is true regarding metals and their specific heat values?
The metal with the greatest specific heat will undergo the smallest change in temperature.
When performing a dilution, the stock solution always has _______ molarity (M) than the final solution.
a higher
A compound with water molecules attached is called:
a hydrate
Which one reacts with metals?
acids
Who's law states equal volumes of gases contain equal numbers of particles.
avogadros
Which one is slippery?
base
Who's law states the pressure of the gas is inversely proportional to its volume.
boyles
Who's law states the volume of a gas is directly proportional to its temperature.
charles
Rock salt is used when making ice cream because it depresses the freezing point of the ice. The more salt you add, the lower the freezing point. This is an example of...
colligative property
Which mixture does not separate on standing and has the Tyndall effect?
colloid
Who's law states the sum of the partial pressures of gases in a mixture is equal to the total pressure of the mixture.
daltons
Which is not an operational definition of a base?
decreases the hydrogen ion concentration
Which are colloids?
does not separate but has Tyndall effect, shaving cream
Any substance containing free ions that make a solution conduct electricity is called a/an
electrolyte
The _________ is the simplified formula for a molecular compound.
empirical formula
Which one of the following processes produces a decrease in the entropy of the system?
freezing water to form ice
Which are suspensions?
has particles that are too large to remain mixed, settles out
Which are solutions?
homogeneous, no tyndall effect, has particles that are the size of ions or molecules, kool aid
Two liquids that can be mixed together but separate shortly after are:
immiscible
"Molarity" is described as...
moles of solute/liters of solution
The coefficients in a chemical equation represent the
relative numbers of moles of reactants and products.
A _____ contains the maximum amount of dissolved solute for a given amount of solvent.
saturated
Which of the following are factors that affect the rate at which a solute dissolves in a solvent?
size of solute particles, temp of solvent, and stirring
A solution is made by dissolving some salt in a beaker of water. The salt is referred to as the
solute
A pH of 2 represents a ________________.
strong acid
Which of these factors would affect the solubility of sodium sulfate?
temperature and surface area
When ___________ is held constant, the pressure and volume of a gas are __________ proportional
temperature, inversely
What is actual yield?
value obtained from the experiment
Which change in state requires that energy be added to the substance?
vaporization