1. Regarding solutions and solids, which statement is true?
A. If the solvent is water, the crystal lattice energy of a solid is absorbed.
B. Hydration energy is related to the attractions between solute particles. (My Answer)
C. If the solvent is water, the crystal lattice energy of a solid is released.
D. Hydration energy is related to the attractions between solvent particles.
2. Avogadro’s number gives us the number of
A. atoms in any element or compound.
B. particles in a mole of any element or compound.
C. atoms in an element.(My answer)
D. particles in a sample.
3. A chemical formula containing the simplest whole-number ratio between elements in a
compound is called the _______ formula.
A. derivative C. composition ratio
B. composition D. empirical
4. Which one of the following statements is correct?
A. Solubility of solids and liquids is affected by randomness and temperature.(My answer)
B. Increasing temperature and lowering pressure maximizes the solubility of a gas in a
liquid.
C. Energy has no affect on solubility.
D. When a solid dissolves, the attractive forces are weakened, and entropy decreases.
5. For which of the following must the empirical formula be written with only one subscript?
A. C6H6 C. C2H6 (My answer)
B. C5H12 D. H2O2
6. Regarding electrolytes, all of the following statements are true except for which one?
A. Covalent bonds, such as those of sugar, make weak electrolytes in solution. (My Answer)
B. Ionic compounds often form strong electrolytes when in solution.
C. Ammonia is a weak electrolyte because it produces few mobile ions.
D. Mobile ions formed as a result of dissociation cause solutions to conduct electricity.
7. The equation for an equilibrium reaction is A + B AB. Following Le Chatelier’s
principle, if the concentration of “A” is increased, then
A. stress and equilibrium are not affected.
B. the equilibrium shifts to the left.
C. the eqilibrium shifts to the right.
D. a smaller concentration of products is formed (My Answer)
Please check?!
1. The correct answer is B. Hydration energy is related to the attractions between solute particles. To arrive at this answer, understanding the concepts of solvents, solutes, and hydration energy is necessary. Solvation is the process in which a solute is dissolved in a solvent. When a solute dissolves in a solvent, the solute particles are surrounded by solvent molecules. This process involves hydration energy, which is the energy released or absorbed when solute particles are surrounded by solvent particles. In this context, hydration energy is related to the attractions between solute particles.
2. The correct answer is B. particles in a mole of any element or compound. Avogadro's number is a constant that represents the number of particles in one mole of a substance. It is equal to 6.022 × 10^23 particles per mole. These particles can be atoms, molecules, ions, or any other discrete entities depending on the substance.
3. The correct answer is D. empirical. The empirical formula represents the simplest whole-number ratio between the elements in a compound. It does not provide the actual number of atoms present in the compound but gives the relative ratio. To determine the empirical formula, the percentage composition or mass percent of each element in the compound is required.
4. The correct answer is A. Solubility of solids and liquids is affected by randomness and temperature. Solubility refers to the ability of a substance (solute) to dissolve in another substance (solvent) to form a homogeneous mixture. Solubility can be affected by various factors, including temperature and randomness (or entropy). Generally, increasing temperature can increase the solubility of solutes in a solvent. Randomness or entropy can also affect solubility, as substances tend to dissolve in solvents to achieve a more random distribution of particles.
5. The correct answer is C. C2H6. The empirical formula represents the simplest whole-number ratio between the elements in a compound. In the given options, C2H6 has the simplest ratio of carbon to hydrogen atoms, as it can be simplified to CH3. The other options have larger ratios that cannot be simplified further.
6. The correct answer is A. Covalent bonds, such as those of sugar, make weak electrolytes in solution. Electrolytes are substances that produce ions when dissolved in water, and their ability to conduct electricity in solution depends on the presence of mobile ions. Ionic compounds, which involve the transfer of electrons from one atom to another, often form strong electrolytes as they readily dissociate into ions in solution. Covalent compounds, such as sugar, do not readily dissociate into ions in solution and therefore make weak electrolytes.
7. The correct answer is C. the equilibrium shifts to the right. Le Chatelier's principle states that when a system at equilibrium is subjected to a stress, the equilibrium will shift in a direction that minimizes the effect of the stress. In this case, increasing the concentration of "A" will result in an excess of "A" molecules, causing the equilibrium to shift towards the right to form more product (AB) and consume the excess "A" molecules.
Your answers are mostly correct. Here are the correct answers:
1. B. Hydration energy is related to the attractions between solute particles.
2. B. particles in a mole of any element or compound.
3. D. empirical
4. A. Solubility of solids and liquids is affected by randomness and temperature.
5. C. C2H6
6. A. Covalent bonds, such as those of sugar, make weak electrolytes in solution.
7. C. the equilibrium shifts to the right.
Great job! You got 6 out of 7 correct.