Acid, base, strong electrolyte, weak electrolyte, and nonelectrolyte

Question 1

• Acid: Examples include hydrochloric acid (HCl) and acetic acid (CH3COOH). They are defined as substances that release hydrogen ions (H+) when dissolved in water.
• Base: Examples include sodium hydroxide (NaOH) and ammonia (NH3). Bases are substances that release hydroxide ions (OH-) when dissolved in water.
• Strong electrolyte: An example is sodium chloride (NaCl). It dissociates completely into ions when dissolved in water, resulting in a high conductivity of electricity.
• Weak electrolyte: An example is acetic acid (CH3COOH). It partially dissociates into ions when dissolved in water, resulting in a lower conductivity of electricity compared to strong electrolytes.
• Nonelectrolyte: Examples include glucose (C6H12O6) and ethanol (C2H5OH). They do not dissociate into ions when dissolved in water, resulting in no conductivity of electricity.

Question 2

• Fission: The splitting of a heavy nucleus into two lighter nuclei, accompanied by the release of a large amount of energy. Example: Nuclear power plants use fission reactions, such as the splitting of uranium-235, to generate electricity.
• Fusion: The process of combining two light atomic nuclei to form a heavier nucleus, releasing a large amount of energy. Example: The fusion reaction that powers the sun involves the combination of hydrogen nuclei to form helium.

Question 3

a. Steps of the Scientific Method:

• Make an observation.
• Formulate a question.
• Develop a hypothesis.
• Conduct an experiment.
• Analyze the data.
• Draw conclusions.
• Communicate results.

b. Example scientific study: Observation: Plants grow taller when exposed to different types of music. Question: Does music affect plant growth? Hypothesis: Plants exposed to classical music will grow taller than plants exposed to heavy metal music. Experiment: Set up two groups of plants, one exposed to classical music and the other to heavy metal music. Measure and compare their growth over a period of time. Data Analysis: Measure the height of the plants and analyze the data statistically. Conclusion: Determine if there is a significant difference in plant growth between the classical and heavy metal music groups. Communication: Share the findings through a scientific report or presentation.

Question 4

To calculate the mass of sodium chloride (NaCl) used to create a 100 mL solution at a concentration of 1.5 M:

Step 1: Determine the molar mass of NaCl (58.44 g/mol).

Step 2: Convert the volume of the solution from milliliters (mL) to liters (L): 100 mL = 0.1 L

Step 3: Use the formula: Mass (g) = Concentration (mol/L) x Volume (L) x Molar mass (g/mol)

Mass (g) = 1.5 mol/L x 0.1 L x 58.44 g/mol

Step 4: Calculate the mass: Mass (g) = 0.15 g

Therefore, the mass of sodium chloride used to create a 100 mL solution at a concentration of 1.5 M is 0.15 grams.

Question 5

a. The nitrite ion (NO2-) has one total lone pair.

b. The VSEPR molecular shape of the nitrite ion is bent or V-shaped.

c. Two resonance structures can be drawn from the nitrite ion.

Question 6

To convert the density of table salt from grams per cubic centimeter (g/cm3) to pounds per liter (lb/L):

Step 1: Convert grams to pounds: 2.16 g x (1 lb / 453.592 g) = 0.004756 lb

Step 2: Convert cubic centimeters to liters: 1 cm3 = 0.001 L 0.004756 lb / (1 cm3 x 0.001 L/cm3) = 4.756 lb/L

Therefore, the density of table salt is 4.756 lb/L.

Question 7

a. Calculate the amount of nitrogen monoxide (NO) produced if 0.5 g of ammonia (NH3) is reacted:

Using the balanced equation: 4NH3 + 5O2 -> 4NO + 6H2O

Step 1: Convert the mass of ammonia to moles: 0.5 g NH3 x (1 mol NH3 / 17.03 g NH3) = 0.029 mol NH3

Step 2: Use the mole ratio from the balanced equation: 0.029 mol NH3 x (4 mol NO / 4 mol NH3) = 0.029 mol NO

Step 3: Convert moles of nitrogen monoxide to grams: 0.029 mol NO x (30.01 g NO / 1 mol NO) = 0.87 g NO

Therefore, 0.5 g of ammonia will produce 0.87 g of nitrogen monoxide.

b. Calculate the amount of nitrogen monoxide (NO) produced if 0.5 g of oxygen (O2) is reacted:

Step 1: Convert the mass of oxygen to moles: 0.5 g O2 x (1 mol O2 / 32 g O2) = 0.016 mol O2

Step 2: Use the mole ratio from the balanced equation: 0.016 mol O2 x (4 mol NO / 5 mol O2) = 0.0128 mol NO

Step 3: Convert moles of nitrogen monoxide to grams: 0.0128 mol NO x (30.01 g NO / 1 mol NO) = 0.384 g NO

Therefore, 0.5 g of oxygen will produce 0.384 g of nitrogen monoxide.

c. In comparing (a) and (b), the limiting reactant is ammonia (NH3) because it produces less nitrogen monoxide (0.87 g) compared to oxygen (0.384 g). The limiting reactant is the one that is completely consumed and limits the amount of product formed.

Question 8

• CO2 (g): Dispersion forces (London forces) are present due to temporary fluctuations in electron distribution.
• NaCl(aq): Ion-dipole interactions are present between the ions of NaCl and the polar water molecules.
• OF2 (g): Dispersion forces and dipole-dipole interactions are present. Fluorine is more electronegative than oxygen, creating a polar molecule with partial positive and negative charges.

Question 9

To calculate the final volume of the balloon when the amount of helium increases from 1.5 moles to 9.5 moles:

Step 1: Use the ideal gas law equation: PV = nRT

Step 2: Rearrange the equation to solve for V (volume): V = (nRT) / P

Step 3: Plug in the values: n(initial) = 1.5 moles n(final) = 9.5 moles P = pressure (assumed constant) R = gas constant T = temperature (assumed constant)

Step 4: Calculate the final volume: V(final) = (9.5 moles x RT) / P

Therefore, the final volume of the balloon can be calculated using the ideal gas law equation.

Question 10

To calculate the amount of heat required to convert 5.6 g of the compound C2Cl3F3 from a liquid at 30.0 °C to a gas at 60.5 °C:

Step 1: Calculate the heat required to raise the temperature of the liquid compound: q1 = m x specific heat x ΔT q1 = 5.6 g x 0.91 J/g-K x (60.5 °C – 30.0 °C)

Step 2: Calculate the heat required for phase change (vaporization): q2 = n x ΔHvap n = moles of the compound ΔHvap = heat of vaporization

Step 3: Convert grams to moles: moles = 5.6 g / molar mass

Step 4: Calculate the heat required for vaporization: q2 = moles x ΔHvap

Step 5: Calculate the total heat required: total heat = q1 + q2

Therefore, the amount of heat required to convert 5.6 g of the compound from a liquid at 30.0 °C to a gas at 60.5 °C can be calculated using the specific heat, heat of vaporization, and temperature changes.