If 4.168 kJ of heat is added to a calorimeter containing 75.40 g of water, the temperature of the water and the calorimeter incr

Explanation:

The scale under her feet exerts an equal force but opposite in direction.

This principle aligns with Newton's third law of motion, which says that "for every action, there is an equal and opposite reaction."

As the girl’s weight presses down on the scale with a force of 42N, the scale responds with an equal upward force in the opposite direction.

The resulting net force is zero, which explains why her weight does not break the scale.

Learn more:

Force

Answer:

Explanation:

Charge of one electron =

The formula for calculating charge is:

Given that: Charge =

Total electrons, n =

Response:

a. 3 Br₂(l) + 6 OH⁻(aq) → 5 Br⁻(aq) + BrO₃⁻(aq) + 3 H₂O

b. Br₂

c. Br₂

Clarification:

Balancing a redox reactionis performed using the ion-electron method.

Step 1: Identify both half-reactions.

Reduction: Br₂(l) → Br⁻(aq)

Oxidation: Br₂(l) → BrO₃⁻(aq)

Step 2: Perform mass balance. This reaction occurs in basic conditions, thus we must add OH⁻ and H₂O as needed.

0.5 Br₂(l) → Br⁻(aq)

6 OH⁻(aq) + 0.5 Br₂(l) → BrO₃⁻(aq) + 3 H₂O

Step 3: Ensure electrical balance by incorporating electrons when necessary.

1 e⁻ + 0.5 Br₂(l) → Br⁻(aq)

6 OH⁻(aq) + 0.5 Br₂(l) → BrO₃⁻(aq) + 3 H₂O + 5 e⁻

Step 4: Scale both half-reactions to ensure the electron counts balance out.

5 × (1 e⁻ + 0.5 Br₂(l) → Br⁻(aq))

1 × (6 OH⁻(aq) + 0.5 Br₂(l) → BrO₃⁻(aq) + 3 H₂O + 5 e⁻)

Step 5: Combine both half-reactions and simplify as appropriate.

5 e⁻ + 3 Br₂(l) + 6 OH⁻(aq) → 5 Br⁻(aq) + BrO₃⁻(aq) + 3 H₂O + 5 e⁻

3 Br₂(l) + 6 OH⁻(aq) → 5 Br⁻(aq) + BrO₃⁻(aq) + 3 H₂O

The species that undergoes reduction is identified as the oxidizer. The species that undergoes oxidation is termed the reducer. In this situation, Br₂ qualifies as both.

Sulfur in the thionyl compound carries a formal charge of +1 and possesses two lone electrons, which constitutes one lone pair.

Additional Explanation

Lewis Structures

To ascertain the formal charge and count of lone pairs, it is crucial to first construct the Lewis structure. The steps to delineate lone pairs are as follows:

1. Calculate the total valence electrons by adding the valence electrons of each atom in the compound.
2. Identify the central atom.
3. Position the remaining atoms around the central atom, connecting each with a single bond. Each bond corresponds to 2 of the total valence electrons shared.
4. Distribute any leftover valence electrons to the terminal atoms, prioritizing one until it reaches an octet, then proceed to the next. If all terminal atoms satisfy the octet rule, remaining electrons go to the central atom.

For thionyl chloride, sulfur serves as the central atom, and the overall valence electron count is:

Cl = 7 × 2 = 14

S = 6

O = 6

Total Valence Electrons = 14 + 6 + 6 = 26 electrons. Following these steps generates the corresponding Lewis structure shown in the attachment.

Having established the Lewis structure, the number of lone pairs on the central atom can be determined. In thionyl chloride, sulfur possesses two unshared electrons, signifying one lone pair.

Formal Charge Assessment

The electron distribution in a molecule is defined through the formal charges on its atoms. A formal charge reflects the disparity between the electrons surrounding an atom in a molecule versus when it is isolated. For molecular stability, formal charges across all atoms need to be minimized.

The formula for formal charge calculation is:

Formal Charge = # valence electrons for isolated atom - (# bonds + non-bonding electrons)

For the thionyl compound, sulfur's formal charge is evaluated using this formula in conjunction with the Lewis Structure:

• Valence Electrons of a Sulfur atom = 6
• Number of bonds surrounding Sulfur = 3
• Number of non-bonding electrons on Sulfur = 2

Formal Charge of S = 6 - (3 + 2)

Formal Charge of S = +1

This indicates that sulfur possesses fewer electrons in the molecule than it would as an isolated atom.

Further Exploration

1. Lewis Structure
2. Valence Electrons

Key Terms: formal charge, lone pairs