Janice is given a mixture of alcohol and water. The teacher tells her that she can use temperature to separate these compounds.

(c) Cu + S → CuS is classified as a redox reaction

Explanation:

The following reactions are presented:

(a) K₂CrO₄ + BaCl₂ → BaCrO₄ + 2 KCl

(b) Pb²⁺ + 2 Br⁻ → PbBr₂

(c) Cu + S → CuS

Reaction (c) represents a redox reaction, as the oxidation states of the elements are changing. In this case:

Cu + S → CuS

In its elemental form, Cu has an oxidation state of 0, while in CuS (copper sulfide), its oxidation state changes to +2.

Similarly, S in its elemental form has an oxidation state of 0 and is -2 in CuS (copper sulfide).

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redox reactions

Yasir wished to explore how sleep relates to room color. He conducted necessary preliminary research and formed a hypothesis suggesting individuals doze off faster in blue-painted rooms compared to those painted in yellow. Yasir surveyed several individuals about their color preference—yellow or blue—and utilized their feedback to assess the validity of his hypothesis. However, he did not conduct an actual experiment to examine the impact of room color on sleep, and he failed to clearly define the variables that should have been part of his experiment.

Hence, the correct answer would be,

An experiment that directly tests the hypothesis

Variables to be tested by an experiment

Answer:

The reaction will proceed in the forward direction, resulting in the reduction of NiO to Ni

Explanation:

Step 1: Provided data

Kp = 6.0 * 10²

Pressure of CO = 150 torr

Total pressure remains under 760 torr

Step 2: The balanced reaction equation:

NiO(s) + CO(g) ⇆ Ni(s) + CO2(g)

Step 3: Determine P(CO) and P(CO2)

For this equilibrium, the Kp expression is:

Kp = P(CO2)/P(CO) = 6.0*10^2

Given that NiO and Ni are solids, they do not affect the Kp

⇒ with P(CO) = 150 torr

⇒ P(CO) = 760 - 150 = 610 torr

Step 4: Calculate the reaction quotient

Q = 610/150 = 4.1

Since Q is significantly less than Kp, there are more reactants than products. Some reactants will convert into products, driving the reaction rightward.

Thus, the reaction will proceed forward, leading to the reduction of NiO to Ni.

Density is calculated as Mass divided by Volume.

Volume can also be expressed as Mass divided by Density.

Volume becomes 2 divided by 128.

This results in Volume equal to 1/64.

Therefore, each side measures 4 cm.