For a laboratory investigation some students put a strip of shiny metal into a beaker of blue solution and then stored the beake
r on a shelf
overnight. The next morning, the students recorded observations about the metal and the solution in the box below.
Students' Observations
Exhibit
. The solution is lighter in color,
The volume of solution is the same.
• The metal strip is shiny above the surface of the solution
• The metal strip is not shiny below the surface of the solution.
• The metal strip below the surface of the solution has a dark
coat of flaky material
• When the metal strip is touched, the flaky material falls off.
Based on their observations, can the students correctly conclude that a chemical reaction occurred?
A. No, because the metal strip was still visible
B. Yes, because a new material of a different color formed on part of the metal strip
c. No, because the solution stayed blue
ble solution stayed the same
12 AM
overnight. The next morning, the students recorded observations about the metal and the solution in the box below.
Students' Observations
Exhibit
. The solution is lighter in color,
The volume of solution is the same.
• The metal strip is shiny above the surface of the solution
• The metal strip is not shiny below the surface of the solution.
• The metal strip below the surface of the solution has a dark
coat of flaky material
• When the metal strip is touched, the flaky material falls off.
Based on their observations, can the students correctly conclude that a chemical reaction occurred?
A. No, because the metal strip was still visible
B. Yes, because a new material of a different color formed on part of the metal strip
c. No, because the solution stayed blue
ble solution stayed the same
12 AM
1 answer:
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Answer:
696 h
Explanation:
Let's consider the reduction of Cr³⁺.
Cr³⁺(aq) + 3e⁻ → Cr(s)
We can establish the following relations.
- The molar mass of Cr is 52.0 g/mol.
- 1 mol of Cr is deposited when 3 moles of e⁻ circulate.
- 1 mole of e⁻ has a charge of 96468 c (Faraday's constant).
- 1 A = 1 c/s
- 1 h = 3600 s
<em>How many hours will it take to plate 13.5 kg of chromium onto the cathode if the current passed through the cell is held constant at 30.0 A?</em>
Answer: The concentration of hydroxide ions at this temperature is
Explanation:
When an expression is formed by taking the product of concentration of ions raised to the power of their stoichiometric coefficients in the solution of a salt is known as ionic product.
The ionic product for water is written as:
As
The concentration of hydroxide ions at this temperature is