The properties of nonmetals- nonductile(cannot be turned into wire), dull color, high solubility, poor conductors, brittle(difficult to break) and have a wide range of colors. Compared to the properties of a metal- polished color, conducters of heat and electricity, cannot be dissolved, malleable(can bend). Would you like me to use certain elements to show this?

7 0

3 years ago

What gets reduced in an electrolytic cell made with nickel and copper electrodes?

jekas [21]

Answer:

D. Ni²⁺

Explanation:

We know at once that the answer cannot be A or C, because Ni and Cu are already in their lowest oxidation states.

The correct answer must be either B or D.

An electrolytic cell is the opposite of a galvanic cell. In the former, the reaction proceeds spontaneously. In the latter, you must force the reaction to occur.

One strategy to solve this problem is:

Look up the standard reduction potentials for the half reaction·
Figure out the spontaneous direction.
Write the equation in the reverse direction.

1. Standard reduction potentials

E°/V

Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419

Ni²⁺ + 2e⁻ ⟶ Ni; -0.257

2. Galvanic Cell

We reverse the direction of the more negative half cell and add.

E°/V

Ni ⟶ Ni²⁺ + 2e⁻; 0.257

Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419

Ni + Cu²⁺ ⟶ Cu + Ni²⁺; 0.599

This is the spontaneous direction.

Cu²⁺ is reduced to Cu.

3. Electrochemical cell

E°/V

Ni²⁺ + 2e⁻ ⟶ Ni; -0.257

Cu ⟶ Cu²⁺ + 2e⁻; -0.3419

Cu + Ni²⁺ ⟶ Ni + Cu²⁺; -0.599

This is the non-spontaneous direction.

Ni²⁺ is reduced to Ni in the electrolytic cell.

8 0

2 years ago

Suppose 11.4g of ammonium chloride is dissolved in 250 ml of a 0.3M aqueous solution of potassium carbonate. Calculate the final

Sindrei [870]

Answer:

The molarity of the final ammonium cation is 0.252M

Explanation:

Step 1: Data given

Mass of ammonium chloride (NH4Cl) = 11.4 grams

Volume of 0.3 M aqueous solution of potassium carbonate (K2CO3) = 250 mL = 0.250L

Step 2: The balanced equation

2NH4Cl + K2CO3 → 2KCl + (NH4)2CO3

Step 3: Calculate moles of (NH4)Cl

moles (NH4)Cl = 11.4 grams /53.49 g/mol

Moles (NH4)Cl = 0.213 moles

Step 4: Calculate moles of K2CO3

Moles K2CO3 = Molarity * Volume

Moles K2CO3 = 0.3M * 0.250 L = 0.075 moles

Step 5: Calculate moles (NH4)Cl at the equilibrium

For 2 moles (NH4)Cl consumed, we need 1 mole of K2CO3 to produce 2 KCl and 1 mole of (NH4)2CO3

(NH4)2CO3l will dissolve in 2NH4+ + CO32-

Moles (NH4)2Cl = 0.213 moles - 2*0.075 = 0.063 moles

Moles NH4+ = moles (NH4)Cl = 0.063 moles

Step 6: Calculate Molarity of NH4+

Molarity = Moles / volume

Molarity of NH4+ = 0.063 moles / 0.250 L

Molarity of NH4+ = 0.252 M

The molarity of the final ammonium cation is 0.252M

5 0

3 years ago

At PO2 = 40 mm Hg, which statement about the saturation of either myoglobin (Mb) or hemoglobin (Hb) is true? At PO2 = 40 mm Hg,

Damm [24]

Answer:

At this partial pressure of oxygen, Mb would be almost completely saturated but Hb would not.

Explanation:

The oxygen saturation curves for Mb and Hb are quite different. The curve for Mb is hyperbolic while that for Hb is sigmoidal.

Mb reaches oxygen saturation before Hb.

Thus, at a partial pressure of 40 mmHg, Mb is almost completely saturated but Hb is not.

4 0

3 years ago