3. If you wish to make 500.0 mL of 0.150 M HCl solution from 6.00 M HCl stock solution, what volume of the stock would you need? 4) if 50.00 mL of 0.300 M AgNO3 are diluted to 250.0 mL, what is the concentration of the new solution?​

3. 12.5 mL

4. 0.06 M

Explanation:

3. Determination of the volume of stock solution.

Volume of diluted solution (V₂) = 500 mL

Molarity of diluted solution (M₂) = 0.150 M

Molarity of stock solution (M₁) = 6 M

Volume of stock solution needed (V₁) =?

M₁V₁ = M₂V₂

6 × V₁ = 0.150 × 500

6 × V₁ = 75

Divide both side by 6

V₁ = 75 / 6

V₁ = 12.5 mL

Thus, the volume of the stock solution needed is 12.5 mL

4. Determination of the molarity of the diluted solution.

Volume of stock solution (V₁) = 50 mL

Molarity of stock solution (M₁) = 0.3 M

Volume of diluted solution (V₂) = 250 mL

Molarity of diluted solution (M₂) =?

M₁V₁ = M₂V₂

0.3 × 50 = M₂ × 250

15 = M₂ × 250

Divide both side by 250

M₂ = 15 / 250

M₂ = 0.06 M

Thus, the concentration of the diluted solution is 0.06 M

5 moles of Fe.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

Fe₂O₃ + 2Al —> Al₂O₃ + 2Fe

From the balanced equation above,

1 mole of Fe₂O₃ reacted with 2 moles of Al to produced 2 moles of Fe.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

1 mole of Fe₂O₃ reacted with 2 moles of Al.

Therefore, 3 moles of Fe₂O₃ will react with = 3 × 2 = 6 moles of Fe.

From the calculation made above, we can see clearly that a higher amount (i.e 6 moles) of Al than what was given (i.e 5 moles) is needed to react completely with 3 moles of Fe₂O₃.

Therefore, Al is the limiting reactant and Fe₂O₃ is the excess reactant.

Finally, we shall determine the maximum amount of Fe produced.

This can be obtained by using the limiting reactant as illustrated below.

NOTE: The limiting reactant is Al.

From the balanced equation above,

2 moles of Al reacted to produce 2 moles of Fe.

Therefore, 5 moles of Al will also react to produce 5 moles of Fe.

Thus, 5 moles of Fe were obtained from the reaction.