General Chemistry Answers

Why don't metals burn?

How many grams are in 50 ml of .0025 moles of Ca(Oh)2

Suppose that 2.50 g of NaCl is required for a certain reaction. If the NaCl is available as a 0.150 molar solution, how many mL of the solution must be used?

For the reaction shown, calculate how many moles of NO2 form when each amount of reactant completely reacts.

2N2O5(g)->4NO2(g)+O2(g)

4.72×103molN2O5

Express your answer using three significant figures.

What is the vapor pressure of an aqueous solution that has a solute mole fraction of 0.300? The vapor pressure of water is 25.756 mmHg at 25 °C.

If 10.0 mL of 2.50 M SrS (aq) is made to react with 25.0 mL of 1.50 M ZnSO4 (aq), how many moles of the excess reactant will be left after the reaction? Express your answer in three significant figures.

A solution is prepared by mixing equal volumes of 0.20M HC₂H₃O₂ and 0.40M NaC₂H₃O₂. Which of the following correctly describes what occurs if a small amount of HCl (aq) or NaOH (aq) is added? Explain

• If NaOH (aq) is added, the pH will increase only slightly because the OH⁻ ions will react with HC₂H₃O₂ molecules.
• If HCl (aq) is added, the pH will decrease only slightly because the H⁺ ions will react with HC₂H₃O₂ molecules.

• If HCl (aq) is added, the pH will increase only slightly because the Cl, −, ions will react with C, 2, H, 3, O, 2, −, ions.
• If NaOH (aq) is added, the pH will decrease only slightly because the OH⁻ ions will react with C₂H₃O₂⁻ ions.

A cell using Zn/Zn⁺²(aq, 1M) and H₂/ H⁺¹(aq, 1M) generates a cell potential of +0.67 V under standard conditions.

A. Write the half-cell reaction at the anode.

B. Write the half-cell reaction at the cathode.

C. Write the electrochemical cell notation.

D. Calculate the standard reduction potential at the anode.

"Standard Redox Reactions"

Using the standard reduction potentials, determine whether the reaction id spontaneous under standard conditions:

A. Cl₂ (g) + 2 i^-1(aq) = 2Cl^-1(aq) + i₂(s)

A cell using Zn/Zn⁺² (aq, 1M) and H2 / H+1 (aq, 1M) generates a cell potential of + 0.67 V under standard conditions.

A. Write the half-cell reaction at the anode.

B. Write the half-cell reaction at the cathode.

C. Write the electrochemical cell notation.

D. Calculate the standard reduction potential at the anode.