General Chemistry Answers

What pressure is required to reduce 64 mL of a gas at standard conditions to 17 mL at a temperature of 29◦C? Answer in units of atm.

Sphere A and B have the same initial positive charge q0. The magnitude of the repulsive electric force between the two spheres is 14.1 N when separated by a distance of 0.03 m. (a) find the initial charge q0. (b) The spheres are then allowed to touch each other and the separated. Find the electric force between them if the radius of sphere A is there times that of sphere B.

Two different atoms have four protons each and the same mass. However , one has a positive charge while the other is neutral. Describe what each atomic structure could be, listing the possible number and location of all subatomic particles.

100.0 mL of a 0.500 M solution of KBr is diluted to 500.0 mL. What is the new concentration of the solution?

5.Balance the equation below and use it to answer the questions that follow:

C₂O₄^2-(aq) + MnO₄^-(aq) + H⁺(aq) = CO₂(g) + Mn²⁺(aq) + H₂O(I)

(I) Which ionic species is an oxidizing agent and which is a reducing agent

(II) Twenty five 25 cm³ of a solution of sodium ethanediote of concentration 0.1 mol dm^-3 were placed in a conical flask. A burrete was filled with patassium manganate (VII) solution of concentration 0.038 mol dm^-3 . Determine the volume of the manganate (VII) solution that would be needed to give the endpoint in the titration.

(III) Assuming that the KMnO₄ was prepared by dissolving 6.94 g of salt in 1 dm³ of solution. Calculate the % purity of KMnO₄

How many mL of water must be added to 250mL of 0.578 M CaCl2 solution to give a 0.349 M solution?

4. Write two equations to depict the amphitropic nature of water.

(b) define the following: (I) pH and (II) pKa

(c).For a reaction between a weak acids and water as shown, prove that pH =pKa -log [acid/base].

HB(acid) + H₂O = H₃O⁺ + B^-

(d) List the factors that affect the solubility of a substances.

(e) Calculate the solubility in grams per litre of silver sulphide if the K_sp of Ag₂S is 6.3 x 10^-50

Using Henderson hasselbalch equation determine concentration of acid and conjugate base in 0.1M phosphate at ph 6.24

1. In the form of table , select from the the following species acids - base conjugate -pairs indicating which is the acid and which is the base.

H_2, O^2- ,HPO₄^2- ,NH₃,OH ^-,H₂O, H₂PO₄^-,H^-,NH₄⁺

2. (a). Arrange the following hydrated cations in order_by of increasing strength as Bronsted - Lowry acids and account for your sequence .

[Na(H₂O)_x ]⁺, [Al(H₂O)_x]³⁺, [Mg(H₂O)_x]²⁺

(b) Which of the under-listed acids is stronger and why ?

(I) CH₂ClCOOH and (II) CH₂COOH

Determine the volume occupied by 2.5 mol of a gas at 18 degrees if the pressure is at 81.8 kPa