General Chemistry Answers

A water sample is not alkaline to phenolphthalein however 25ml of the sample on titration required 4.5ml , 0.02N HCL for methyl orange end point. Determine the types and amount of alkalinity present in the sample? (Find P&M, amount of alkalinity)

Calculate the pH of a solution which contains 2.0 x 10-3 M sodium acetate and 3.3 x 10-2 M acetic acid in a liter solution. The pKa is 4.74.

What is the ratio of the salt & acid concentration if the solution has a pH of 4.5 & pKa of 4.76?

Calculate the pH of a solution which contains 3.7 x10−2 mole of HAc & 4.8 x 10−2 mole of Na Ac in a liter of solution containing pka 9.26.

A buffer is prepared using 0.28 M HNO2 and 0.23 M NO2 − . The pKa for HNO2 is 3.34. What is the pH of

this buffer after the addition of 0.05 M HCl?

How would you test for the presence of the following ions in aqueous solution of an unknown salt? kindly provide name of the test and a balanced chemical equation...Ag^2+

The freezing point of benzene is 5.5oC. What is the freezing point of a solution of 5.00 g of naphthalene (C10H8) in 444 g of benzene (Kf of benzene = 4.90oC/m) 

The energy for the following reaction was measured to be -1033.0 kJ/mol.

Mg(g) + 2 Cl(g) → MgCl₂(s).

Using this fact and the data in the table below, calculate the enthalpy (in kJ/mol) required to separate the ions from the lattice for this reaction:

MgCl₂(s) → Mg²⁺(g) + 2Cl⁻(g).

If 190cmcube3 of hydrogen is collected at 26degree celcius and 736mmHg,calculate it volume at S.T.P (standard pressure is 760mmHg

TRUE OR FALSE

1. When solid is heated, the temperature rises until it reaches the melting point temperature.

2. Concentrated means that the amount of solute is relatively high.

3.The alcohol content of hard liquor is given by the term “ABV”, which is defined as twice the percentage by volume of ethanol present.

4. The attractive forces between neighboring particles are called intermolecular forces.

5. The dispersion forces of an element determines to which atom the shared electrons are closer.