Chemistry Answers

If 1.25 g of sodium carbonate was dissolved in water and the solution titrated with 22.7 ml of hydrochloric acid to a medal orange end point, calculate (i) the molarity and (ii) the percent by mass (density of sution = 1.02 g/ml) of the hydrochloric acid solution

Calculate the molar concentration of each of the following:

a. 6.0 N sulfuric acid (in reactions that replace both hydrogens)

b. 3.5 N potassium hydroxide

c. 4.0 N phosphoric acid (in reactions that replace two hydrogen ions)

d. 6.2 N sodium hydroxide

1. Consider a buffer solution containing an acid with a pKa of 2.3 and an acid concentration that is one-fourth the concentration of the conjugate base. What is the pH of the solution?

2. Calculate the pH of a buffer containing 0.1 M sodium acetate and 0.2 M acetic acid (pKa= 4.76).

3. The pH of the given solution of lactic acid and lactate is 4.30. Calculate the pKa of lactic acid, when the concentration of lactic acid and lactate are 0.020 M and 0.073 M respectively.

it requires 2 sticks of butter to make a batch of 20 cookies. How much butter will it take to make 150 cookies.

1.Given the K values at 25°C, predict the extent of each reaction by indicating whether it is reactant-favored or product-favoured.

N2(g) + 3H2(g)2NH3(g)

K=3.5 ×10^8

CaCO3(s) Ca^+2(aq) + CO3 ^-2, (aq)

K= 3.8 x 10^-9

S(s) + 02(g) ----><------SO2(g)

K=4.2×10^52

AgCl(s) Ag^+1(aq) + Cl^-1(aq)

K=10^-10

Whatever the solvent used, the solution should be topped-up to its final volume using water. True or False?