General Chemistry Answers

A solution containing 4.50 g of a non-electrolyte (i=1) dissolved in 125 g of water freezes at -0.372ºC. Calculate the molar mass of the solute.

Step 1: First compute the molality of the freezing point equation.

Step 2. Then, from the definition of molality, compute the number of moles solute, n(solute), in the sample.

Step 3. Solve for the molar mass

Write an essay on the topic “When are colligative properties considered beneficial to life?”

a)

An increase in the ionisation of a molecule in a GI environment will usually

increase its solubility. Valproic acid is an oral dosage form used in epilepsy and

has a pKa of 4.8. With the stomach pH at 2.0 and the ileum at pH 6.8, which area

of the GIT will Valproic acid be more soluble.

b)

You are required to manufacture 1L of 50mM pH 7.0 phosphate buffer that could be

used for an injectable formulation of valproic acid. The Ka of dihydrogen phosphate is

6.3x10

-8

and the RMM of potassium dihydrogen phosphate and dipotassium

hydrogen phosphate are 136 and 174 respectively.

I.

Calculate the pKa of dihydrogen phosphate.

II.

What is the ratio between the conjugate base and the acid to be used?

III.

Calculate the mass of anhydrous potassium dihydrogen phosphate and

dipotassium hydrogen phosphate with RMM of 136 and 174, and

concentrations of 30.5 and 19.5 mmol respectively.

  Anhydrous copper(II) sulfate is difficult to dry completely. What mass of copper(II) sulfate would remain after removing 90% of the water from 250. g of CuSO₄×5H₂O? 

Anhydrous copper(II) sulfate is difficult to dry completely. What mass of copper(II) sulfate would remain after removing 90% of the water from 250. g of CuSO₄×5H₂O? 

How to perform a potency test or concentration test of iodine (i2) on a 1L lugol's solution of iodine.

A commercial pesticide Formulation contains 1.0 g deltametrin in 1L solution. What is it's concentration ppm

Thermochemical equation for One mole ammonium nitrate (NH4NO3) dissolves in water to produce aqueous

ammonium ions and nitrate ions accompanied by the absorption of 28.1 kJ of hea

Calculate the amount of heat released during the combustion of

a. 0.75 mole of C₃H₆O 

b. 120g of C₃H₆O 

Different the two types of catalyst through an illustration.