Chapter 11, Problem 2P

4.(a) Aqueous 50.5 % (w/w) sodium hydroxide has a density of 1.53 g cm–3. Calculate the concentration of this solution in mol dm–3.                                                                             (b) What volume of 50.5 % (w/w) aqueous sodium hydroxide is required to prepare 500 cm3 of 0.100 mol dm–3 stock NaOH? [Start with your answer to 4(a)]

Calculate the value of the equilibrium constant, Ke , for the reaction Q(g)+X(g) = 2 M(g)+N(g) given that M(g) Z(g) 6 R(g) = 2 N(g) + 4 Z(g) 3 X(g) + 3 Q(g) 9R(g) Kei 3.59 Kc2 0.567 Kc3 = 13.8 K. =

Give the definition of the inductive effect. What is the reason for its appearance in the molecule? Show the effect of the inductive effect in molecules: bromoethane CH3CH3Br; ethanol CH3CH2OH; fluoroethane CH3CH2F.

A sample of silicone tetrachloride is contaminated by carbon tetrachloride. 20cm3 of distilled water is added to 3.0g of the sample and stirred thoroughly. The resulting mixture exactly neutralises 26.10cm3 of 2.0 moldm-3 aqueous sodium hydroxide. What is the percentage by mass of carbon tetrachloride?

What volume of 0.11 M Na2SO4 (aq) solution at 25 °C is needed to dissolve 3.49 mg of strontium sulfate? The Ksp of strontium sulfate is 3.8×10-7 and its molar mass is 183.7 g/mol.

Aqueous 50.5 % (w/w) sodium hydroxide has a density of 1.53 g cm–3. Calculate the concentration of this solution in mol dm–3.

The molal freezing point depression constant =Kf·7.96°C·kgmol−1 for a certain substance X. When 5.40g of urea NH22CO are dissolved in 200.g of X, the solution freezes at −4.9°C. Calculate the freezing point of pure X. Round your answer to 2 significant digits.

β‑Galactosidase (β‑gal) is a hydrolase enzyme that catalyzes the hydrolysis of β‑galactosides into monosaccharides. A 0.490g sample of β‑galactosidase is dissolved in water to make 0.145 L of solution, and the osmotic pressure of the solution at 25 ∘C is found to be 0.719 mbar. Calculate the molecular mass of β‑galactosidase?

(a) One particular pungent gas is the toxic hydrogen sulphide (H2S). Hydrogen sulphide develops an odour of rotten eggs at a partial pressure of 0.13 ppm or 0.0132 Pa. If the aqueous concentration of hydrogen sulphide in the stream is 2.5 x 10–6 M, determine through calculations if the hydrogen sulphide in the water may be responsible for the odour detected near the vicinity of the stream. KH (H2S) = 0.087 M/atm)    (b)    In the leachate pond the conditions are more acidic causing NH3 to exist as NH4+. NH4+ can react with nitrites in the pond to form the less hazardous N2 and H2O as seen below: NH4+ + NO2–    →   N2 + 2H2O  You want to investigate methods of speeding up this reaction but you first conducted an initial rates test to determine the rate law equation for the reaction.  Using the data in the table below determine the rate law equation for the reaction above.     Experiment Number Initial NH4+ M Initial NO2– Initial Rate (M/s) 1 0.0100 0.200 5.4 x 10 –7…