a. In an experiment, 20.0 \(cm^3\) of a solution containing 4g/\(dm^3\) of sodium hydroxide was...
a. In an experiment, 20.0 \(cm^3\) of a solution containing 4g/\(dm^3\) of sodium hydroxide was neutralized by 8.0 \(cm^3\) of dilute tetraoxosulphate (VI) acid: i. Write a balanced equation for the reaction; ii. calculate the concentration of the acid in mol/ \(dm^3\)
bi. State two postulates of the Kinetic theory of gases which real gases do not obey
ii. Explain briefly why real gases do not obey the postulates stated in 2(b)(i).
c. Consider the following compound:
Name the compound
ii. name the two structural isomers of the compound;
iii. state the chemical process involved in the preparation of the compound from starch,
iv. write the chemical equation for the steps involved in the process in 2(c)(ii).
v. name two enzymes involved in the process in 2(c)(iii)
d. Explain briefly the term structural isomerism.
Explanation
ai. \(H_2SO_4 + 2NaOH → Na_2SO_4 + 2H_2O\)
ii. Concentration of NaOH(\(C_n)\)
\(C_n\) = 4/40= 0.1 mol/\(dm^3\)
\(\frac{C_AV_A}{C_nV_n} = \frac{1}{2}\)
\(C_A \times \frac{8}{0.1} \times 20 = \frac{1}{2}\)
\(C_A =0.1 \times 20 \times \frac{1}{2} \times 8 = 0.125 mol /dm^3\)
bi. -The volume of a gas is negligible compared to the total volume of the container
-There are no forces of attraction or repulsion between molecules of the gas/collision between molecules is elastic.
ii. The volume of a gas is not negligible because at high pressure the molecules occupy appreciable volume and at low temperature the
intermolecular forces of attraction and repulsion become significant.
ci. Glucose.
ii. -Fructose
-Galactose
iii. hydrolysis
iv. 2(\(C_6H_{10}O_5)_n + nH_2O → nC_{12}H_{12}O_{11}\)
\(C_{12}H_{12}O_{11} + H_2O → 2C_6H_12O_6\)
v. -maltase
-diastase
d. It Is the existence of compounds with the same molecular formula but different structural formulae/arrangement of the atoms/linkage of the atoms.