Correct Answer: A. methylpropanoate

Correct Answer: B. Sodium tetraoxosulphate (IV)

Correct Answer: D. chloride

Correct Answer: D. 3.93dm³

Correct Answer: D)

\(P_1V_1T_2 = P_2V_2T_1\)

Explanation

The ideal gas equation is an equation of state for an ideal gas, meaning it describes the relationship between pressure, volume, and temperature for a gas that follows the ideal gas law. The ideal gas law can be written as:

\(PV = nRT\) Where: - P is the pressure - V is the volume - n is the number of moles of gas - R is the ideal gas constant - T is the temperature in Kelvin When comparing two sets of conditions for an ideal gas, we can rearrange the ideal gas equation to show the relationship between the initial conditions (P?, V?, T?) and the final conditions (P?, V?, T?). This is called the combined gas law, and it can be written as: \(P_1V_1T_2 = P_2V_2T_1\) This equation shows that the product of the initial pressure, volume, and final temperature is equal to the product of the final pressure, volume, and initial temperature. This equation is the correct answer, which isOption D. The other options are incorrect because they represent specific cases of the ideal gas equation, where one or more of the variables are held constant: -Option A: \(\cfrac{V_1}{T_1} = \cfrac{V_2}{T_2}\) represents the relationship between volume and temperature when pressure is constant (Charles's law). -Option B: \(P_1V_1 = P_2V_2\) represents the relationship between pressure and volume when temperature is constant (Boyle's law). -Option C: \(V_2 = \cfrac{P_1V_1T_1}{P_2T_2}\) is a rearranged form of the combined gas law, but it does not represent the ideal gas equation in its most general form.

Correct Answer: C. palm oil

Explanation

(a) (i) let x = oxidation number of sulphur 2(1) + 2 + 3(-2) = 0

x = +2

(ii) Allotropes of sulphur are: – rhombic / alpha sulphur. – monoclinic / Beta / prismatic sulphur. – amorphous / delta sulphur. – plastic sulphur

(iii) – Macromolecule / giant molecule /3 dimensional. – carbon atoms are covalently bonded. – crystalline in nature.

(b) (i) Carbon(IV)oxide. – methane. – nitrogen(I)oxide. –water vapour – ozone – chlorofluorocarbons.

(ii) – Global warming / climate change.

(iii) – Ammonium trioxonitrate (V) /aerosol (accept ammonium nitrate). – Combustion of fuel at high temperature.

(iv)

(I) 2KNO\(_3\) --> 2KNO\(_2\) + O\(_2\)

(II) 2AgNO\(_{_3(s)}\) ---> 2Ag\(_s\) + 2NO\(_{2(g)}\) + O\(_2\)

(c) (i) – Heat the solution to concentrate it or leave in a warm place.

- partially evaporate solution and allow to cool filter off crystals.

- pick out crystals

- Dry crystals with filter paper.

(ii)(1) Ammonia readily associates with water molecules through hydrogen bonding.

(II) Chlorine molecules are smaller or chlorine molecules have fewer number of electrons and the strength of van der waals forces between molecules are weaker as compared to that of iodine OR iodine molecules are higher and the wander waal's forces between molecules are stronger as compared to that of chlorine.

(d) Mr(NaCl) = 23.0 + 35.5 = 58.5g/mol\(^1\)

Mass of NaCl = 5.85g

Molar mass of NaCl= 58.5g/mol\(^1\)

Amount of NaCl in 85g = \(\frac{5.85g}{58.5gmol^{-1}}\) = 0.1mol

1 mol of NaCI = 22.4dm\(^3\) of HCI

:. 0.1 mol = \(\frac{0.1}{1}\) x 22.4 = 2.24dm\(^3\)

OR

Molar mass NaCl = 23.0 + 35.5 = 58.5gg/mol\(^1\)

58.5g of NaCl = 22.4dm\(^3\) HCl

58.5g = \(\frac{22.4}{58.5}\) x 5.85

= 2.24dm\(^3\)

Correct Answer: A) 2.7g

Correct Answer: C) Fehling's solution

Explanation

Reducing sugars are carbohydrates that can reduce other compounds by donating electrons. Examples of reducing sugars include glucose, fructose, and maltose.

To test for the presence of reducing sugars, Fehling's solution is used. Fehling's solution is a blue-colored liquid, composed of two separate solutions: Fehling's A, which contains copper(II) sulfate, and Fehling's B, which contains potassium sodium tartrate and sodium hydroxide. When the two solutions are mixed together, a deep blue color is formed due to the copper(II) ions in the solution.

When Fehling's solution is added to a sample containing a reducing sugar and heated, the sugar reduces the copper(II) ions to copper(I) ions, which form a brick-red precipitate of copper(I) oxide. This color change confirms the presence of a reducing sugar in the sample.

The other options are not suitable for testing reducing sugars:

Correct Answer: C) 682