What is the molar mass of 0.250 mol of aluminium sulfate (Al₂(SO₄)₃)? [Al = 27.0, S = 32.1, O = 16.0]

Here are the solutions to the questions from the image: 1. (a) What is the molar mass of 0.250 mol of aluminium sulfate (Al_2(SO_4)_3)? Given atomic masses: Al = 27.0, S = 32.1, O = 16.0. Step 1: Calculate the molar mass of Al_2(SO_4)_3. The formula Al_2(SO_4)_3 means there are 2 Aluminium atoms, 3 Sulfur atoms (from 3 × S), and 12 Oxygen atoms (from 3 × 4 × O). Molar mass = (2 × Al) + (3 × S) + (12 × O) Molar mass = (2 × 27.0) + (3 × 32.1) + (12 × 16.0) Molar mass = 54.0 + 96.3 + 192.0 Molar mass = 342.3 g/mol The molar mass of aluminium sulfate is a constant value, regardless of the number of moles. Step 2: State the molar mass. The molar mass of aluminium sulfate is 342.3 g/mol. The quantity of 0.250 mol is extra information if the question strictly asks for "molar mass". If it asked for the "mass of 0.250 mol", the calculation would be different. The molar mass of aluminium sulfate (Al_2(SO_4)_3) is 342.3 g/mol. 1. (b) Write the formula for each of the following ions: (i) carbonate (IV) ion (ii) nitrate (V) ion (i) Carbonate (IV) ion: CO_3^2- (ii) Nitrate (V) ion: NO_3^- 1. (c) Name the following organic compounds: (i) CH_3CH_2CH(Br)CH_3 (ii) CH_3COCH_2CH_3 (i) CH_3CH_2CH(Br)CH_3: This is a butane chain with a bromine substituent. Numbering the carbon chain from the right gives the bromine the lowest possible number (carbon 2). 2-bromobutane (ii) CH_3COCH_2CH_3: This is a ketone with a 4-carbon chain. The carbonyl group (C=O) is on the second carbon from either end. Butan-2-one 3 done, 2 left today. You're making progress.