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A household cleaning agent contains a weak base of general formula NaX - HSC - SSCE Chemistry - Question 23 - 2001 - Paper 1
Question 23
A household cleaning agent contains a weak base of general formula NaX. 1.00 g of this compound was dissolved in 100.0 mL of water. A 20.0 mL sample of the solution ... show full transcript
Worked Solution & Example Answer:A household cleaning agent contains a weak base of general formula NaX - HSC - SSCE Chemistry - Question 23 - 2001 - Paper 1
Step 1
What is the Brönsted–Lowry definition of a base?
Answer
The Brönsted–Lowry definition of a base is a substance that accepts protons (H⁺ ions) in a chemical reaction. In other words, when a base interacts with an acid, it allows for the transfer of protons, which is the fundamental characteristic of a base in this context.
Step 2
What is the molar mass of this base?
Answer
To calculate the molar mass of the base NaX, first determine the number of moles of hydrochloric acid (HCl) used in the titration:
The concentration of HCl is 0.1000 mol L⁻¹ and the volume used is 24.4 mL, which can be converted to liters:
Next, calculate the moles of HCl:
Since NaX reacts with HCl in a 1:1 molar ratio, the moles of NaX are also 0.00244 mol. The mass of NaX in the solution is 1.00 g. The molar mass (M) is calculated using the formula:
M = rac{ ext{mass}}{ ext{moles}} = rac{1.00 ext{ g}}{0.00244 ext{ mol}} \ \\ M = 409.84 ext{ g/mol}
Thus, the molar mass of the weak base NaX is approximately 409.84 g/mol.