Chemistry Q1a – Investigate the use of solubility equilibria | HSC HSC Practice – StudyPulse
StudyPulse Logo
Sign Up
StudyPulse Sign up free

Chemistry HSC HSC Practice Question 1a – Investigate the use of solubility equilibria

Q1a Chemistry Investigate the use of solubility equilibria Module 5 - Outcome 4

Aboriginal and Torres Strait Islander Peoples have long used repeated soaking and rinsing steps to remove water-soluble toxins from cycad fruit before consumption. In a simplified model, a toxic component in cycad fruit is represented by an ionic compound \(TX(s)\) that dissolves and establishes the solubility equilibrium:

\[TX(s) \rightleftharpoons T^+(aq) + X^-(aq)\]

At \(25^\circ\text{C}\), the solubility product is \(K_{sp}(TX)=4.0\times 10^{-6}\).

A sample of prepared cycad fruit is modelled as containing excess solid \(TX\) in contact with \(1.00\ \text{L}\) of water. After soaking, the water is discarded and replaced with fresh water of the same volume. Assume that:

  • the temperature remains constant at \(25^\circ\text{C}\)
  • each soak lasts long enough for the solution to reach equilibrium with excess solid \(TX\)
  • no solid is lost when the water is discarded (solid remains with the fruit)
  • volumes are exactly \(1.00\ \text{L}\) each time.

In a variation of the process, the second soak uses \(1.00\ \text{L}\) of \(0.10\ \text{mol L}^{-1}\) sodium chloride solution instead of pure water. Treat \(\text{NaCl}\) as fully dissociated and ignore any complex ion formation.

Question 1a

2 marks

Calculate the equilibrium concentration of \(T^+(aq)\) in the soaking water after the first soak in pure water.

Your Answer

0 words

About This Chemistry Question

This is a free HSC HSC Chemistry practice question worth 2 marks, testing your understanding of Investigate the use of solubility equilibria. It falls under Solution Equilibria in Module 5: Module 5: Equilibrium and Acid Reactions. Submit your answer above to receive instant AI-powered marking and personalised feedback.

Subject
Chemistry – Higher School Certificate (NSW) HSC
Module 5
Module 5: Equilibrium and Acid Reactions
Outcome 4
Solution Equilibria
Content Point
Investigate the use of solubility equilibria

Module 5 Overview

Chemical systems may be open or closed. They include physical changes and chemical reactions that can result in observable changes to a system. Students study the effects of changes in temperature, concentration of chemicals and pressure on equilibrium systems, and consider that these can be predicted by applying Le Chatelier’s principle. Students also analyse the quantitative relationship between products and reactants in equilibrium reactions to determine an equilibrium constant. From this calculation, they predict the equilibrium position, either favouring the formation of products or reactants in a chemical reaction. This module also allows students to understand that scientific knowledge enables scientists to offer valid explanations and make reliable predictions. Students make reliable predictions by comparing equilibrium calculations and equilibrium constants to determine whether a combination of two solutions will result in the formation of a precipitate.

Solution Equilibria

Inquiry question: How does solubility relate to chemical equilibrium?

Content Point Detail

investigate the use of solubility equilibria by Aboriginal and Torres Strait Islander Peoples when removing toxicity from foods, for example: - toxins in cycad fruit

Want more Chemistry practice questions?

StudyPulse has thousands of HSC Chemistry questions with full AI feedback, mark breakdowns, progress tracking, and study notes across every Content Point point including Investigate the use of solubility equilibria.

Create Free Account Browse More Chemistry Topics