Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
511–520 of 991
Question 511
4 marks · Normal
Answer and see the solution →A sample of nitric acid ( ) reacts with sodium carbonate ( ) solution. The balanced equation is:
A student titrates 25.0 cm³ of 0.150 mol/dm³ sodium carbonate. On average, 36.0 cm³ of nitric acid is required to completely react.
(a)[1 mark]According to the equation, what is the ratio of moles of nitric acid to moles of sodium carbonate required?
(b)[1 mark]Calculate the number of moles of sodium carbonate used.
(c)[1 mark]Determine the number of moles of nitric acid required to react completely.
(d)[1 mark]Calculate the concentration of nitric acid in mol/dm³.
Question 512
3 marks · Normal
Answer and see the solution →A student carries out a titration to find the concentration of a sulfuric acid solution. She adds exactly 25.0 cm³ of sodium hydroxide solution of known concentration, 0.150 mol/dm³, to a conical flask. She slowly adds sulfuric acid from a burette, using methyl orange as an indicator, until the indicator just changes colour. She records that she has used 30.0 cm³ of sulfuric acid to reach the endpoint. The balanced chemical equation for the reaction is:
Explain carefully how you would use these results to calculate the concentration of the sulfuric acid.
Question 513
2 marks · Hard
Answer and see the solution →A student is titrating calcium hydroxide solution with hydrochloric acid. The balanced chemical equation for the reaction is:
Use the balanced equation to state the mole ratio of calcium hydroxide to hydrochloric acid and explain how this ratio is used in a titration calculation.
Question 514
5 marks · Hard
Answer and see the solution →A chemistry student carries out a titration to determine the concentration of a potassium hydroxide () solution. She finds that 25.0 cm³ of solution of unknown concentration reacts exactly with 20.0 cm³ of 0.200 mol/dm³ sulfuric acid (). The balanced equation for the reaction is:
Use the three-step titration calculation method to find the concentration of the solution.
(a)[1 mark]Calculate the number of moles of reacted.
(b)[1 mark]Use the balanced equation to work out the number of moles of that reacted.
(c)[2 marks]Calculate the concentration of in mol/dm³.
(d)[1 mark]State the three-step titration calculation method used in this problem.
Question 515
2 marks · Hard
Answer and see the solution →In a titration experiment, a student uses 15.0 cm³ of 0.150 mol/dm³ hydrochloric acid to neutralise a sodium carbonate solution. Calculate the number of moles of hydrochloric acid that were used. Give your answer to three significant figures.
Question 516
1 mark · Easy
Answer and see the solution →What is the formula used to calculate the volume (in dm³) of a solution, given the number of moles and concentration in mol/dm³?
Question 517
3 marks · Easy
Answer and see the solution →Potassium hydroxide reacts with nitric acid according to the equation:
25.0 cm³ of 0.200 mol/dm³ potassium hydroxide solution is mixed with 25.0 cm³ of 0.200 mol/dm³ nitric acid.
(a)[1 mark]Calculate the number of moles of potassium hydroxide in the mixture.
(b)[1 mark]Calculate the number of moles of nitric acid in the mixture.
(c)[1 mark]State the simplest whole-number ratio of reactant volumes needed for complete neutralisation according to the equation.
Question 518
2 marks · Easy
Answer and see the solution →Calculate the volume in cm³ of 0.150 mol/dm³ sulfuric acid solution that contains 0.0300 mol of sulfuric acid.
Question 519
2 marks · Easy
Answer and see the solution →Explain why, when rearranging the concentration equation to solve for volume, the number of moles must be divided by concentration, and not the other way around.
Question 520
3 marks · Easy
Answer and see the solution →The following table shows the reaction between sodium sulfate and barium chloride:
Reactant Volume (cm³) Concentration (mol/dm³) Sodium sulfate 50.0 0.100 Barium chloride excess — Use the data given to answer the following:
(a)[1 mark]Calculate the number of moles of sodium sulfate used.
(b)[1 mark]Use the balanced equation to state how many moles of barium sulfate will be formed.
(c)[1 mark]State the minimum volume of sodium sulfate solution (in cm³) needed to ensure 0.0100 mol of barium sulfate forms, using the same concentration.