F4 Chem questioin
Which of the following methoods suitable for preparing a sample of lead sulphate?
add lead to dilute sulphuric acid
add lead to CuSO4 solution
add lead(II) oxide to dilute sulpuric acid
add lead(II) nitrate solution to dilute sulphur acid
Which of the following combination（ｓ） would show a rise in temperature and give a clear solution?
Ａ：Concentrated sulphuric acid + water
Ｂ：Dilute sulphuric acid +limewater
Ｃ：dilute NaOH + dilute sulphuric acid
Thx Hiu Chung :
- 8 年前最愛解答
1. Which of the following methoods suitable for preparing a sample of lead sulphate?
add lead(II) nitrate solution to dilute sulphuric acid
since lead sulphate is insoluble in aqueous solution,
lead sulphate formed can simply be separated out by filtration.
2. Which of the following combination（ｓ） would show a rise in temperature and give a clear solution?
you are right, all three reactions are exothermic that they all show rises in temperature.
B must be wrong,
because calcium sulphate, which is insoluble in water and white in colour, is formed, so the resultant solution is milky.
I think A and C are correct because...
A:dilution of sulphuric acid
C:acid-base neutralisation, water and soluble salt (Na2SO4) are formed