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

呢D題目應該點做?

____________________________________

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

唔係個個都會溫度上升?什麼是CLEAR SOLUTION?

更新:

Thx Hiu Chung :

這2條我明白了

1 個解答

評分
  • 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

還有問題嗎?立即提問即可得到解答。