Group 2: Reactivity and Solubility Trends · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Down the alkaline earths

Science · Chemistry · ages 16-17
Name ______________________   Date ____________

  1. Strontium plus water gives...

    • SrO and O2
    • No products at room temperature
    • Sr(OH)2 and H2

  2. Reactions of Group 2 metals with water down the group get...

    • Less vigorous each step
    • More vigorous each step
    • No pattern down the group

  3. Hydroxides grow less soluble down Group 2.

    Circle one:   True   False

  4. How do the two solubility trends run down Group 2?

    • Hydroxides rise; sulfates fall
    • Both rise down the group
    • Hydroxides fall; sulfates rise

  5. Why does reactivity rise down Group 2?

    • The outer electrons move closer to the nucleus
    • Outer electrons move farther out behind more shells
    • The atoms gain extra neutrons in each shell

  6. Barium oxide plus water gives...

    • Ba(OH)2
    • Ba + O2 gas
    • BaSO4 salt

  7. Why does magnesium hydroxide (milk of magnesia) soothe indigestion?

    • It coats the stomach with sulfate
    • It neutralises excess acid
    • It adds acid to balance the stomach

  8. Why can barium sulfate be swallowed for a scan when barium ions are toxic?

    • Stomach acid removes every barium ion
    • The salt changes into calcium inside
    • It barely dissolves
LightMySky · lightmysky.comW1-mt_Ch8FEkh-dV-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Down the alkaline earths W1-mt_Ch8FEkh-dV-s1

  1. Sr(OH)2 and H2 · A Group 2 metal reacts with water to form its hydroxide and hydrogen: Sr + 2H2O -> Sr(OH)2 + H2.
  2. More vigorous each step · Ionisation energy falls down the group, so the outer electrons are lost more easily and the water reactions become more vigorous.
  3. False · The hydroxides become more soluble down the group. The sulfates show the falling trend.
  4. Hydroxides rise; sulfates fall · Hydroxides become more soluble, while sulfates become less soluble, down the group.
  5. Outer electrons move farther out behind more shells · Greater distance and shielding weaken the attraction between the nucleus and the outer electrons, so ionisation energy falls.
  6. Ba(OH)2 · A Group 2 oxide reacts with water to form the matching metal hydroxide: BaO + H2O -> Ba(OH)2.
  7. It neutralises excess acid · Milk of magnesia contains magnesium hydroxide. The base reacts with excess stomach acid in a neutralisation reaction.
  8. It barely dissolves · Barium sulfate is very insoluble. Very little enters solution, so most passes through the digestive system rather than supplying many barium ions to the blood.
Worksheet · LightMySky