A solid E was put in a boiling tube and 10cm³ of distilled water was added. The mixture was shaken thoroughly and the solid dissolved. The resulting solution was divided into five portions. a) Place a

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16. Use the information to answer questions that follow: Solid E was put in a boiling tube and $10\text{cm}^3$ of distilled water was added. The mixture was shaken thoroughly and the solid dissolved. The resulting solution was divided into five portions. a) Place about a half spatula full of the solid into a clean dry test tube. Heat gently.

    Observation	Inference
    The solid melts, and a colorless liquid condenses on the cooler parts of the test tube. The solid may change color (e.g., blue to white) or remain white.	Hydrated compound

    b) Place all the remaining portion of the solid in the test tube. Add about $10\text{cm}^3$ of distilled water, shake thoroughly. Divide the mixture into five portions.

    Observation	Inference
    The solid dissolves to form a colorless solution.	Soluble compound

    c) To the first portion, add three drops of sodium hydroxide then add excess.

    Observation	Inference
    A white precipitate is formed, which dissolves in excess sodium hydroxide.	$\text{Zn}^{2+}$, $\text{Pb}^{2+}$, $\text{Al}^{3+}$ present

    d) To the second portion, add three drops of aqueous ammonia then add excess.

    Observation	Inference
    A white precipitate is formed, which is insoluble in excess aqueous ammonia.	$\text{Al}^{3+}$, $\text{Pb}^{2+}$ present

    e) To the third portion, add three drops of sodium sulphate solution.

    Observation	Inference
    No precipitate is formed.	$\text{Al}^{3+}$ present

    f) To the fourth portion, add three drops of lead (II) nitrate solution and preserve the product to be used in (g) below.

    Observation	Inference
    White precipitate	$\text{SO}_4^{2-}$, $\text{Cl}^{-}$ present

    g) To the portion in (iv) above, add five drops of dilute hydrochloric acid.

    Observation	Inference
    The white precipitate remains insoluble.	$\text{SO}_4^{2-}$, $\text{Cl}^{-}$ present

    h) To the fifth portion, add three drops of barium nitrate solution.

    Observation	Inference
    White precipitate	$\text{SO}_4^{2-}$ present

    i) Identify the cation and anion present:
    Cation: $\boxed{\text{Al}^{3+}}$
    Anion: $\boxed{\text{SO}_4^{2-}}$

    j) Identify Compound E:
    Compound E: $\boxed{\text{Aluminium Sulphate}}$