Question

A Silvery white metal X is in the form of ribbons. Upon ignition, it burns with a dazzling white flame to form white powder Y. When water is added to the powder Y, it partially dissolves to form a substance Z which is used as an antacid.

1. What is metal X?
2. Name the white powder Y.
3. What is the substance Z?
4. Write the chemical reaction that are taking place.

Answer 1

(a)

1. The silvery-white metal has taken in the form of ribbons which on ignition gives bright dazzling flame and forms white powder is Magnesium$\mathbf{\left(}\mathbf{Mg}\mathbf{\right)}$.
2. Hence, the metal X is Magnesium metal.

(b)

1. When the magnesium is heated, it burns with dazzling white flame and white powder of Magnesium oxide $\left(\mathbf{MgO}\right)$ is produced due to the reaction of magnesium with Oxygen $\mathbf{\left(}{\mathbf{O}}_{\mathbf{2}}\mathbf{\right)}$.
2. It is a combination type of reaction i.e., two or more substances combined to form products.
3. Hence, the white powder Y is Magnesium oxide.

(c)

1. When water is added to Magnesium oxide it partially dissolves and forms Magnesium hydroxide $\mathbf{(}\mathbf{}\mathbf{Mg}{\mathbf{\left(}\mathbf{OH}\mathbf{\right)}}_{\mathbf{2}\mathbf{}}\mathbf{)}$.
2. Hence, the substance Z that is formed is Magnesium hydroxide.

(d)

The chemical reactions that are taking place are:

$$\begin{gathered} 2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{ignition}}{\to }2\mathrm{MgO}\left(\mathrm{s}\right) \\ \left(\mathrm{X}\right)\left(\mathrm{Y}\right) \\ \mathrm{MgO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)\to \mathrm{Mg}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right) \\ \left(\mathrm{Y}\right)\left(\mathrm{Z}\right) \end{gathered}$$