When a metal X is treated with cold water, it gives a base Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z, which easily catches fire. Identify X, Y and Z and also write the reaction involved.

Open in App

Solution

Molecular mass of $X + O + H = 40$
$\to X + 16 + 1 = 40$
$\to X = 23$
Only Na has the molecular mass of 23. Therefore, X is sodium
[0.5 Marks] and Y is sodium hydroxide as it has molecular mass 40.
[0.5 Marks]

Sodium on reaction with cold water gives out sodium hydroxide, hydrogen gas and heat energy. The reaction occurs as follows:

$2 Na(s) + 2 H_{2} O(cold) \to 2 NaOH(aq) + H_{2} (g) + Heat energy$
[0.5 Marks]

Hydrogen gas easily catches fire. Therefore, Z is hydrogen gas.
[0.5 Marks]

Suggest Corrections

Similar questions

Question 42
When a metal X is treated with cold water, it gives a base Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z, which easily catches fire. Identify X, Y and Z and also write the reaction involved.

Q. When a metal

X

is treated with cold water, it gives a basic salt

Y

with molecular formula

X O H

(molecular mass

= 40

) and liberates a gas

Z

which easily catches fire. Identify

X, Y

and

Z

Q. When a metal X is treatwd with cold water it gives a basic salt Y with molecular formula XOH (molecular mass=40) and liberates a gas Z. Identify X, Y and Z and also write the reactions involved

Q. An monovalent metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.

Q. An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.

Join BYJU'S Learning Program