Question

The equivalent volume of hydrogen at STP from one gram of a divalent metal when treated with a
dilute mineral acid is 560 ml, calculate the atomic mass of metal
with an explanation​

Answer 1

Answer:

40 grams

Explanation:

Let us first see the chemical reaction between dilute acid and the divalent metal

M+ 2H+=H2 + M2+

From the above equation we can see that 1 mole of divalent metal liberates 1 mole of H2.

Now first let us calculate moles of H2 in 560ml or 0.560L of H2 gas.

Given density of H2 gas is 0.08988 g/L

Mass = Density x volume

Mass = 0.0503 gram

Number of moles  = mass / molar mass

Number of moles = 0.0503 / 2  = 0.025

Now 0.025 moles of H2 means we had 0.025 moles of metal

0.025 = 1 / molar mass

Molar mass = 1/0.025 = 40 g