Question

The relative formula mass (Mr) of a Group 2 metal carbonate is 197

Relative atomic masses (Ar): C = 12 O = 16

Calculate the relative atomic mass (Ar) of the Group 2 metal in the metal carbonate.

Name the Group 2 metal.

Answer 1

X = is the atomic relative mass of the group 2 metal.

X + 12 +16= 196

X + 28 = 196

X = 196 - 28

X = 168

the atomic relative mass of the atom of group 2 is 168

so the metal is tellerium

Answer 2

Answer : The relative atomic mass of group 2 metal in the metal carbonate is 137 and the name of the group 2 metal that has 137 relative atomic mass is barium (Ba).

Explanation :

Relative formula mass : The relative atomic masses are used to find the relative formula mass of the compound.

To determine the relative formula mass $(M_r)$ of a compound, we add the relative atomic mass values $(A_r)$ for all the atoms in its formula.

As we are given:

Relative formula mass of Group 2 metal carbonate = 197

Relative atomic masses : C = 12, O = 16

As we know that the valency of group 2 metal is 2 that means it forms $MCO_3$ metal carbonates.

As per question:

Let the relative atomic mass of group 2 metal be, 'x'. So,

$x+12+3(16)=197\\\\x+12+48=197\\\\x+60=197\\\\x=197-60\\\\x=137$

Thus, the relative atomic mass of group 2 metal in the metal carbonate is 137 and the name of the group 2 metal that has 137 relative atomic mass is barium (Ba).