Equivalent weight of a metal carbonate is determined by the amount of the metal that can react with one equivalent of an acid. To calculate the equivalent weight, we need to determine the moles of the metal carbonate and the moles of the acid used in the reaction.

First, let's calculate the moles of N/2 H2SO4 used in the reaction:

Given:
Volume of N/2 H2SO4 = 40 ml
Normality (N) = 2

Normality is defined as the number of equivalents of solute present in one liter of a solution. For H2SO4, the number of equivalents is equal to the number of acidic hydrogen ions it can donate, which is 2 in this case.

Moles of H2SO4 = (Normality × Volume) / 1000
= (2 × 40) / 1000
= 0.08 moles

Now, let's calculate the moles of the metal carbonate:

Given:
Mass of metal carbonate = 0.84 g

To find the moles, we need to know the molar mass of the metal carbonate. Let's assume the formula of the metal carbonate is MCO3, where M represents the metal.

The molar mass of MCO3 = atomic mass of M + (3 × atomic mass of oxygen)
Let's assume the atomic mass of M = x g/mol.

Molar mass of MCO3 = x + (3 × 16)
= x + 48 g/mol

To calculate the moles, we use the formula:

Moles of metal carbonate = Mass of metal carbonate / Molar mass of MCO3
= 0.84 g / (x + 48) g/mol
= 0.84 / (x + 48) moles

Since the moles of the metal carbonate and the moles of the acid are equal in a balanced chemical equation, we can equate the two:

0.08 moles of H2SO4 = 0.84 / (x + 48) moles of metal carbonate

Now, let's solve for x:

0.08(x + 48) = 0.84
0.08x + 3.84 = 0.84
0.08x = 0.84 - 3.84
0.08x = -3
x = -3 / 0.08
x = -37.5

Since the atomic mass cannot be negative, there must be an error in the calculations or the given data. Please double-check the values provided and ensure they are accurate.

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