A student adds 'x' g of iron (Fe) powder to dil. HCl and measures the work done by the reaction between HCl and the added Fe to be 1000 J. If the experiment was conducted at a constant pressure of 1 atm at $$27^\circ\text{C}$$, the mass of Fe powder added is

A

22.4 g

B

2.24 g

C

11.2 g

D

1.12 g