JAMB - Chemistry (1990 - No. 7)

Which of the following samples will react fastest with dilute trioxonitrate (V) acid?

5 g of lumps of CacO₃ at 25°C

5 g of powered CacO₃ at 25°

5 g of lumps of CaCO₃ at 50°C

5 g of powered CaCO₃ AT 50°C