How do you work out instantaneous speed?

What is the type of the reaction below? bacl2 + h2so4 → 2 hci + baso4 double replacement synthesis single replacement decomposition

Select for each of the following statements whether it is correct or incorrect. (a) in an isothermal expansion of an ideal gas. (b) the temperature remains constant. (b) the pressure remains constant. (c) there is work done by the gas. (d) there is heat added to the gas. (e) the change in internal energy equals zero.

Acid precipitation chemically weathering a 5.0-kg limestone rock . which coukd be the result ?