The dissolution of barium hydroxide in water is an exothermic process. which of

B

Explanation:

In an exothermic process the enthalpy of the products is smaller than the enthalpy of the reactives, in other words, the difference of enthalpy of the process (which is defined as the enthalpy at the final state of the process minus the enthalpy of the initial state) is negative. In this case, this means that the enthalpy of solid barium hydroxide plus pure water is greater than that of the solution, at the same temperature .

0.002

Explanation:

The significant figures of a number are digits that are meaningful in trying to resolve a given value. These are actually digits that carry meaning in a given number.

Let s look at  0.002, the zero before the decimal  point carries no real meaning in the number. However, the zeros that precede 2 are all meaningful because the occupy the tenth and hundreth place values.

Hence, there are three significant figure in  0.002.