How many particles would be found in 2.38 g of (NH4)3PO4

Scientist wants to react a barium chloride salt with an acid. to speed up the reaction, the scientist crushes the barium chloride salt until it is a fine powder. this speeds up the reaction by a. increasing the ph of the salt. b. increasing the surface area of the salt. c. increasing the pressure of the salt. d. increasing the temperature of the salt. im thinking more a not 100% sure

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

What the blanks in these lines are ?