a 70 g sample of cesium is sealed in a glass vial and lowered into 250 mL of water at 90 C. when the cesium melted the temperature of the water dropped to 88.98 C

70.0 g  = .53 mol  

Q = 250g (+ 1.02) 4.18

Q = 1065. 9 J / 1000 = 1.0659 kJ

1.0659/ .53 = 2.01 kJ/ mol

2.01 kJ/ mol

Explanation:

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

im not exactly sure but i think its b!