A sample of cobalt (specific heat of Co = 0..418 J/g˚C) at 200.0˚C is dropped into a calorimeter containing 50.0 mL of water at 21.1˚C. The final temperature of the water/cobalt mixture was 67.1˚C. What was the mass of the sample of cobalt?

The answer is d. hope i !

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b

B.carbon sequestration

Hello, i think is ahope it