Answer:
28.7 grams of water
Explanation:
Calorimetry problem:
Q = C . m . ΔT
2400 J = 4.18 J/g°C . m . (30°C - 10°C)
2400 J = 4.18 J/g°C . m . 20°C
2400J = 83.6 J/g . m
2400J / 83.6 g/J = m
28.7 g = m
10 decigrams are equivalent to 1 gram, so 2,100 grams are equivalent to 2100 x 10. This makes 21,000.
The residue of coal decomposition in the manufacture of steel is coal tar. It is a by product of the coking process in the blast furnace. Coal gas is another by product but is not the answer becuase this is not a residue which is a solid. Coal gas is a gas. Coke in fact is one of the reactants fed for steel making. Answer is choice 3.