Question

The African bombardier beetle stenaptinus insignis can emit a jet of defensive spray from the movable tip of its abdomen. The beetle's body has reservoirs of two different chemicals. When the beetle is disturbed, these chemicals are combined in a reaction chamber producing a compounds that is warmed from ${20}^o$C to ${100}^o$C by the heat of reaction. The high pressure produced allows the compound to the sprayed out at speeds 19 ms${}^{-1}$ scaring away predators of all kinds. Assume specific heat of two chemicals and the spray to be same as that of water $[4.19\times {10}^{3}J/(kgK{)}^{-1}]$ and initial temperature of chemicals to be ${20}^o$C

Find the heat of reactions of two chemicals in J kg${}^{-1}$

• A. $8.3\times {10}^{5}J/kg$
• B. $6.7\times {10}^{5}J/kg$
• C. $4.2\times {10}^{5}J/kg$
• D. $5.3\times {10}^{5}J/kg$

Answer 1

The correct option is B $6.7\times {10}^{5}J/kg$