According to the law of conservation of matter, we know that the total number of atoms does not change in a chemical reaction and thus mass is conserved. The reactant in this model is hydrogen peroxide. Hydrogen peroxide
decomposes to produce water and oxygen gas. How many water molecules must be added to complete this model?

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

multiply 2kg by latent heat of vap