A gas is contained in a horizontal cylinder with a moveable piston of cross-sectional area 0.33\text{ m}^20.33 m 2 . The region outside the cylinder is at standard ambient temperature and pressure, 298\text{ K}298 K and 1\text{ bar}1 bar. When 2040\text{ J}2040 J of heat flow into the gas, the internal energy of the gas increases by 1380\text{ J}1380 J. Calculate the distance through which the piston moves. You may assume friction is negligible.

0.02 m

Explanation:

∆U = q + w

w = ∆U - q = (1380 - 2040) J = -660 J

w = -p∆V = -pA∆h

∆h = -w/(pA)

p = 1 bar × (100000 Pa/1 bar) = 100000 Pa

∆h = -(-660 J)/(100000 Pa×0.33 m²) = 0.02 m

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.