Asample of gas with a volume of 750 ml exerts a pressure of 98 kpa at 30◦c. what pressure will the sample exert when it is compressed to 250 ml and cooled to −25◦c?

241 kPa

Explanation:

The ideal gas law states that:

where

p is the gas pressure

V is its volume

n is the number of moles

R is the gas constant

T is the absolute temperature of the gas

We can rewrite the equation as

For a fixed amount of gas, n is constant, so we can write

Therefore, for a gas which undergoes a transformation we have

where the labels 1 and 2 refer to the initial and final conditions of the gas.

For the sample of gas in this problem we have

So we can solve the formula for , the final pressure:

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.