Nitrogen with a mass of 25 kg expands at a constant pressure...

Nitrogen with a mass of 2.5 kg expands at a constant pressure. The initial pressure and temperature in the piston cylinder system is 170 kPa and 27 oC, respectively. Because of the heat transfer, the system reached a final temperature of 200 oC. Note R= 0.2968 kJ/kgK Determine: a. The heat required b. The work c. The change of enthalpy d. The change of internal energy

Transcript

00:01 Equation we are given here nitrogen with a mass so we are given here nitrogen and its mass we are given here and which is equal to 2 .5 kilogram and is expanding with the constant pressure so pressure we are given here is constant so we are given here constant pressure pressure and temperature temperature in a piston cylinder we are given here the initial pressure we can write initial pressure it is 170 kilo pascal and its temperature we are given here the temperature is t which is equal to 27 centigrade and now because of the heat transfer the system bridge is the final temperature so we can write this initial temperature and its final temperature rate is so final temperature is 200 centigrade now the r value we are given here so we can write value of r which is equal to the value is through 0 .2968 kilojoule per kilogram multiplied by kelvin and let's determine the first support of this equation so in the first of part a here we want to find here in this a we want to find heat require so how much the heat require we want to find is so heat h which is equal to where denoted by here the capital so capital h which is equal formula is n multiplied by cp multiple by delta d.

01:26 So how to find this? so we can convert h which is equal to value of n that is here we have 2 .5 2 .5 kilogram and value of cp is say 1 divided by 2 multiplied by r and temperature we are given here that r r we know that and temperature is 200 minus 27 and we know the value of r is to 0 .2968 now here let's we just simplify and we can where your answer is 449 .449 .3 kilojoule that is that number of 8 is required.

02:01 Now let's allow our second support of this question.

02:05 So in the second support of this question we want to find is wok.

02:09 Here we want to find is walk.

02:12 So how to find this? so walk which is equal to we know that the formula here is the n multiple by r multiple we can buy t2 minus t1 now we just simplify and we can write here answer is so here we just simplify our values so we can value of n is 2 .5 multiply we can write to 0 .2968 1ly 6 8 where we can write here 200 minus 27 now we just simply find we can write here answer is 128 .366 kilojou so this is the value of now let's follow our thoughts of this question so in the thoughts of part of this question see we want to find this here and thalp change in enthalpy here we want to find change in enthalpy which is equal we can write heat heat at constant pressure so heat at pressure p is constant heat at pressure p is constant so we want to find this so we know that heat pressure p is constant which is equal answer is 449 3 kilojoule so this is the value of and and now let's solve our fourth part of this question.

03:28 So in the fourth part we want to find is change in internal energy.

03:31 So here we want to find a change in an internal energy...

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