A mixture of 2.0 mol of H2( g) and 1.0 mol of O2( g) is placed in a sealed evacuated container made of a perfect insulating material at 25 °C. The mixture is ignited with a spark and reacts to form liquid water. Determine the temperature of the water.

Video transcript

Hey everyone welcome back for this question, We were told that hydrogen gas reacts with chlorine gas to produce hydrogen chloride gas. And before we move forward, let's go ahead and bounce out our reaction and we can do this by simply adding a coefficient of two prior to our hydrogen chloride. Now we can go ahead and think about the equation. We can use to answer our question of determining the temperature of hydrogen chloride. So the equation that comes to mind is going to be our Q equals M C delta T. And we can go ahead and find some of the values for this equation by looking at the back of our textbooks. So for example, we know that negative Q of our reaction is the same as a standard entropy of formation of hydrogen chloride. And this is going to be negative 92.3 kg joules per mole. So essentially our Q. is going to be 92.3 kg jewels Permal. And we can also find our seat which is our specific heat. And we know that our specific heat is going to be 29.14 jules over mall times degrees Celsius. Now let's go ahead and plug in our values. So for Q We can add our 92. Killer jewels over one mole and we can go ahead and convert our killer jewels into jewels. And we know one killer jewel is equivalent to 10 to the third jewels and we can equal this to R M C delta T. So M is going to be Our 2.3 mole of each gas. So for example, we're going to write hydrogen gas and we need to convert this to hydrogen chloride. So we know that we have a 1-2 ratio. So one mole of hydrogen gas is equivalent to two mole of hydrogen chloride. And for our specific heat, we found that 29.14 jules over mole times degrees Celsius was our specific heat for hydrogen chloride. And lastly, we were told that our container was initially at 23.2°C. So Delta T. Is going to be our final temperature And we subtract that by 23 .2°C. Now when we calculate this out and cancel out our units, our final temperature is going to come up 711 .5°C. So I hope this made sense. And let us know if you have any questions.