<p>bunsen burner simply b/c u dont use a bunsen burner in titrations. analytical balance, however, u do because u need to measure the mass of the acid/base ur titrating</p>
<p>Member-
Yes 1L O2 remaining.</p>
<p>Can anyone explain the T/F one with average kinetic energy? Something about if some of the liquid in an insulated container is evaporated, what would happen to the temperature of the container and the average KE of the molecules?</p>
<p>I put that the temperature wouldn’t change since it’s insulated and that the AVERAGE KE of the molecules under those that evaporated would not change. Any ideas?</p>
<p>@ilikebananas…
I think the question was Evaporation of water is an endothermic reaction which is correct because it absorbs heat for it to break bonds and set the substance apart. Which is True
The second part i believe was evaporation causes an increase on entropy which is also correct.
True
It is not CE though cause the entropy does not explain the endo reaction</p>
<p>Why is it only 1 L O2
I thought it was 2</p>
<p>I agree with the previous post (wangh1)</p>
<p>Isn’t hydrogen + oxygen -> H2O exothermic?</p>
<p>H2 reacts twice as much as O2 does. There are 3 moles of O2 and 4 moles of H2. All of the H2 would react with 2 moles of O2 to produce H20. Thus, 4-3 = 1 mole left.</p>
<p>H+ + CaCO3 produces:</p>
<p>1 mol Ca2+
2 mol CO2
1 mol H2O</p>
<p>CaCO3 + excess H+ –> Ca++ + CO2 + H2O
products are all 1 mol.</p>
<p>peter-</p>
<p>Haha, i don’t remember exactly what I put. I remember that question, number 45, but I put I, II, and III. I remembered that</p>
<p>It was I and III. There is only 1 mol of CO2. What did you guys put for the law of conservation of energy one?</p>
<p>Crap… I left 2 blank and 6 wrong… what is an estimate of my score</p>
<p>1 = 2 + 3.</p>
<p>what is usually the cut off of the 800s
also i am pretty sure it wasnt the bunsen burner since if you used the bunsen burner you could evap all the water leaving you with the salt, but i am not sure
also for the true false kinetic energy one can someone explain that</p>
<p>I put that the temperature wouldn’t change since it’s insulated and that the AVERAGE KE of the molecules under those that evaporated would not change. Any ideas?</p>
<p>you have to balance out the equation:
2H2 +O2 yields 2 moles of water…
4 moles of Water(in problem)/2=2 L
3/1=3 L of Oxygen…Since oxygen is the livng reagent… Oxygen contains 1 more L of it.</p>
<p>^^the TF one with H2 and O2 gas?</p>
<p>umm
did you guys get 1.47 or 14.7?
did you guys get 9.24??</p>
<p>Usually, the cut off for 800 is a raw score of 82, which means up to 2 wrong or 0 wrong/3 blank.</p>
<p>I got 1.47, and explain the problem with 9.24</p>
<p>hydrogen has a faster average speed b/c its root (3RT/Molar mass). So ur dividing by a smaller number therefore greater. However, Oxygen has a faster average kinetic energy b/c its 1/2mv^2, and oxygen’s mass is greater than hydrogen. F,T</p>
<p>I thought average kinetic energy is the same because temperature is average kinetic energy (they were both at 25C). so F, F ?</p>