I have a PhD degree in Physics and Chemistry, I can do this job. Please review my answer for 5 questions.
Q1:
A container is kept at temperature of 400K. It contains 1L of Oxygen and 2L of Hydrogen. The pressure in the container is 735 Torr. The gas ignites and all Oxygen and Hydrogen react to create water vapor. What will be the pressure in the container after the ignition?
A1:490 Torr
Because P1V1=n1RT1, P2V2=n2RT2
Where T1=T2=400 K, n2=n1*2/3 (due to 2H2+1O2=2H2O) , V1=V2=3 L, P1=735 torr.
So P2=n2RT2/V2=n1RT1/V1*2/3=P1*2/3=490 Torr.
Q2:
One balloon contains 2 Liters of Nitrogen at a pressure of 735 Torr. Another Balloon contains 1 Liter of Oxygen at a pressure of 1470 Torr. The gas from both balloons is transfered into a third balloon at a pressure of 2940 Torr. Assuming the temperature is 298 K in all Balloons, what will be the volume of the third balloon?
A2: 1L
Because P1V1=n1RT1, P2V2=n2RT2, P1V1=n1RT1, P3V3=n3RT3
Where T1=T2=T3=298K=T, V1=2L, V2=1L, n1+n2=n3 (no reaction), P1=735 Torr, P2=1470 Torr, P3=2940 Torr, R=constant.
So V3=n3RT3/P3=(n1+n2)RT/P3=n1RT1/P3+n2RT2/P3=P1V1/P3+P2V2/P3=735Torr*2L/2940Torr+1470Torr*2L/2940Torr=1L
Q3:
Which has the largest area?
1) A triangle with three 1/3 meter edges
2) A square with four 1/4 meter edges
3) A pentagon with five 1/5 meter edges
4) A circle with 1/2 meter radius
A3: 4)
Method 1, simply calculate them and compare.
Method 2, for the equilateral polygon with certain circumference, the more the number of edges, the larger the area. When the number of edges up to infinite, the polygon can be regarded as a circle with same circumference. So the area 1)<area 2)<area 3)<…<area circle with circumference of 1 meter=area circle with 1/2pi meter radius Fe2(SO4)3 + H2
A4: 3H2SO4 + 2Fe => Fe2(SO4)3 + 3H2
Q5: Balance the following chemical equation, Burning of Butane C4H10 + O2 à CO2+H2O
A5: 2C4H10 + 13O2 à 8CO2+10H2O