What are solid figures?© BrainMass Inc. brainmass.com October 16, 2018, 3:46 pm ad1c9bdddf
Before you learn about solid figures, learn about the circle, square, triangle and other such polygons (polygons = closed plane structures with many sides)
Unlike plane figures, solid figures are not flat, they have a three dimensional look.
Sphere, cone, cylinder are examples ...
The expert explains the solid figures with examples.
Buffer Solution and Entropy
1-A 1.0-L buffer solution is 0.105M in HNO 2 and 0.145M in NaNO 2. Determine the concentrations of HNO 2 and NaNO 2 after addition of 1.4g NaOH .Express your answers using three significant figures separated by a comma.
2- A 1.0-L buffer solution is 0.105M in HNO 2 and 0.145M in NaNO 2. Determine the concentrations of HNO 2 and NaNO 2 after addition of 1.4g HI. Express your answers using three significant figures separated by a comma.
3- Which processes are nonspontaneous?
a bike going up a hill
a meteor falling to Earth
obtaining hydrogen gas from liquid water
a ball rolling down a hill
4-predict the sign of ΔS sys for each chemical reaction. ΔS sys >0 or ΔS sys <0
2KMnO 4 (s)→K 2 MnO 4 (s)+MnO 2 (s)+O 2 (g)
CH 2 =CH 2 (g)+H 2 (g)→CH 3 CH 3 (g)
Na(s)+1/2Cl 2 (g)→NaCl(s)
N 2 (g)+3H 2 (g)→2NH 3 (g)
5-Why does a gas have greater entropy than the corresponding solid? Choose from:
The entropy change of sublimation (solid going directly to gas) is positive.
There are more available types of kinetic energy in a gas. In a solid, the molecules can only vibrate.
A gas expands to fill its container, while a solid maintains a constant shape.
Particles in a solid move slower than in a gas.