Find the moles of CaO
divide mass (2.0g) by the RFM which is 56 (Ca is 40 add that to O which is 16 making 56) this gives 0.0356 moles.
Find the theoretical mass by multiplying the moles of CaO (which is 0.0356 as there are no balancing number making the ratio 1:1) by the RFM of Ca(OH)2 which is 74 (40+16+16+1+1)
74 (Ca(OH)2 RFM) x 0.0357 (CaO moles) = 2.6g which is the theoretical mass of Ca(OH)2
Find percentage yield by dividing the actual mass of Ca(OH)2 by the theoretical and then x100 this Should give you 82.3%
An elements like helium and Boron are formed by stars having a mass of one to eight suns. The example elements that are formed by stars having a mass of one to eight suns are helium and boron. The stars normally turns into a white dwarf when the mass of the stars are less than 5 times the mass of the sun.
Answer:
This question is incomplete
Explanation:
This question is incomplete because the result of the described experiment would have better determined the type of scientific explanation to profer. However, the type of material that will preserve the relative hotness or temperature of the hot coffee for the longest time will be a material than can resist heat transfer. These materials tend to keep hot substances hot by not allowing the heat of the coffee to be conducted or pass through it. These materials are mostly insulators or made by placing an insulator between two heat conductors.
Generally, heat is usually transferred from a region of higher concentration to a region of lower concentration, hence when the heat is denied of this transfer, the heat will remain trapped in the "heat-donor" substance (in this case the hot coffee). Thus, the material chosen (A, B or C) will be the material that resists heat transfer the most based on the explanation above.
According to the reaction equation:
and by using ICE table:
CN- + H2O ↔ HCN + OH-
initial 0.08 0 0
change -X +X +X
Equ (0.08-X) X X
so from the equilibrium equation, we can get Ka expression
when Ka = [HCN] [OH-]/[CN-]
when Ka = Kw/Kb
= (1 x 10^-14) / (4.9 x 10^-10)
= 2 x 10^-5
So, by substitution:
2 x 10^-5 = X^2 / (0.08 - X)
X= 0.0013
∴ [OH] = X = 0.0013
∴ POH = -㏒[OH]
= -㏒0.0013
= 2.886
∴ PH = 14 - POH
= 14 - 2.886 = 11.11
Answer:
Fluid power systems perform work by a pressurized fluid bearing directly on a piston in a cylinder or in a fluid motor. A fluid cylinder produces a force resulting in linear motion, whereas a fluid motor produces torque resulting in rotary motion. Within a fluid power system, cylinders and motors (also called actuators) do the desired work. Control components such as valves regulate the system.
