Answer:
<u>8.08 × </u>
<u> atoms of hydrogen</u>
Explanation:
From the given data, we have two categories of variables (unknowns):
- Amount (moles or mass) of Caffeine
- Amount (moles or mass) of Hydrogen
The longer route would be to solve for these variables first, by determining the number of moles of the Caffeine sample (0.134 moles of C8H10N4O2) from the mass of carbon (12.89 g = 1.07 moles in 6.47 atoms) provided. And then solve for the number of atoms of H. <u><em>[N.B: 1 mole of ANY substance = 6.022 × </em></u><u><em> atoms ]</em></u>
Alternatively and quicker, we can use the mole ratios of the Carbon:Hydrogen atoms in the compound.
8 : 10 ≡ 4 : 5
If 4 moles -- 6.47 atoms
Then 5 moles -- ?? atoms
⇒ No. of atoms of Hydrogen = 
<u>=8.08 × </u><u> atoms of hydrogen</u>
Answer:
At the burner temp. and pressure, 18.85 litres of air is needed to completely combust each gram of propane
Explanation:
The combustion stoichiometry is as follows:
C₃H₈ + 5O₂ = 4 H₂O + 3CO₂ The molecular weights (g/mol) are:
MW 44 5x32 4x18 3x44
So each gram of propane is 1/44 = 0.02272 mol propane
and will need 5 x 0.02272 = 0.1136 mol oxygen
At 0.21 mol fraction oxygen in air, 0.1136 / 0.21 = 0.54 mol air is needed to burn the propane.
At the low pressure in the burner we can use the Ideal Gas Law
PV=nRT, or V = nRT/P
P = 1.1 x 101325 Pa = 111457 Pa
T = 195°C + 273 = 468 K
R = 8.314
and we calculated n = number of moles air = 0.54 mol
So V m³ = 0.54 x 8.314 x 468 / 111457 = 0.0188 m³ = 18.85 litres air.
The answer is ................................ c
The organic compound retinal binds with opsin and forms rhodopsin. Retinal is part of the molecule that is responsible for its color. This part is called chromophore. On the other hand, opsins are the proteins in photoreceptor cells. Retinal bounds with these opsins and forms rhodopsin: the basis of the human vision. Rhodopsin is also a protein.It is the pigment in the retinas of humans and animals.
Number 1 Bc of wood a magnetic
