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>
Take a look at the attached picture. This is not the reaction of polymerization of salicylic acid. It just shows the structure of salicylic acid and the structure when it's polymerized. The polymerization is done by connecting the salicylic acids where you produce one molecule of water.
Rutherford, Geiger and Marsden's experiment proved that every atom has a nucleus and that this nucleus is of positive charge and contains the most of the mass of the atom. 0.005% of the volume occupied by the electrons is the volume of the nucleus.
Specific heat is the amount of heat absorb or released by a substance to change the temperature to one degree Celsius. To determine the specific heat, we use the expression for the heat absorbed by the system. Heat gained or absorbed in a system can be calculated by multiplying the given mass to the specific heat capacity of the substance and the temperature difference. It is expressed as follows:
Heat = mC(T2-T1)
By substituting the given values, we can calculate for C which is the specific heat of the material.
2510 J = .158 kg ( 1000 g / 1 kg) (C) ( 61.0 - 32.0 °C)C = 0.5478 J / g °C
5-10 seconds xxx :) hope this helps
