Answer:
C8H17N
Explanation:
Mass of the unknown compound = 5.024 mg
Mass of CO2 = 13.90 mg
Mass of H2O = 6.048 mg
Next, we shall determine the mass of carbon, hydrogen and nitrogen present in the compound. This is illustrated below:
For carbon, C:
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Mass of C = 12/44 x 13.90 = 3.791 mg
For hydrogen, H:
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mass of H = 2/18 x 6.048 = 0.672 mg
For nitrogen, N:
Mass N = mass of unknown – (mass of C + mass of H)
Mass of N = 5.024 – (3.791 + 0.672)
Mass of N = 0.561 mg
Now, we can obtain the empirical formula for the compound as follow:
C = 3.791 mg
H = 0.672 mg
N = 0.561 mg
Divide each by their molar mass
C = 3.791 / 12 = 0.316
H = 0.672 / 1 = 0.672
N = 0.561 / 14 = 0.040
Divide by the smallest
C = 0.316 / 0.04 = 8
H = 0.672 / 0.04 = 17
N = 0.040 / 0.04 = 1
Therefore, the empirical formula for the compound is C8H17N
Answer:
17.5 g
Explanation:
Given data
- Mass of solution to be prepared: 50.0 grams
- Concentration of the salt solution: 35.0%
The concentration by mass of NaCl in the solution is 35.0%, that is, there are 35.0 grams of sodium chloride per 100 grams of solution. We will use this ratio to find the mass of sodium chloride required to prepare 50.0 grams of a 35.0% salt solution.
Soil.
Heterogeneous means is can be separated and soil can be taken apart and separated according to its contents. (Rocks, dirt, grass). <span />
The boiling point decreases as the volume decreases.
<u>Explanation:</u>
The Temperature - Volume law otherwise called as Charles law is applied, which says that the volume of the given gas at constant pressure is directly proportional to the temperature measured in Kelvin. As the volume increases, the temperature also increases, if the volume decreases, then the temperature also decreases.
As per the Charles law, here the volume is decreased from 50 ml to 25 ml so the boiling point also decreases.
Heat given out to the surroundings by the system = 225 J
Work done by the system on the surroundings = 645 J
According to the energy conservation, the energy can neither be created nor it can be destroyed, it can transform from one form to another. Hence, the energy which is lost to the surrounding as a work done and heat came from the internal energy of the system.
Hence, the change in the internal energy = - 225 - 645 = - 870 Joules
Negative sign means that the internal energy of the system is decreased by 870 Joules
