Assuming we have a 100g sample, the mass of each element is as follows:
C: 74 g
H: 7.4 g
N: 8.6 g
O: 10 g
Next, we calculate the moles of each by dividing the mass of each element by its molar mass:
C: (74 / 12) = 6.17
H: (7.4 / 1) = 7.4
N: (8.6 / 14) = 0.61
O: (10 / 16) = 0.625
Now, we take the smallest value to determine the ratio:
C: 10
H: 12
N: 1
O: 1
Thus, the empirical formula can be expressed as
C10H12NO
Hello! The mass percent composition of nitrogen in NH₄OH is 14/35×100. To find the percent composition by mass of an element within a chemical compound, divide the atomic mass of that element (AM), which is 14 for Nitrogen, by the entire compound's molar mass (MM) and multiply that by 100. The formula for determining percent composition is as follows: Have a nice day!
Answer:
Explanation:
Assuming all calculations occur at standard pressure and a temperature of -1.72°C :
Where
is the number of moles of hydrogen
is the mass of hydrogen
is the density of hydrogen
According to the Law, the variation in internal energy (U) of the system is equal to the total of the heat added to the system (q) plus the work performed ON the system (W)
<span>ΔU = q + W </span>
<span>In response to the first question, 0.653 kJ of heat energy is extracted from the system (balloon) while 386 J of work is applied to the balloon, leading to </span>
<span>ΔU = -653J + 386J </span>
<span>=-267J </span>
<span>Thus, the internal energy reduces by 267 J </span>
<span>For the second question, 322 J of heat is supplied to the system (gold bar) while no work is undertaken on the gold bar, marking this as an isochoric/isovolumetric process, thus </span>
<span>ΔU = 322J + 0 </span>
<span>=322J </span>
<span>Hence, internal energy rises by 322 J</span>
1) To express 0.89% m/v, it equals 0.89 grams of NaCl per 100 ml of solution.
This corresponds to 8.9 grams of NaCl in 1000 ml of solution, or 8.9 grams in 1 liter.
2) Molarity is represented as M = moles of solute / liters of solution.
Thus, we need to determine the moles in 8.9 grams of NaCl.
3) The molar mass of NaCl is calculated as 23.0 g/mol + 35.5 g/mol = 58.5 g/mol.
4) Therefore, the number of moles of NaCl calculates as mass / molar mass = 8.9 g / 58.5 g/mol = 0.152 moles.
5) Consequently, M = 0.152 moles of NaCl / 1 liter of solution = 0.152 M.
Answer: 0.152 M
