Weight percentage of nitrogen can be calculated using the following rule:
weight percentage of nitrogen = (weight of nitrogen / weight of urea) x 100
From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of nitrogen = 14 grams
molecular mass of hydrogen = 1 grams
molecular mass of oxygen = 16 grams
therefore:
mass of nitrogen in urea = 2(14) = 28 grams
mass of urea = 12 + 2(14) + 4(1) + 16 = 60 grams
Substitute with the masses in the equation to get the percentage:
weight percentage of nitrogen = (28/60) x 100 = 46.667%
Answer:
(a) SeF₄
(b) OF₂
(c) N₂O
(d) PCl₃
Explanation:
Write the formula for each compound.
(a) selenium tetrafluoride. According to the name, this compound has 1 atom of Se and 4 atoms of F. The resulting formula is SeF₄, in which Se has the oxidation number 4+ and F has the oxidation number 1-.
(b) oxygen difluoride. According to the name, this compound has 1 atom of O and 2 atoms of F. The resulting formula is OF₂, in which the oxidation number of O is 2+ and the oxidation number of F is 1-.
(c) dinitrogen monoxide. According to the name, this compound has 2 atoms of N and 1 atom of O. The resulting formula is N₂O, in which the oxidation number of N is 1+ and the oxidation number of O is 2-.
(d) phosphorus trichloride. According to the name, this compound has 1 atom of P and 3 atoms of Cl. The resulting formula is PCl₃, in which the oxidation number of P is 3+ and the oxidation number of Cl is 1-.
Answer:
6.5 liters.
Explanation:
- We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
- If P and T are constant, and have different values of n and V:
<em>(V₁n₂) = (V₂n₁)</em>
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V₁ = 4.5 L, n₁ = 0.80 mol,
V₂ = ??? L, n₂ = 0.35 + 0.80 = 1.15 mol.
- Applying in the above equation
<em>(V₁n₂) = (V₂n₁)</em>
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<em>∴ V₂ = (V₁n₂)/n₁ </em>= (4.5 L)(1.15 mol)/(0.8 mol) = <em>6.469 L ≅ 6.5 L.</em>
<em></em>
<em>So, the right choice is: 6.5 liters.</em>
Answer:
Atmospheric Pressure:
- It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. In a barometer, a column of mercury in a glass tube rises or falls as the weight of the atmosphere changes.
Explanation:
Hope this helps
