Answer is: the partial pressure of the helium gas is 0.158 atm.
p(mixture) = 0.48 atm; total pressure.
m(H₂) = 1.0 g; mass of hydrogen gas.
n(H₂) = m(H₂) ÷ M(H₂).
n(H₂) = 1.0 g ÷ 2 g/mol.
n(H₂) = 0.5 mol; amount of hydrogen.
m(He) = 1.0 g; mass of helium.
n(He) = 1 g ÷ 4 g/mol.
n(He) = 0.25 mol; amount of helium.
χ(H₂) = 0.5 mol ÷ 0.75 mol.
χ(H₂) = 0.67; mole fraction of hydrogen.
χ(He) = 0.25 mol ÷ 0.75 mol.
χ(He) = 0.33; mole fraction of helium.
p(He) = 0.33 · 0.48 atm.
p(He) = 0.158 atm; the partial pressure of the helium gas.
112 km is travelled by car in 60 minutes
1 km is travelled by car in 60/112 minutes
56 km is travelled by car in 60/112*56 = 30 minutes = 0.5 hours
Explanation:
The molecular formula : C₁₈H₁₈N₈
<h3>Further explanation</h3>
Given
62.41% C, 5.24% H, and 32.36% N
Required
The molecular formula
Solution
mol ratio
C : 62.41/12.0096 = 5.1967
H : 5.24/1.00784 = 5.1992
N : 32.36/14.0067 = 2.310
Divide by 2.310(smallest)
C : 5.1967/2.31=2.25
H : 5.1992/2.31 = 2.25
N : 2.31/2.31 = 1
Multiplied by 4
C : H : N = 9 : 9 : 4
The empirical formula : C₉H₉N₄
(C₉H₉N₄)n=346.40 g/mol
(12.0096 x 9 + 1.00784 x 9 + 14.0067 x 4)n=346.4
(108.0864+9.07056+56.0268)n=346.4
(173.184)n=346.4
n=2
<em>The molecular formula : C₁₈H₁₈N₈</em>
Answer:
156 g
Explanation:
Let's consider the following reaction.
2 NaN₃(s) → 2 Na(s) + 3 N₂
(g)
We can find the moles of N₂ using the ideal gas equation.
P × V = n × R × T
1.50 atm × 60.0 L = n × (0.08206 atm.L/mol.K) × 305 K
n = 3.60 mol
The molar ratio of N₂ to NaN₃ is 3:2. The moles of NaN₃ are:
3.60 mol N₂ × (2 mol NaN₃ / 3 mol N₂) = 2.40 mol NaN₃
The molar mass of NaN₃ is 65.01 g/mol. The mass of NaN₃ is:
2.40 mol × 65.01 g/mol = 156 g
