Answer:
Energy of photon is 34.45 ×10⁻¹⁹ J.
Explanation:
Given data:
Frequency of photon = 5.2×10¹⁵ s⁻¹
Plancks constant = 6.626×10⁻³⁴ Js
Energy of photon = ?
Solution:
Formula:
E = h.f
by putting values,
E = 6.626×10⁻³⁴ Js × 5.2×10¹⁵ s⁻¹
E = 34.45 ×10⁻¹⁹ J
Thus, energy of photon is 34.45 ×10⁻¹⁹ J.
the answer to the first one is D and the second one is the first one
Answer:
Percent yield = 57%
Explanation:
Given data:
Mass of nitrogen = 15.0 g
Mass of hydrogen = 15.0 g
Mass of ammonia produced = 10.5 g
Percent yield = ?
Solution:
Chemical equation:
N₂+ 3H₂ → 2NH₃
Number of moles of hydrogen:
Number of moles = mass/molar mass
Number of moles = 15.0 g/ 2 g/mol
Number of moles = 7.5 mol
Number of moles of nitrogen:
Number of moles = mass/molar mass
Number of moles = 15.0 g/ 28 g/mol
Number of moles = 0.54 mol
Now we will compare the moles of ammonia with nitrogen and hydrogen from balance chemical equation.
N₂ : NH₃
1 : 2
0.54 : 2×0.54 = 1.08
H₂ : NH₃
3 : 2
7.5 : 2/3×7.5= 5 mol
Theoretical yield of ammonia:
Mass = number of moles × molar mass
Mass = 1.08 × 17 g/mol
Mass = 18.36 g
Percent yield:
Percent yield = (actual yield / theoretical yield) ×100
Percent yield = (10.5 g/ 18.36 g) ×100
Percent yield = 0.57 ×100
Percent yield = 57%
To find the density you need to divide mass by volume. When you divide 15g by 14cm^3, you get a density of 1.071g/cm^3. This matches the density of magnesium, so the unknown metal is magnesium.
Answer: False
Explanation: False, what if its in space?
