Answer:
the wheels and force of your foot pushing off of the ground.
Answer:
Colours come from electrons moving between shells. The energy of light matches the energy gaps between electron shells.
Explanation:
Electrons are arranged in energy levels (shells) and there are energy gaps between shells. Electrons must be in one shell and cannot be in between. Electrons can move from one shell to another in the right conditions.
When an atoms absorbs energy from heat or light, the atom starts to move a little faster, in other words, it gets warmer. If the energy absorbed is just right to match the energy gap between shells, electrons can jump from one shell to another.
If an object is red, then the energy between gaps during light absorption is equal to the energy of the complementary light color, green.
If the object emits red light, then the energy between gaps during light emission is equal to the energy of red light.
Answer:
The correct option is;
The reaction pathway for the trials is different
Explanation:
The effect of a catalyst in a chemical reaction is to increase the rate of a reaction by changing the pathway or mechanism of the reaction and/or to lower the transition state's energy thereby lowering the activation energy of the reaction
The pathway of the reaction is changed by the catalyst by the formation of intermediate compounds by the catalyst which require lower activation energy to form the products than the original non-catalyzed reactants. In the process the catalyst is regenerated, thereby, not taking part in the reaction.
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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%
