The answer is A.( The reaction is endothermic) I had it on my test and got it right
Answer:
Energy cannot be created or destroyed.
Explanation:
According to the law of conservation of energy, energy can neither be created nor it can be destroyed. Energy can only be transformed from one matter to another. The conservation of energy remains constant in an isolated system. The law is applicable in the system that does not exchange energy in the environment. Energy changes its form but remains constant.
Answer:
by providing an alternative pathway with a lower activation energy
Explanation:
Cataysts are the substances that neither consumed nor produced during a chemical reaction, but increase the rate of the reaction.
So, catalysts remain chemically unchnaged after the completion of the reaction.
For a reaction to occur, reactants molecule must collide and successful collisions lead to product formation.
A certain minimum amount of energy is required for successful collision. This minimum amounr of energy is called activation energy.
One way to increase speed of reaction is to provide energy to the reactants and other way to increase speed is to provide alternate pathway with lower activation energy.
Catalyst increases a rate of reaction by providing an alternate pathway with lower activation energy.
Therefore, the correct option is option b 'by providing an alternative pathway with a lower activation energy'
Answer:
Frequency = 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻²⁰KJ
Explanation:
Given data:
Wavelength of light = 630.0 nm (630 × 10⁻⁹ m)
Frequency of light = ?
Energy in joule = ?
Solution:
speed of light = wavelength × frequency
Frequency = speed of light / wavelength
Frequency = 3 × 10⁸ m/s / 630 × 10⁻⁹ m
Frequency = 0.005× 10¹⁷ s⁻¹
Energy:
E = h. f
E = 6.63× 10⁻³⁴ Kg. m²/s × 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻¹⁷ j
E = 0.03 × 10⁻¹⁷ j×1 kj /1000 j
E = 0.03 × 10⁻²⁰KJ
Answer:
3.3 cm³
Explanation:
Use the density formula, d = m/v, to solve for the volume:
2.7 = 9.0/v
2.7v = 9.0
v = 3.3 cm³
