The activation energy of a reaction is the minimum energy that must be overcome in order for the reaction to take place. One way of reaching the activation energy is by manipulating the process conditions like pressure or temperature. But the most common method is by adding an enzyme. An enzyme speeds up the rate of the reaction but does not actively take part in it.
An analogy would be pushing heavy wooden block down a slope. No matter how many people push on it, the block won't move because of friction. But if you spill oil on the floor, the block would effortlessly move down the slope. The oil here is like an enzyme in a reaction.
333,000 Joules is the amount of energy (heat) in joules required to raise the temperature of 5 kg of iron from 50°C to 200°C.
Explanation:
Data given:
mass of iron 5 Kg or 5000
initial temperature = 50 degree centigrade
final temperature = 200 degrees centigrade
change in temperature (Δ T= 200 -50 degrees centigrade)
= 150 °C
cp (specific heat capacity of iron) = 0.444j/gram C
q (heat supplied) = ?
applying the formula,
q=mcΔT
putting the values in the equation:
q = 5000 X 0.444 X150
q = 333,000 Joules of energy.
The heat required 333,000 Joules of energy is required.
An acidic solution would turn a blue litmus paper red due to the mobile and free hydrogen (H+) ions. These hydrogen ions affect the colour property of the litmus papers and thus the colour change. A litmus paper dropped into a solution of hydrogen ions turns red to indicate that the solution is acidic.
The car stopped due to a gravitational pull (gravity slowing it down) the energy is converted to kinetic energy and heat energy.
