A reaction is first order. If the initial reactant concentration is 0.0200 M, and 25.0 days later the concentration is 6.25 x 10-4 M, then its half-life is:
The molecules and atoms vibrate faster. As atoms vibrate faster the space between atoms also increases.
Answer:
DECREASE BY A FACTOR OF FOUR
Explanation:
Using pressure equation:
P 1 / T1 = P2 /T2 (at constant volume)
P1 = P
T1 =T
P2 = ?
T2 = 4 T
So therefore;
P2 = P1T1/ T2
P2 = P T/ 4 T
P2 = 1/4 P
The pressure is decreased by a factor of four, the new pressure is a quarter of the formal pressure of the gas.
Explanation:
Activation energy, in chemistry, is the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport. Basically, activation energy is that push that atoms need in order to undergo reactions.
All chemical reactions, including exothermic reactions, need activation energy to get started. Activation energy is needed so reactants can move together, overcome forces of repulsion, and start breaking bonds.
A catalyst lowers the activation energy of a reaction, so that a chemical reaction can take place. Increasing the temperature of a reaction has the effect of increasing the number of reactant particles that have more energy than the activation energy. Enzymes are a form of catalysts that speed up chemical reactions by lowering the activation energy.
The correct options are therefore;
- is decreased in the presence of an enzyme specific for that reaction.
- is the amount of free energy required to bring the reactants to the transition state.
- is an alternative term for the free energy of activation.
Answer:
Explanation:
3 )
18 grams of water contains 16 grams of oxygen .
Let the grams of oxygen needed be m .
yield is 75%
Only 75 % of m will make water .
.75 m will form water .
water formed by .75 m of oxygen = 18 / 16 x .75 m
Given that
18 / 16 x .75 m = 79
m = (16 x 79) / ( 18 x .75 )
= 93.63 grams .
So oxygen required is 93.63 grams .
4 )
One mole of water contains 0.5 moles of oxygen.
2 moles of oxygen will make 2 /,5 = 4 moles of water .
percent yield is 82 % ,
so water produced = .82 x 4 = 3.28 moles of water.
