A first-order reaction is 81omplete in 264s.The half-life for this reaction (i) t 1/2 = =3.465×10 −3 s.to reach 95% Completion = 285 s.
To measure reaction rates, chemists initiate the reaction, measure the concentration of the reactant or product at different times as the reaction progresses,
For a 0-order response, the mathematical expression that may be employed to determine the half of life is: t1/2 = [R]0/2k. For a first-order reaction, the half of-existence is given by: t1/2 = zero.693/ok. For a 2d-order response, the method for the half-life of the response is: 1/okay[R]0
The 1/2-life of a response (t1/2), is the quantity of time needed for a reactant concentration to lower via half of compared to its initial awareness. Its software is used in chemistry and medicine to are expecting the awareness of a substance over time
Half of the lifestyles is the time required for exactly 1/2 of the entities to decay 50%.
Learn more about first order reaction here:-
#SPJ4
Answer:
He is wrong . Most accurate is Buret .
Explanation:
The number of significant figure denotes the level of accuracy of a measurement .
Beaker can measure liquid in mL upto significant figure of 2 . That means it can measure volume in terms of 10 , 20 , 30mL etc . It can not measure 25 mL
accurately . The last figure of 28 mL is read by guess in the question . So it is not an accurate measurement .
Similarly , graduated cylinder can measure liquid upto significant figure of 3 . That means it can measure volume in terms of 11 , 22 , 33 mL etc . It can not measure 25.5 mL accurately . The last figure of 28.3 mL is read by guess in the question . So it is less accurate measurement .
Similarly , buret can measure liquid upto significant figure of 4 . That means it can measure volume in terms of 11.2 , 22.3 , 33.5 mL etc . It can not measure 25.53 mL accurately . The last figure of 28.32 mL is read by guess in the question . So it is most accurate among all the three instrument because it can measure accurately mL upto one tenth of it .
Answer: The gravitational pull on Moon B is greater than on Moon A because Moon B is closer to the new planet than Moon A.
Explanation:
The gravitational force exerted by the two objects on each other is inversely proportional to the square of the distance between the objects.

F = gravitational force or pull
G = gravitational constant on that planet
M = mass of the object-1
m = mass of object-2(Mass of Moon-A or Moon-B)
r = distance between two objects

With decease in distance 'r' the force between the object increases or vice versa.So, from this we can say that the gravitational pull on Moon-B is more than the gravitational pull on Moon-A because the Moon B is closer than the Moon-A from the new planet.
<span>Answer:
2 C8H18 + 25 O2 => 16 CO2 + 18 H2O
1.0 kg = 1000 g C8H18 = 1000 g / 114.2293 g/mole = 8.75 moles C8H18
8.75 moles C8H18 produce (16/2) (8.75) = 70 moles CO2
70 moles CO2 = (70 moles) (44.0096 g/mole) = 3081 g CO2 = 3.1 kg CO2</span>