The answer is (3) 3. The calculation rule of significant figures is when multiplication and division, the significant figures of result is equal to the least of the numbers involved. The significant figure of 2.70 and 80.01 is 3 and 4.
Answer:
a. 113 min
Explanation:
Considering the equilibrium:-
2N₂O₅ ⇔ 4NO₂ + O₂
At t = 0 125 kPa
At t = teq 125 - 2x 4x x
Thus, total pressure = 125 - 2x + 4x + x = 125 - 3x
125 - 3x = 176 kPa
x = 17 kPa
Remaining pressure of N₂O₅ = 125 - 2*17 kPa = 91 kPa
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given that:
The rate constant, k =
min⁻¹
Initial concentration
= 125 kPa
Final concentration
= 91 kPa
Time = ?
Applying in the above equation, we get that:-

Answer:
C Fossil fuels will run out soon
Answer:
easy
Explanation:
In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.
The heat will flow from copper to aluminum because Cu is at higher temperature. The heat liberated is -7.60kJ
When two metals at different temperatures are kept in contact, heat flows from hotter metal to colder metal until thermal equilibrium is reached.
Here Copper is at a temperature of 60 degree Celsius and aluminum is at 40 degree Celsius. Thus, heat will flow from Cu to Al.
In order to calculate the amount of heat liberated following calculations are required.
m1=262 g
T1=87 oC
Cp=0.385 J/g oC
T2=11.8 oC
The heat liberated can be expressed as follows:
Q=mCp(T2-T1)
Q=262 g*0.385 J/goC(11.8-87)oC
Q=-7585 J
=-7.60kJ
To learn more about heat check the link below:
brainly.com/question/13439286
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