Answer:
Explanation:
Use one of your experimentally determined values of k, the activation energy you determined, and the Arrhenius equation to calculate the value of the rate constant at 25 °C. Alternatively, you can simply extrapolate the straight line plot of ln(k) vs. 1/T in your notebook to 1/298 , read off the value of ln(k), and determine the value of k. Please put your answer in scientific notation. slope=-12070, Ea=100kJ/mol, k= 0.000717(45C), 0.00284(55C), 0.00492(65C), 0.0165(75C), 0.0396(85C)
Explanation;
According to Arrhenius equation:
i.e. ln(k2/k1) = -Ea/R (1/T2 - 1/T1)
Where, k1 = 0.000717, T1 = 45 oC = (45+273) K = 318 K
T2 = 25 oC = (25 + 273) K = 298 K
i.e. ln(k2/0.000717) = -12070 (1/298 - 1/318)
i.e. ln(k2/0.000717) = -2.54738
i.e. k2/0.000717 = 
= 0.078286
Therefore, the required constant (k2) = 0.078286 * 0.000717 = 
For this question, assume that you have 1 compound. This compound is divided in half once, so you are left with 0.5. That 0.5 that remains is divided in half again, this is the second half-life, and you are left with 0.25. The final half life involves dividing 0.25 in half, which means you are left with 0.125. For the answer to make sense, you need to know your conversions between decimals and fractions. To make it simple, if you have 0.125 and you times it by 8, you are left with your initial value of 1. Therefore, after three half-lives, you are left with 1/8th of the compound.
Answer:
hot air rises because gases expand as they heat up.When air heats up and expands,its density also increases.The warmer,less dense air effectively floats on top of the colder, dense air below it. This creates a buoyant force that causes warmer air to rise.
cold air sinks because it is heavier as its more dense ( because of closely packed molecules) soits harder for them to move and they absorb less energy. Also, gravity pulls on it more strongly.
Hope it helps :)
Answer:
National fire protection Association
Explanation:
the nfpa is a global self funded nonprofit orgnazation establised in 1896 devoted to eliminating death injury protery loss and ecomomic loss due to fire and electrical hazards
