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 = $e^{-2.54738}$

= 0.078286

Therefore, the required constant (k2) = 0.078286 * 0.000717 = $5.61*10^-^5$

6 0

3 years ago

Calculate the change in temperature (ΔT) that occurs when 8000 J of energy (q) is used to heat up a mass (m) of 75 g of water. (

pickupchik [31]

Answer:

The change in temperature that occurs when 8000 J of heat is used by a mass 75 g of water is 25.4 °C

Explanation:

H = mc ΔT

m = 75 g

c = 4. 200 J/ g °C

H = 8000 J

ΔT =?

Rearranging the formula, making ΔT the subject of formula;

ΔT = H / m c

ΔT = 8000 / 75 * 4.200

ΔT = 8000 / 315

ΔT = 25.4 °C

8 0

4 years ago

Read 2 more answers