Potassium is an alkali metal with the chemical symbol K. It has an atomic number of 19, meaning that it has 19 positively charged protons. It also contains 19 electrons, which have a negative charge, and 20 neutrons, which do not hold a charge
Hope this help
Answer:
3
Explanation:
The mass has 4 sig digits.
The volume has 3 sig digits
The density is = 11.50/9.03 = 1.2735
To 3 sig digits (determined by 9.03) the answer would be 1.27 gram/mL
Here is the correct question:
The reaction A → products was studied at a series of different temperatures. A plot of ln(k) vs. 1/T gave a straight line relationship with a slope of -693 and a y-intercept of -0.425. Additionally, a study of the concentration of A with respect to time showed that only a plot of 1/[A] vs. time gave a straight line relationship. What is the initial rate of this reaction when [A] = 0.41 at 271 K ?
Answer:
the initial rate of this reaction is 0.0216275 M/sec
Explanation:
Using the formula:
![K = Ae^{\frac{-Ea}{RT}}](https://tex.z-dn.net/?f=K%20%3D%20Ae%5E%7B%5Cfrac%7B-Ea%7D%7BRT%7D%7D)
![InK = InA + (\frac{-Ea}{R})(\frac{1}{T})\\y \ \ \ \ \ \ \ \ \ \ c \ \ \ \ \ \ \ \ \ \ m \ \ \ \ x](https://tex.z-dn.net/?f=InK%20%3D%20InA%20%2B%20%28%5Cfrac%7B-Ea%7D%7BR%7D%29%28%5Cfrac%7B1%7D%7BT%7D%29%5C%5Cy%20%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%20%5C%20%5C%20%5C%20c%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20m%20%20%5C%20%5C%20%5C%20%5C%20x)
![= -693](https://tex.z-dn.net/?f=%3D%20-693)
![\frac{Ea}{8.314}= 693 \ \\ \\ Ea = 693 * 8.314 \\ \\ Ea = 5671.602 \ J](https://tex.z-dn.net/?f=%5Cfrac%7BEa%7D%7B8.314%7D%3D%20693%20%5C%20%5C%5C%20%5C%5C%20Ea%20%3D%20693%20%2A%208.314%20%5C%5C%20%5C%5C%20Ea%20%3D%205671.602%20%5C%20J)
![In A = -0.425 \ \ \\ \\ A = e^{-0.425} \\ \\ A = 0.6538](https://tex.z-dn.net/?f=In%20A%20%3D%20-0.425%20%5C%20%5C%20%5C%5C%20%5C%5C%20%20A%20%3D%20e%5E%7B-0.425%7D%20%5C%5C%20%20%20%5C%5C%20%20A%20%3D%200.6538)
![K = 0.6538 e^{- (\frac{5761.602}{8.314*271})](https://tex.z-dn.net/?f=K%20%3D%200.6538%20e%5E%7B-%20%28%5Cfrac%7B5761.602%7D%7B8.314%2A271%7D%29)
![K = 0.05275 \\ \\ K = 5.275*10^{-2}](https://tex.z-dn.net/?f=K%20%3D%200.05275%20%5C%5C%20%5C%5C%20K%20%3D%205.275%2A10%5E%7B-2%7D)
Since
vs time is a straight line relationship;
Therefore, it is a second order reaction
rate = K[A]²
rate = 5.275 × 10⁻² × (0.41)
rate = 0.0216275 M/sec
Answer:
Calcium chloride cannot melt the ice at -20°C. Cryoscopy is the method of determining a decrease in melting point due to dissolved substances.
Radio waves because they have the longest wavelength and gamma waves because they have the shortest wavelength.