WHILE ARRANGING THE ELEMENTS, NEWLAND OBSERVED THAT ORDER HE SET WERE LIKE NOTES REPRESENTED AS THE SIGNS,THAT IS, EVERY FIRST NOTE IS EQUAL TO THE EIGHT ELEMENT, BUT HE COULD FIND ONLY 58 ELEMENTS THAT WERE CORRECTLY ORDERED IN HIS TABLE
Answer:
J.J. Thomson
Explanation:
According to my book and wiki, Historically, the mass of the electron was determined directly from combining two measurements. The mass-to-charge ratio of the electron was first estimated by Arthur Schuster in 1890 by measuring the deflection of "cathode rays" due to a known magnetic field in a cathode ray tube. It was seven years later that J. J.
Please correct me if I'm wrong.
Molar mass of ethanol is: 46 grams/moles
C2H6O-> 2x12 + 6x1+ 16x1 (see periodic table)
If 46 g correspond to 1 mol, how much moles correspond 35 g?
46g ====1mol
35g====x
x= 35/46
x=0,76 mol
-1367 kj/mol, means that there are -1367 kj in one mol
1mol ==== -1367 kj
0,76mol==== x
x=- 1040Kj
Ethanol released 1040 Kj.
Reaction of galvanic cell
<h3>Further explanation</h3>
Given
Redox reaction between Zn and Mg
Required
Half reaction
Potential of the cell
Solution
Zn²⁺ + 2e -> Zn E ° = -0.76 V
Mg²⁺ + 2e -> Mg E ° = - 2.37 V
The higher E ° of the cell will act as the positive pole/cathode
Electrode Zn as a cathode (reduction) and Mg as an anode (oxidation) (E ° of Zn cells is greater than Mg)
Half reaction
Cathode: Zn²⁺ + 2e ⇒ Zn E ° = -0.76 V
Anode: Mg ⇒ Mg²⁺ + 2e E ° = +2.37 V
------------------------------------------------- ----------- +
Cell reaction: Zn²⁺ + Mg ---> Zn + Mg²⁺ E ° cell = +1.61 V
The reaction occurs spontaneously in the absence of an electric current, thus including galvanic cells/voltaic cells
Answer:
B. The temperature of the water when the food sample has finished burning completely.
Explanation:
Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.
Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.
In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.
Energy can be calculated using the formula: Q = mc ∆T
where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).
The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.