Answer:
To increase surface area of the platinum electrode which results in superior quality and action of the electrodes as opposed to normal platinum electrodes.
Explanation:
Platinization of Platinum is the process of covering platinum electrode with a layer of platinum black. Platinum black is a finally divided form of platinum, optimized for catalysing the addition of hydrogen to unsaturated organic compound. This increases the surface area of the platinum electrodes and therefore exhibits action superior to that of normal electrodes.
Answer: The correct option is A.
Explanation: Chemical reaction is defined as the reaction when there is a formation of new substance. Indicators that help in determining the chemical reaction are:
- Change in Temperature
- Appearance or disappearance of color
- Formation of bubbles
- Formation of a precipitate
- Characteristic odor
Option A: As seen from the image, there is a color change happening in the event. So, it can be considered as a chemical reaction.
Option B: In Event 1, release of heat and light is not visible. Hence, this is not the indicator for detection of chemical reaction.
Option C: In Event 2, we cannot judge the dropping of temperature just by seeing the image. Hence, this cannot be considered as a chemical reaction.
Option D: In this, the color is not mixed throughout the liquid, which means they are not reacting and hence, is not the indicator for chemical reaction.
Therefore, option A is the correct answer.
The potassium chloride is KCl. The gram formula mass of KCl is 39+35.5=74.5 g/mol which means 74.5 g per mole of KCl. So the mass of KCl is 6.90*74.5=514 g.
Answer:
the relationship between mass and volume
The answer is: Dividing the number of molecules in the sample by Avogadro's number.
The Avogadro’s number is the number of atoms in 12 grams of the isotope carbon-12 (¹²C).
Na is Avogadro number or Avogadro constant (the number of particles, in this example carbon, that are contained in the amount of substance given by one mole).
The Avogadro number has value 6.022·10²³ 1/mol in the International System of Units; Na = 6.022·10²³ 1/mol.
For example:
N(Ba) = 2.62·10²³; number of atoms of barium.
n(Ba) = N(Ba) ÷ Na.
n(Ba) = 1.3·10²⁴ ÷ 6.022·10²³ 1/mol.
n(Ba) = 2.158 mol; amount of substance of barium.