The number of significant figures within a number are the amount digits that are required to specify a number to a certain degree of accuracy. In the number, 0.0645 g, the 6 is the most significant figure and 4 is the second most significant figure. Therefore, rounding to two significant figures yields 0.064g.
Think of it this way: it is a distribution problem in which you are multiplying the 2 on the outside with each element in the parentheses. Oxygen does not have a number in front of it, so put an imaginary one in front of it to help you. Do the same with Hydrogen since it doesn't have a number in front of it either. Now you know that hydrogen has one ion and oxygen has one... but you must now multiply each of the elements' ions by two. You should now know that Oxygen has 2 ions in Calcium Hydroxide and that there are also 2 ions of Hydrogen in Calcium Hydroxide. Does this make sense?
Answer:
The value is 
Explanation:
From the question we are told that
The equation is 
The temperature is ![T = 25^oC = 298 K [room \ temperature ]](https://tex.z-dn.net/?f=%20T%20%3D%2025%5EoC%20%3D%20%20298%20K%20%20%20%5Broom%20%20%5C%20temperature%20%5D)
The emf at standard condition is 
Generally at the cathode
At the anode
Generally for an electrochemical reaction, at room temperature the Gibbs free energy is mathematically represented as
Here n is the no of electron with value n = 6
F is the Faraday's constant with value 96487 J/V
=> 
=> 
This Gibbs free energy can also be represented mathematically as
Here R is the cell constant with value 8.314J/K
K is the equilibrium constant
From above
=> 
Generally antilog = 2.718
=>
=>
That would be ionic lattice.
molecules can be made of two of the same elements whereas a compound is always made of two different elements
