NaCl is salt to it is obviously SOLUBLE :)
Answer: 
Explanation: A double displacement reaction is one in which exchange of ions take place.
The compounds which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
Thus the exchange of ions take place and all the compounds are soluble so the chemical formulas are followed by the symbol (aq).
Answer:
Approximately
.
Explanation:
The gallium here is likely to be produced from a
solution using electrolysis. However, the problem did not provide a chemical equation for that process. How many electrons will it take to produce one mole of gallium?
Note the Roman Numeral "
" next to
. This numeral indicates that the oxidation state of the gallium in this solution is equal to
. In other words, each gallium atom is three electrons short from being neutral. It would take three electrons to reduce one of these atoms to its neutral, metallic state in the form of
.
As a result, it would take three moles of electrons to deposit one mole of gallium atoms from this gallium
solution.
How many electrons are supplied? Start by finding the charge on all the electrons in the unit coulomb. Make sure all values are in their standard units.
.
.
Calculate the number of electrons in moles using the Faraday's constant. This constant gives the size of the charge (in coulombs) on each mole of electrons.
.
It takes three moles of electrons to deposit one mole of gallium atoms
. As a result,
of electrons would deposit
of gallium atoms
.
Hello!
The number of 20-g ice cubes required to absorb 47 kJ from a glass of water upon melting is 7 icecubes
Why?
We are going to clear from the equation of the released heat, the mass of ice (m). The specific latent heat of fusion of ice is 336 kJ/kg:

So, 7 ice cubes are required to absorb that amount of heat from the glass of water.
Have a nice day!
There should be mass balance and the charge balance between the reactants and the products
Mass balance : total no of individual atoms of each type should be balanced before and after the reaction
Charge balance : Overall charge of the reactants should be balanced with the overall charge of the products
You can balance,
1)by just looking at it
2)by Algebraic method given above or
3)by the redox method
You need to know how to get the oxidation numbers in order to use the oxidation method