Balance Equation :)

Question

Hello, 

I have a little bit problem at understanding this lesson (( Balance Equation )) 

here is some of the Question I need help with them...

 

Fill the missing boxes with numbers:

 

Q1) (?)NaOH + H₂SO₄ ---->  Na₂ SO₄ + (?)H₂O 

 

Q2) how do I know if this is 1mole or 2.. i mean what does it means if the word ends with: ide/ine 

 

Q3) Use your knowledge of reactivity to explain why the reaction happens? ((i hope you make it as simple is possible)) :)

 

So these are the Question.. Thank you For YOUR TIME!! 

Answer 1

Q1) I like to think of balancing as if it were a simple math problem. x= x

so we can make a table with all of the different atoms (I keep the polyatomic ions together if they are the same on both sides of the equation)

                Reactants       Products  

Na                 1                     2

O                   1                     1

H               1+2 =3                2 

(SO4)^-2       1                     1

 

So the oxygen and sulfate are balanced, but not the sodium or hydrogen

So I will add a 2 in front of sodium hydroxide

 

(2)NaOH + H2SO4 ----> Na2 SO4 + (?)H2O

                 Reactants           Products
Na                 2                         2
O                   2                         1
H               2+2 =4                    2
(SO4)^-2        1                         1

 

We have sodium balanced, but now oxygen is not neither is hydrogen

So I will add 2 on the product side in front of water

(2)NaOH + H2SO4 ----> Na2 SO4 + (2)H2O

 

 

              Reactants             Products
Na                2                         2
O                 2                         2
H              2+2 =4                2x2=4 
(SO4)^-2       1                         1

 

Now we have a balanced chemical equation

 

Q2) This seems like two separate questions. First we can say the coefficients are the number of moles (the numbers in front of the molecules in the chemical equation. The values we added to make the equation balanced.) This is what is referred to as the mole ratio, in other words for every 2 moles of sodium hydroxide, 1 mole of sodium sulfate is produced. 

 

The other part of your question is about naming the different molecules. When the molecule is elemental (only 1 type of atom like O2 or F2), you keep the name from the periodic table. When the molecule has more than one atom then you add -ide to the end of the anion (the negative atom). This does not happen in the case of a polyatomic ion and you will just have to memorize those. So that is the case with ionic bonding (cation and anion), for example HF is hydrogen fluoride. The hydrogen doesn't change but the ending of fluorine does. 

 

For covalent bonding, the last atom listed gets a change in the ending (CO2 is Carbon dioxide). Notice also that the atom has a prefix. 

 

Q3) This is a reaction between an acid and a base, which we know as a neutralization reaction. 

Acid  + Base -> salt + water

How do I know this is an acid and Base? The extra hydrogen will combine the hydroxide to form water. 

This is also a double displacement reaction. 

We could calculate the gibbs free energy to determine if this reaction can happen spontaneously (ΔG is negative).

ΔG = ΔH - T ΔS

These values are found in tables. (ΔH = change in enthalpy, ΔS = change in entropy, T is the temperature in Kelvin)

 

Answer 2

Q1 - You have to "balance" the equation by determining what coefficients would balance the numbers of each individual atom.  Both molecules on both sides have Oxygen (O), so I look to the Sodium (Na) to help me determine the coefficients.  

 

I see that I have 2 sodium on the right, which means my coefficient on the left must be a multiple of 2.  Then I check to see if that balances everything.  

 

(2)NaOH + H₂SO₄ ----> Na₂SO₄ + (?)H₂O

 

I would have a total of 2 Na on both sides, 6 O on the left but only 5 on the right.  This means I would have to multiply the H₂O by 2 to get the extra Oxygen, so the coefficient on the right is now 2.

 

(2)NaOH + H₂SO₄ ----> Na₂SO₄ + (2)H₂O

 

Now I look again.  

 

2Na on both sides, 6 O on both sides, 4 H on both sides, 1 S on both sides.  

 

Equation is balanced.

 

Q2 - A mole is a unit of measurement.  Like saying "1 liter of soda" vs "2 liters of soda".  That doesn't really relate to Q1, as Q1 just shows the ratios.  You CAN use the periodic table to determine how many atoms of each element would be in a given mass.  [I think that is called "molar mass".]  

 

-ide is used for naming the anion of an ionic compound.  It is for non-negative ions (gain electrons), non-metals

 

Elemental Sodium and Chlorine become Sodium Chloride.

 

Q3 - NaOH is Sodium Hydroxide, H₂SO₄ is Hydrogen Sulfate (sulfuric acid), Na₂SO₄ is Sodium Sulfate, and H₂O is Hydrogen Oxide (water).  This is combining a strong acid and strong base.  The result will be a lot of heat energy (like, potentially explosive), and sodium sulfate dissolved in water.