[Hello411]

I know it si HNO3 Na = NaN03 H2

But how do I balance it please

[Chic_Bowdrie]

i know it si HNO3 Na = NaN03 H2

But how do i balance it please

Your reaction is probably HNO3 + Na => NaN03 + H2. There are general rules for balancing chemical equations and some are so complicated that following the rules is crucial. This equation is not like that. The main thing to notice is the primary elements N and Na are already balanced. So is O. All you have to do is insert 1/2 in front of the H2 and the equation balances. Its OK to multiply both sides by 2 and express the final answer as 2HNO3 + 2Na => 2NaNO3 + H2

[Hello411]

Thanks but the problem is I never understand when you are suppose to cross valency basically I am not getting chemistry at all especially moles.

[Chic_Bowdrie]

It is hard to balance equations if you don't know the valences involved. To know the valences you have to learn the characteristics of the reactants and products. In this problem NO3 has a net valence of -1 and it does not change during the reaction. The Na ion is losing an electron and its valence goes from 0 to +1. To balance, H is originally +1 but picks up the electron from the Na and goes to a valence of 0. The coefficient of 2 is needed because H is normally combined as a diatomic molecule.

I guess this is one reason Chem is hard. There is no short cut. You have to figure out the valences of the components in the reaction to balance it.

[Hello411]

Thanks

[SHALEEN MEHTA]

HNO3 + Na = NaNO3 + H2O IS IT CORRECT?

[Chic_Bowdrie]

No, Shaleen, it is not.

Na and NO3 are combining in a single replacement oxidation-reduction reaction. There is no source of any further O available to create a H2O molecule. Na is oxidized to Na+ and H+ is reduced to H2. The valence of H in H2O is still +1.

[ChicBOOM]

But there is this property of a metal which says that only magnesium and manganese react with VERY DILUTE NITRIC ACID to liberate Hydrogen gas. Other metals react with nitric acid to liberate nitric oxides such as nitorgen monoxide or dinitrogen monoxide or nitrogen dioxide. That is particularly why I was confused.

[ma0641]

But there is this property of a metal which says that only magnesium and manganese react with VERY DILUTE NITRIC ACID to liberate Hydrogen gas. Other metals react with nitric acid to liberate nitric oxides such as nitorgen monoxide or dinitrogen monoxide or nitrogen dioxide. That is particularly why I was confused.

ONLY Mg and Mn? ANY metal ABOVE hydrogen in the activity series will liberate hydrogen with VERY DILUTE HNO3. Google "reactivity series of metals" and you will see where hydrogen fits.

[kreysiz]

Na is a metal with valency = 1
HNO3 is a monobasic acid
thus, the reaction between them will be in the molar ratio of 1:1.
Provide your solution for further details.