Chlorine gas reacts with sold sodium to form solid sodium chloride Write a balanced chemical equation?

2 Answers
May 18, 2018

#Na(s) + 1/2Cl_2(g) rarr NaCl(s)#

Explanation:

That is the the stoichiometric equation....normally, we would give the metal a good roasting to get it volatile and able to react with the chlorine gas.. The overall reaction is exothermic...

May 18, 2018

#2Na_((s)) + Cl_(2(g)) -> 2NaCl_((s))#

Explanation:

  • Chlorine (#Cl_(2)#) is most often seen in these types of problems as a gaseous substance (hence the little " g " on its subscript
  • Sodium (#Na#) is most often seen in its solid form (as a reactant)
    in basic chem. problems like this as well (hence the little " s "
    on its subscript)
  • If we combine these two we get table salt (#NaCl#) which itself is a solid substance.

Here is the general equatioon of how a Metal (#M#) will react with a nonmetal (#X#) to form an Ionic Compound (#MX#)
#color(red)(M+X->MX)#

With all that said we have...
#Na_((s)) + Cl_(2(g)) -> NaCl_((s))#

BUT...We have to balance it!

Remember moles are coefficients, if you could see them it'd look something like this...

#color(red)(1) Na_((s)) + color(red)(1) Cl_(2(g)) -> color(red)(1) NaCl_((s))#

You have 1 mole of #Na# on the left
You have 1 mole of #Cl# on the left
You have 1 mole of #NaCl# on the right

Remember atoms are subscripts, such as the #2# in #Cl_(2)#
You have 1 atom of #Na# on the left
You have 2 atoms of #Cl# on the left
You have 1 atom of #NaCl# on the right

These atoms should always be balanced with the moles on both sides. To do this we put those numbers (# of moles) in the coefficients!

So "balancing" this would give us...

#color(red)(2)Na_((s)) + color(red)(1)Cl_(2(g)) -> color(red)(2)NaCl_((s))#

If confused at all or need any more practice, this video is extremely helpful for learning how to balance basic chemical equations: