Writing Chemical Equations in Words

Writing Chemical Equations in Words


Professor Dave here, let’s learn how to
write chemical equations. We know a little bit about chemical reactions,
as well as the written equations we can write to depict them. But there are a few different ways we can
write these equations. We should be able to write them using chemical
formulas, which abbreviate all the elements present in each compound, and sometimes list
the phases of each compound, but we should also be able to write these equations using
words, because this helps us understand how we might verbally communicate the details
of a chemical reaction to someone else. Let’s therefore make sure that we can do
two things. We must be able to look at a chemical reaction
that is written with symbols, and translate it into written words. And we must also be able to do this in reverse,
by taking a sentence that describes a chemical reaction, and making sure we are able to display
this transformation using the symbols we know in chemistry. Take this reaction for example. We have NA solid plus H2O on the reactants
side and then NaOH in the aqueous phase and H2 in the gas phase. Let’s turn this equation into a sentence
comprised of normal words. Starting from the left, NA is sodium, and
it’s a solid, so we might simply say solid sodium metal. Now what does the sodium react with? We all know H2O is water, and the L means
liquid, so let’s add “reacts with liquid water”. Now the forward arrow separates the reactants
from the products, so we need words that indicate that a chemical reaction has occurred. So let’s say “to produce”. And now we list the products. NaOH is sodium hydroxide, and it’s in the
aqueous phase, so we write aqueous sodium hydroxide, and H2 is hydrogen, which is a
gas, so we write hydrogen gas. And now we have completed a sentence that
describes in words what the equation describes in symbols. Let’s go the other way around. Say we have the following sentence. Solid iron reacts with fluorine gas to produce
solid iron three fluoride. Let’s identify some key words here. “Reacts with” tells us that iron and fluorine
are the reactants, and “produce” tells us that iron three fluoride is the product. So those should be separated by an arrow. Now let’s translate the words into chemical
symbols and phase symbols. The symbol for iron is Fe, and it’s a solid,
so let’s write Fe with the subscript S in parentheses. Then we put a plus symbol, because the iron
is reacting with something else. Fluorine has the symbol F, and fluorine gas
is F2, which we know from our ability to draw Lewis dot structures. So let’s write F2 with the subscript G in
parentheses. Then the forward arrow, separating the reactants
from the products, and lastly we have iron three fluoride. So we know the product has iron and fluorine
in it, but in what ratio? If we recall, this roman numeral three is
telling us the oxidation state of the iron atom, which will be plus three. Fluoride ions are minus one, so we will need
one iron and three fluorides to make a neutral molecule, so we write FeF3 with the subscript
S. Lastly, we might want to balance the equation. We can see that we have two fluorines on the
left and three on the right, so let’s put a three here and a two there so that we have
six on each side. Now we also have two irons on the right, so
let’s put a two here so that we have two irons on the left as well. And that’s all there is to it, so we should
now be able to write chemical equations either with symbols or with words. Let’s check comprehension.

13 thoughts on “Writing Chemical Equations in Words

  • September 19, 2018 at 3:30 pm
    Permalink

    Oh man! At 0:40 I wrote "water and oxygen react to form water". What a silly mistake. Of course it should be "hydrogen and oxygen react to form water". Please forgive me!

    Reply
  • March 20, 2019 at 10:39 am
    Permalink

    when people hear your voice but then look at the way you speak _

    Reply
  • March 26, 2019 at 1:44 am
    Permalink

    goodness thank you,
    much clarification!

    wish me luck, i have
    an upcoming test–
    several in the future.
    (⊙_⊙)

    Reply
  • March 26, 2019 at 2:56 am
    Permalink

    playin silly buggers with me!

    Reply
  • April 24, 2019 at 4:13 am
    Permalink

    Who's the one person that disliked the video?

    Reply
  • June 14, 2019 at 1:54 pm
    Permalink

    Hi

    Reply
  • August 19, 2019 at 2:05 am
    Permalink

    Good lecture .

    Reply
  • August 24, 2019 at 5:45 pm
    Permalink

    You look like ranbir kapoor

    Reply
  • November 11, 2019 at 9:43 am
    Permalink

    Ye kya hai

    Reply
  • December 6, 2019 at 2:25 pm
    Permalink

    Thank you, I do a Science course and this has helped a lot with my recent assignment.

    Reply
  • December 29, 2019 at 3:35 pm
    Permalink

    ©©

    Reply
  • December 29, 2019 at 3:35 pm
    Permalink

    ©©

    Reply
  • January 23, 2020 at 1:17 am
    Permalink

    Saved me man

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *