Question

diatomic elements
when writing an equation, it is important to remember that some elements do not exist alone, but they pair up with other atoms of the same element. these are called diatomic elements. these are:
hydrogen (h₂)
oxygen (o₂)
nitrogen (n₂)
chlorine (cl₂)
bromine (br₂)
iodine (i₂)
fluorine (f₂)
remember these with the acronym: \brinclhof\
there are two other nonmetals you should remember too:
sulfur (s₈)
phosphorus (p₄)
practice
write an equation for each of the described reactions. include subscripts, and state of matter notation as needed. dont forget about the diatomic elements!

1. solid lithium reacts with liquid water to produce hydrogen gas and a solution of lithium hydroxide.
2. solid sodium reacts with gaseous chlorine to produce aqueous sodium chloride.
3. solid calcium carbonate breaks down into carbon dioxide gas, oxygen gas, and solid calcium.
4. solid iron(ii) sulfate and a solution of barium chloride react to form solid barium sulfate and a solution of iron (ii) chloride.
5. solutions of hydrochloric acid and sodium hydroxide react to produce liquid water with sodium chloride dissolved in it.

Explanation:

1.

Step1: Identify the reactants and products

Reactants: Solid lithium (\(Li\)) and liquid water (\(H_{2}O(l)\)). Products: Hydrogen gas (\(H_{2}(g)\)) and lithium hydroxide solution (\(LiOH(aq)\)).

Step2: Write the un - balanced equation

\(Li(s)+H_{2}O(l)
ightarrow H_{2}(g)+LiOH(aq)\)

Step3: Balance the equation

Multiply \(Li\) by \(2\), \(H_{2}O\) by \(2\), and \(LiOH\) by \(2\)
\(2Li(s)+2H_{2}O(l)
ightarrow H_{2}(g)+2LiOH(aq)\)

2.

Step1: Identify the reactants and products

Reactants: Solid sodium (\(Na(s)\)) and gaseous chlorine (\(Cl_{2}(g)\)). Products: Aqueous sodium chloride (\(NaCl(aq)\))

Step2: Write the un - balanced equation

\(Na(s)+Cl_{2}(g)
ightarrow NaCl(aq)\)

Step3: Balance the equation

Multiply \(Na\) by \(2\) and \(NaCl\) by \(2\)
\(2Na(s)+Cl_{2}(g)
ightarrow 2NaCl(aq)\)

3.

Step1: Identify the reactants and products

Reactant: Solid calcium carbonate (\(CaCO_{3}(s)\)). Products: Carbon dioxide gas (\(CO_{2}(g)\)), oxygen gas (\(O_{2}(g)\)) and solid calcium (\(Ca(s)\))

Step2: Write the un - balanced equation

\(CaCO_{3}(s)
ightarrow CO_{2}(g)+O_{2}(g)+Ca(s)\)

Step3: Balance the equation

Multiply \(CaCO_{3}\) by \(2\), \(CO_{2}\) by \(2\)
\(2CaCO_{3}(s)
ightarrow 2CO_{2}(g)+O_{2}(g)+2Ca(s)\)

4.

Step1: Identify the reactants and products

Reactants: Solid iron(II) sulfate (\(FeSO_{4}(s)\)) and barium chloride solution (\(BaCl_{2}(aq)\)). Products: Solid barium sulfate (\(BaSO_{4}(s)\)) and iron(II) chloride solution (\(FeCl_{2}(aq)\))

Step2: Write the un - balanced equation

\(FeSO_{4}(s)+BaCl_{2}(aq)
ightarrow BaSO_{4}(s)+FeCl_{2}(aq)\)

Step3: Check for balance

The equation is already balanced as the number of \(Fe\), \(S\), \(O\), \(Ba\), and \(Cl\) atoms are the same on both sides.

5.

Step1: Identify the reactants and products

Reactants: Hydrochloric acid solution (\(HCl(aq)\)) and sodium hydroxide solution (\(NaOH(aq)\)). Products: Liquid water (\(H_{2}O(l)\)) and sodium chloride solution (\(NaCl(aq)\))

Step2: Write the un - balanced equation

\(HCl(aq)+NaOH(aq)
ightarrow H_{2}O(l)+NaCl(aq)\)

Step3: Check for balance

The equation is already balanced as the number of \(H\), \(Cl\), \(Na\), and \(O\) atoms are the same on both sides.

Answer:

1. \(2Li(s)+2H_{2}O(l)

ightarrow H_{2}(g)+2LiOH(aq)\)

1. \(2Na(s)+Cl_{2}(g)

ightarrow 2NaCl(aq)\)

1. \(2CaCO_{3}(s)

ightarrow 2CO_{2}(g)+O_{2}(g)+2Ca(s)\)

1. \(FeSO_{4}(s)+BaCl_{2}(aq)

ightarrow BaSO_{4}(s)+FeCl_{2}(aq)\)

1. \(HCl(aq)+NaOH(aq)

ightarrow H_{2}O(l)+NaCl(aq)\)