Write balanced equations describing the reaction of Sr with each of the following: O2, S, Cl2,

Write balanced equations describing the reaction of Sr with...

Key Concepts

Types of Chemical Reactions

Different types of chemical reactions are involved when a metal reacts with various substances. These include synthesis reactions where elements combine to form a compound; redox (oxidation-reduction) reactions, where electrons are transferred; and acid-base reactions, particularly when metals react with acids to produce salts and hydrogen gas. Recognizing the type of reaction helps in predicting the products and balancing the equations properly.

Reactivity of Metals

This concept covers the tendency of metals, especially those in the alkaline earth group, to lose electrons and form positive ions when reacting with nonmetals or acids. Their reactivity is exploited in a variety of chemical reactions, including oxidation with oxygen, combination with halogens, and displacement reactions in acids and water.

Conservation of Mass

This fundamental principle states that matter is neither created nor destroyed in a chemical reaction. In writing balanced equations, it is essential to ensure that the number of atoms for each element is equal on both the reactant and product sides, reinforcing the idea that mass is conserved throughout the reaction.

Stoichiometry

Stoichiometry involves the quantitative relationships between reactants and products in a chemical reaction. It uses the coefficients in a balanced chemical equation to indicate the molar ratios, allowing for the calculation of amounts of substances consumed or produced during the reaction.

Transcript

00:01 So in this video, we're going to talk about question 24 from chapter 20, which says right balanced equations describing the reaction of strontium with each of the following, o2s, cl2, p4, h2, h2o, and hcl.

00:16 And i want to point out that all of this information is summarized in table 20 .7.

00:21 So if you need a summary, you can look there.

00:24 But we can also figure it out ourselves just by knowing that strontium likes to react to, lose two electrons to have its plus two charge to have the noble gas configuration, and then that ion is going to form ionic compounds.

00:41 So when we have strontium plus o2, the ionic compound will be between strontium cat ions with a plus two charge and oxygen anions.

00:53 Our oxygen usually takes a minus two charge.

00:56 It likes to gain two electrons to reach the noble gas configuration.

01:00 So we have plus 2 and minus 2.

01:02 Our charges are balanced, but we need to balance the elements, the atoms, in our equation.

01:09 So on the left -hand side, we have two oxygen atoms, and the right -hand side we have just one.

01:13 So we need a coefficient of 2.

01:16 So we have 2 -s -r -o, but now we have two strontium atoms on the right and just one on the left.

01:21 So we also need a coefficient of 2 in front of our strontium.

01:25 So the balanced chemical equation is 2 -s -r plus o2 yields 2 -sr.

01:29 Next we have the reaction between strontium and sulfur, and this is actually really similar because oxygen and sulfur are from the same column or group of the periodic table.

01:41 So we know that our strontium wants to form that plus two ions.

01:45 We have strontium plus two and then sulfur also forms a minus two ion just like oxygen is so we have plus two and minus two our charges are balanced and our elements are actually balanced as well, so this equation is already balanced.

01:59 We have s plus s yields sr.

02:02 Next we have the reaction of strontium with chlorine with cl2.

02:08 So again, our strontium is going to want to form that plus two ion.

02:12 And then it's going to form an ionic compound with chloride ions.

02:17 So the ion we form from chlorine is chloride with a minus one charge.

02:22 It's one of our halides.

02:25 So we have a minus one charge and a plus two charge.

02:29 So we need two chlorides to balance that.

02:33 So sr plus cl2 yields srcl2.

02:38 Next we have strontium plus p4.

02:42 So this time we're forming a slightly more complicated ionic compound.

02:48 So we know that our strontium is going to have a plus two charge.