Answer:
Blank #1: Polyatomic
Blank #2: 2 (see explanation)
Blank #3: 1 (see explanation)
Explanation
Both the ammonium ion and the sulfate ion contain more than one atom in each ion. The two species are thus polyatomic. The chloride ion , for example, is monoatomic.
Superscripts above formulae of the ions indicate their charge. Each ammonium ion carries a positive one (+1) charge. Each sulfate ion carries a charge of negative two (-2).
Ammonium sulfate is an ionic compound. A sample of this compound contain myriads of ammonium ions and sulfate ions. The ions are packed in three-dimensional lattices. Thus unlike water, ammonium sulfate does not exist as molecules in nature.
Assuming that the second and third blanks refers to a formula unit, rather than a molecule, of ammonium sulfate. The empirical formula of ammonium sulfate gives the minimum whole-number ratio between the two ions in a sample.
Charges shall balance between the two ions. Ammonium ions are of charge +1. Sulfate ions are of charge -2. The sample shall thus contain two ammonium ions for every one sulfate ion.
The empirical formula of ammonium sulfate is therefore .
There are thus two ammonium ions and one sulfate ion in each formula unit of ammonium sulfate.
For the purpose we will use solution dilution equation:
c1V1=c2V2
Where, c1 - concentration of stock solution; V1 - volume of stock solution needed to make the new solution; c2 - final concentration of new solution; V2 - final volume of new solution.
c1 = 100%
c2 = 75%
V1 = 1 gal
V2 = ?
When we plug values into the equation, we get following:
100 x 1 = 75 x V2
V2= 100/75 = 1.33 gal
Now we can determine the necessary volume of water:
V(water)= V2 - V1 = 1.33 - 1 = 0.33 gal water should be added
Answer:
A. air expands when heated.
Explanation:
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Answer:
8. A golf ball feels heavier than a table-tennis ball because a golf ball is denser; that is, it has more mass in a similar volume.
10.
The density of the unknown substance is 10.50 g/mL. According to the table, the substance that has the same amount of density is silver. Therefore, the unknown substance is silver.
Explanation:
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