2.48 grams.
<h3>Explanation</h3>
Start by finding the formula mass for cobalt (II) chloride and cobalt (II) chloride hexahydrate.
As a transition element in the middle d-block of the periodic table, cobalt can form ions with a plurality of charges. It is thus necessary to indicate its charge in systematic names of cobalt-containing formula.
The cation "cobalt" in the systematic name of the salt has the Roman numeral "(II)" attached to it in brackets. As a metal, cobalt forms positively-charged ion. The one here thu has charge of +2.
Chloride ions have charges -1. Charges cancel out to produce neutral compounds. Each cobalt cation in this salt would thus pair with two chloride anions. Hence the empirical formula: .
The prefix "<em>hexa-</em>" in the name cobalt (II) chloride <em>hexa</em>hydrate indicates that every formula unit of this salt contains six units of water. The hydrated salt thus has an empirical formula of .
Given the relative atomic mass for each of the elements, as seen on a modern periodic table of the elements:
- Cobalt- 58.93
- Chloride- 35.45
- Hydrogen- 1.008
- Oxygen- 16.00
Thus the formula mass of each compound
- Cobalt (II) chloride - 129.83
- Cobalt (II) chloride hexahydrate - 262.12
Cobalt (II) chloride hexahydrate decomposes under heat to produce cobalt (II) hexahydrate and water. Hence the equation:
Therefore
- Molar ratio:
- Mass ratio:
The mass ratio indicates that 262.12 grams of cobalt (II) chloride hexahydrate decomposes to produce 129.83 grams of its corresponding anhydrous salt. Accordingly, heating 5.00 grams of the hexahydrate would produce 2.48 grams of its anhydrate.
Mixing water and sugar is a physical change. A physical change is just a change in the form of the substance, whereas a chemical change is when the substance itself changes… chemically. An easy way to figure out which is which is trying to "undo" the change. If it can be undone, it is physical.
The answer is A. Many compounds are comprised of very different elements. For example, Sodium is a highly reactive group 1 solid metal that combusts when in contact with water, and Chlorine is a reactive group 17 gas that is used in the treatment of pool water; however, when you put them together, you get quite a common, non-toxic food additive: salt. Elements and compounds can sometimes resemble each other, but it certainly isn’t uncommon to see large differences between the two.
Answer:
a. 0,035M
Explanation:
For the reaction:
Ba(OH)₂(s) ⇄ Ba²⁺(aq) + 2OH⁻(aq)
Ksp is defined as:
Ksp = [Ba²⁺] [OH⁻]²
5x10⁻³ = [Ba²⁺] [OH⁻]²
if is added a solution of 1M of Ba²⁺:
5x10⁻³ = [1M] [OH⁻]²
The addition of barium hydroxide Ba(OH)₂ gives:
[Ba²⁺] = 1M + x
[OH⁻]² = 2x
Replacing:
5x10⁻³ = [1 + x] [2x]²
5x10⁻³ = 4x² + 4x³
Solutions are:
x = -1,00 M
x = -0,036 M
<em><u>x = 0,035 M</u></em> → Right answer, there are not negative concentrations.
Thus, solubility is
<em>a. 0,035M</em>
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I hope it helps!