Answer: The ion that contribute to water hardness are:
--> a. Ca2+
--> b. (HCO)3^- and
--> c. Mg2+
While K+ DOES NOT contribute to water hardness.
Explanation:
WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.
Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:
--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.
--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.
Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.
The correct answer is E. 50 grams
The solubility of Ammonium Chloride has an increasing trend as the temperature increases. Experiments show that the solubility at 323K is approximately 50.4 grams per 100 grams o water thus this value is close to choice D, 50 grams
Answer:
Atoms gain or lose electrons
Explanation:
Answer:
1) D; 2) B
Explanation:
1) <em>Conservation of atoms
</em>
D is correct.
It has four atoms of H and two of O on each side of the reaction arrow.
A. <em>Wrong</em>. It has the same number of H and O on each side, but it has the <em>wrong product</em>. The reaction forms O₂ molecules, not O atoms.
B. <em>Wrong</em>. Atoms are balanced, but the <em>products are incorrect</em>.
C. <em>Wrong</em>. Atoms are balanced, but the <em>reactants are incorrect</em>.
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2) <em>Chemical equations
</em>
B is correct.
The atoms are balanced, and the equation shows the correct formulas of the molecules.
A. <em>Wrong</em>. Atoms are balanced, and the formulas are correct, but the equation is <em>not in its simplest form</em>. The coefficients are not in their lowest terms. We must divide every coefficient by six to get the correct equation: H₂ + Cl₂ ⟶ 2HCl.
C. <em>Wrong</em>. The <em>reactants are incorrect</em>, and the equation is <em>not in its lowest terms</em>.
D. <em>Wrong</em>. The <em>reactants are incorrect</em>.