why should we write bracket for hydroxide in calcium hydroxide
Answers
Explanation:
Ca(OH)2 is written as such because OH is a complex ion and to show that we put brackets
Answer:
Ca(OH)2 is an ionic compound, in which Ca is the cation and OH is the anion. Ca (calcium) has a charge of 2+, since it is in group 2 on the periodic table. OH (hydroxide) is a polyatomic ion with a charge of -1.
The chemical formula of an ionic compound shows the smallest unit of the ionic compound that has a neutral charge, so we balance the charges of the two ions using subscripts. We can calculate that we need 1 calcium cation and 2 hydroxide anions to achieve a neutral charge. (If you add the charge of one calcium cation and two hydroxide anions, the resulting charge is 0, as shown in the following equation.)
1(+2)1(+2)+2(−1)=0+2(−1)=0
Since OH is one polyatomic ion, it is put in brackets to show that the subscript 2 applies to the entire molecule, not just to the H atom.
*Think brackets in math: 2(x+y)2(x+y) shows that the scalar multiple 2 applies to both x and y, and the expression is equivalent to 2x+2y2x+2y. However, 2x+y2x+y means that the scalar multiple 2 only applies to x, but not y.
In the case of this chemical formula, (OH)2 would be numerically equivalent to O2H2 (even though that’s not the correct notation for it in a chemical formula), but not to OH2 (one O and 2 H’s).
Explanation: