Dr Bob
Is it true that only TWO molecules of water are required to balance the equation for the reaction of HCL with Calcium Hydroxide.(calcium chloride is the other product....why???
Thanks andy
HCl + Ca(OH)2 ==> CaCl2 + H2O
I start by seeing 2 Cl on the right. I fix that with a 2HCl
2HCl + Ca(OH)2 --> CaCl2 + H2O
So Ca and Cl now balance. That leaves only H and O. I usually count what I have on the left (since the 2 for HCl and 1 for Ca(OH)2 seem to be ok.) I see 4 H atoms on the left (2 from HCl and 2 from Ca(OH)2. So I add a 2 for H2O on the right.
2HCl + Ca(OH)2 ==> CaCl2 + 2H2O.
So yes, water requires a 2. WHY? Because everything balances with 2H2O. Stick any other number there and it won't balance.
thanks so much....andy
To balance the equation for the reaction of hydrochloric acid (HCl) with calcium hydroxide (Ca(OH)2), we need to ensure that the number of each type of atom on both sides of the equation is the same.
The reaction between HCl and Ca(OH)2 can be represented as follows:
HCl + Ca(OH)2 → CaCl2 + H2O
Let's break it down and balance each atom one by one:
1. Hydrogen (H) atoms:
On the left side: 1 H atom (from HCl)
On the right side: 2 H atoms (from H2O)
To balance the number of hydrogen atoms, we need to double the HCl:
2 HCl + Ca(OH)2 → CaCl2 + 2 H2O
2. Chlorine (Cl) atoms:
On the left side: 2 Cl atoms (from 2 HCl)
On the right side: 2 Cl atoms (from CaCl2)
The chlorine atoms are already balanced.
3. Calcium (Ca) atoms:
On the left side: 1 Ca atom (from Ca(OH)2)
On the right side: 1 Ca atom (from CaCl2)
The calcium atoms are already balanced.
4. Oxygen (O) atoms:
On the left side: 2 O atoms (from Ca(OH)2)
On the right side: 2 O atoms (from 2 H2O) + 2 O atoms (from CaCl2)
To balance the number of oxygen atoms, we need to double the CaCl2:
2 HCl + Ca(OH)2 → 2 CaCl2 + 2 H2O
Therefore, to balance the equation correctly, we need two molecules of HCl and one molecule of Ca(OH)2, resulting in two molecules of CaCl2 and two molecules of H2O as the products.
The reason calcium chloride (CaCl2) is formed as the other product is because when HCl reacts with Ca(OH)2, the hydrochloric acid (HCl) donates a hydrogen (H+) ion, while calcium hydroxide (Ca(OH)2) donates a hydroxide (OH-) ion. The combination of the H+ and OH- ions forms water (H2O), and the remaining calcium ion (Ca2+) and chloride ion (Cl-) combine to form calcium chloride (CaCl2).